C. Wind velocity in the afternoon is very high resulting in dust storm or ...... bleached dry ginger, ginger powder, ginger oil, ginger oleoresin, ginger ale, ginger.
VEGETABLE PRODUCTION UNDER CHANGING CLIMATE SCENARIO st
st
(1 September – 21 September)
COMPILED AND EDITED BY
M L Bhardwaj H Dev Sharma Manish Kumar Ramesh Kumar Sandeep Kansal Kuldeep Thakur Shiv Pratap Singh Dharminder Kumar Santosh Kumari Meenu Gupta Vipin Sharma
2012
FOREWORD The importance of vegetables in providing balanced diet and nutritional security has been realised world over. Vegetables are now recognized as health food globally and play important role in overcoming micronutrient deficiencies and providing opportunities of higher farm income. The worldwide production of vegetables has tremendously gone up during the last two decades and the value of global trade in vegetables now exceeds that of cereals. Hence, more emphasis is being given in the developing countries like India to promote cultivation of vegetables. Development of hybrid varieties, integrated insect-pest and diseases management practices, integrated nutrient management and standardizing improved agrotechniques including organic farming have changed the scenario of vegetables production in the country. In short, productivity, quality and post harvest management of vegetables will have to be improved to remain competitive in the next decades. The major objectives of reducing malnutrition and alleviating poverty in developing countries through improved production and consumption of safe vegetables will involve adaptation of current vegetable systems to the potential impact of climate change. Genetic populations are being developed to introgress and identify genes conferring tolerance to stresses and at the same time generate tools for gene isolation, characterization and genetic engineering. Furthermore, agronomic practices that conserve water and protect vegetable crops from sub-optimal environmental conditions must be continuously enhanced and made easily accessible to farmers in the developing world. Current, and new, technologies being developed through plant stress physiology research can potentially contribute to mitigate threats from climate change on vegetable production. However, farmers in developing countries are usually small-holders, have fewer options and must rely heavily on available resources. Thus, technologies that are simple, affordable, and accessible must be used to increase the resilience of farms in less developed countries. Finally, capacity building and education are key components of a sustainable adaptation strategy to climate change. Hence, topic "Vegetable production under changing climate scenario" chosen for the present training under Centre of Advanced Faculty Training in Horticulture (Vegetables) is appropriate and relevant under the present circumstances of agriculture. I am sure, the lectures delivered by the faculty of this university, invited speakers as well as the exposure visits conducted during the training might have benefited the participants . Further, the giving compilation of lectures in the form of compendium to the participants of training will also help in strengthening the teaching programmes in their respective institutions in this area. All the faculty members and staff of the department of Vegetable Science deserve appreciation for the efforts made in the smooth conduct of the training programme.
(K R Dhiman) Vice Chancellor
ACKNOWLEDGEMENTS Vegetable being an effective alternative to protective food, have become an essential component of human diet. Although there has been spectacular increase in the vegetable production from 15 million tonnes during 1950 to 146 million tonnes during the current year, but we still need to produce more vegetables to meet the minimum requirement of at least providing 300 g of vegetables/day/captia. The target can only be achieved through combined use of growing high yielding varieties having resistance to various biotic and abiotic stresses with improved nutritional quality and matching agrotechniques by utilizing available resources. Developing countries like India whose geographical parts comprises of mountainous regions comprising of Himalayas, central plateau region, northern plains, coastal regions, deltas etc. are particularly vulnerable for climate change as little change in the climate will disturb the whole ecology and in-turn the traditional pattern of vegetables being grown in these regions. Latitudinal and altitudinal shifts in ecological and agro-economic zones, land degradation, extreme geophysical events, reduced water availability, and rise in sea level are the factors which effect the vegetable production. Unless measures are undertaken to adapt to the effects of climate change, vegetable production in the developing countries like India will be under threat. Hence, the present training programme organised by Centre of Advanced Faculty Training in Horticulture (Vegetables) on "Vegetable production under changing climate scenario" is important as it will sharpen the focus on production of vegetables under changing climatic conditions. The Centre of Advanced Faculty Training in Horticulture (Vegetables) gratefully acknowledges the patronage provided by Dr. KR Dhiman, Hon'ble Vice-Chancellor of this University. The financial assistance received from the Indian Council of Agricultural Research in conducting the training and generating useful instructional material along with assistance for need based postgraduate research is also highly acknowledged. The Centre also appreciates sincere efforts of all the resource personnel within and outside this university for interaction with the participants. All the faculty members and staff of Department of Vegetable Science, Deans and Directors of the University, other Statutory Officers and Heads of the Departments deserve special thanks for their help and co-operation in making this training programme a success.
(M L Bhardwaj) Director, CAFT
CONTENTS Sr.No.
Title
Page(s)
1.
Effect of climate change on vegetable production in India ML Bhardwaj
1-12
2.
Challenges and opportunities of vegetable cultivation under changing climate scenario ML Bhardwaj
13-18
3.
High altitude protected vegetable production Brahma Singh
19-28
4.
Protected cultivation of vegetables in Indian plains Mathura Rai
29-36
5.
Relevance of conservation agriculture under climate change RK Sharma
37-43
6.
Production technology of ginger under changing climate H Dev Sharma and Vipin Sharma
44-52
7.
Production technology of turmeric under changing climate H Dev Sharma and Vipin Sharma
53-58
8.
Protected cultivation of high value vegetable crops Manish Kumar
59-62
9.
Pre and post harvest factors influencing the quality of vegetable seeds HS Kanwar and DK Mehta
63-67
10.
Impact of climate change on quality seed production of important temperate vegetable crops Ramesh Kumar, Sandeep Kumar, Ashok Thakur and Sanjeev Kumar
68-74
11.
Vegetable production and seed production under temperate conditions 75-82 Amit Vikram
12.
Production technology of cucumber under changed climatic conditions Ramesh Kumar, Sandeep Kumar, KS Thakur and Dharminder Kumar
83-87
13.
Production technology of vegetable crops under changing climate with reference to organic vegetable production Kuldeep Singh Thakur, Ramesh Kumar and Dhaminder Kumar
88-91
14.
Role of biofertilizers in enhancing the vegetable productivity under organic farming systems Kuldeep Singh Thakur and Dhaminder Kumar
92-94
15.
Production potential of under exploited vegetable crops Dharminder Kumar, Ramesh Kumar, KS Thakur, Ashok Thakur, Prabal Thakur and Sandeep Kumar
95-100
16.
Off-season tomato production in North Western Himalayas under changing climate Shiv Pratap Singh
101-103
17.
Influence of climate change in capsicum production Santosh Kumari
104-107
18.
Efficient irrigation management practices in vegetable crops JN Raina
108-112
19.
Impact of climate change on vegetable crop production vis a vis mitigation and adaptation strategies Satish Kumar Bhardwaj
113-120
20.
New pathological threats to vegetable crops and their management under changing climatic conditions RC Sharma
121-123
21.
Biotic factors and their management under changing climate RC Sharma and Meenu Gupta
124-130
22.
Integrated disease management in cole crops NP Dohroo
131-135
23.
Diagnosis and management of vegetable diseases Sandeep Kansal
136-142
24.
Integrated disease management in solanaceous and leguminous vegetables Sandeep Kansal
143-150
25.
Disease management scenario in changing climatic conditions Harender Raj Gautam
151-158
26.
Eco-friendly techniques for management of diseases in spice crops Meenu Gupta
159-166
27.
Integrated pest management in solanceous and leguminous vegetable crops KC Sharma
167-174
28.
Judicious use of pesticides to lower residue in vegetable production RS Chandel, ID Sharma and SK Patyal
175-181
29.
Management of pollinators of vegetable crops under changing climatic scenario R K Thakur and Jatin Soni
182-188
30.
Vegetable intercropping in sugarcane for greater productivity and profitability RK Sharma and Samar Singh
189-195
31.
Role of crop modelling in mitigating effects of climate change on crop production R S Spehia
196-202
32.
Physiological disorders in vegetable crops: causes and management 203-208 Santosh Kumari
33.
Weed management in vegetable crops Dharminder Kumar, Manish Kumar, Ramesh Kumar, KS Thakur, Amit Vikram and Sandeep Kumar
209-217
34.
Biochemical constituents and quality attributes in spices Vipin Sharma and H Dev Sharma
218-222
35.
Techniques of quality analysis in spices Vipin Sharma and H Dev Sharma
223-227
36.
Recent techniques in postharvest management & processing of vegetables PC Sharma, Manisha Kaushal and Anil Gupta
228-234
List of participants
i-ii
Effect of Climate Change on Vegetable Production in India ML Bhardwaj Department of Vegetable Science Dr YS Parmar University of Horticulture and Forestry, Nauni-173 230 Solan
A significant change in climate on a global scale will impact vegetable cultivation and agriculture as a whole; consequently affect the world's food supply. Climate change per se is not necessarily harmful; the problems arise from extreme events that are difficult to predict. More erratic rainfall patterns and unpredictable high temperature spells consequently reduce crop productivity. Developing countries in the tropics will be particularly vulnerable. Latitudinal and altitudinal shifts in ecological and agro-economic zones, land degradation, extreme geophysical events, reduced water availability, and rise in sea level and salinization make it difficult to cultivate the traditional vegetables in particular zones in the world. Unless measures are undertaken to mitigate the effects of climate change, food security in developing countries will be under threat and will jeopardize the future of the vegetable growers in these countries. Vegetables are the best resource for overcoming micronutrient deficiencies and provide smallholder farmers with much higher income and more jobs per hectare than staple crops. The worldwide production of vegetables has doubled over the past quarter century and the value of global trade in vegetables now exceeds that of cereals. Vegetables are generally sensitive to environmental extremes, and thus high temperatures and limited soil moisture are the major causes of low yields and will be further magnified by climate change. Environmental constraints limiting vegetable productivity Environmental stress is the primary cause of crop losses worldwide, reducing average yields for most major crops by more than 50%. The tropical vegetable production environment is a mixture of conditions that varies with season and region. Climatic changes will influence the severity of environmental stress imposed on vegetable crops. Moreover, increasing temperatures, reduced irrigation water availability, flooding, and salinity will be major limiting factors in sustaining and increasing vegetable productivity. Extreme climatic conditions will also negatively impact soil fertility and increase soil erosion. Thus, additional fertilizer application or improved nutrient-use efficiency of crops will be needed to maintain productivity or harness the potential for enhanced crop growth due to increased atmospheric CO2.
The response of plants to environmental stresses depends on the plant developmental stage and the length and severity of the stress. Plants may respond similarly to avoid one or more stresses through morphological or biochemical mechanisms. Environmental interactions may make the stress response of plants more complex or influence the degree of impact of climate change. Measures to adapt to these climate change-induced stresses are critical for sustainable tropical vegetable production. High temperatures Temperature limits the range and production of many crops. In the tropics, high temperature conditions are often prevalent during the growing season and, with a changing climate, crops in this area will be subjected to increased temperature stress. Analysis of climate trends in tomato-growing locations suggests that temperatures are rising and the severity and frequency of above-optimal temperature episodes will increase in the coming decades. Tomatoes are strongly modified by temperature alone or in conjunction with other environmental factors (Abdalla & Verkerk 1968). High temperature stress disrupts the biochemical reactions fundamental for normal cell function in plants. It primarily affects the photosynthetic functions of higher plants. High temperatures can cause significant losses in tomato productivity due to reduced fruit set, and smaller and lower quality fruits. Pre-anthesis temperature stress is associated with developmental changes in the anthers, particularly irregularities in the epidermis and endothesium, lack of opening of the stromium, and poor pollen formation. In pepper, high temperature exposure at the pre-anthesis stage did not affect pistil or stamen viability, but high post-pollination temperatures inhibited fruit set, suggesting that fertilization is sensitive to high temperature stress. Symptoms causing fruit set failure at high temperatures in tomato; includes bud drop, abnormal flower development, poor pollen production, dehiscence, and viability, ovule abortion and poor viability, reduced carbohydrate availability, and other reproductive abnormalities. In addition, significant inhibition of photosynthesis occurs at temperatures above optimum, resulting in considerable loss of potential productivity. Drought Unpredictable drought is the single most important factor affecting world food security and the catalyst of the great famines of the past. The world's water supply is fixed, thus increasing population pressure and competition for water resources will make the effect of successive droughts more severe. Inefficient water usage all over the world and inefficient distribution systems in developing countries further decreases water availability. Water availability is expected to be highly sensitive to climate change and severe water stress conditions will affect crop 2
productivity, particularly that of vegetables. In combination with elevated temperatures, decreased precipitation could cause reduction of irrigation water availability and increase in evapo-transpiration, leading to severe crop water-stress conditions. Vegetables, being succulent products by definition, generally consist of greater than 90% water (AVRDC 1990). Thus, water greatly influences the yield and quality of vegetables; drought conditions drastically reduce vegetable productivity. Drought stress causes an increase of solute concentration in the environment (soil), leading to an osmotic flow of water out of plant cells. This leads to an increase of the solute concentration in plant cells, thereby lowering the water potential and disrupting membranes and cell processes such as photosynthesis. The timing, intensity, and duration of drought spells determine the magnitude of the effect of drought. Salinity Vegetable production is threatened by increasing soil salinity particularly in irrigated croplands which provide 40% of the world's food. Excessive soil salinity reduces productivity of many agricultural crops, including most vegetables which are particularly sensitive throughout the ontogeny of the plant. According to the United States Department of Agriculture (USDA), onions are sensitive to saline soils, while cucumbers, eggplants, peppers, and tomatoes, amongst the main crops moderately sensitive. In hot and dry environments, high evapo-transpiration results in substantial water loss, thus leaving salt around the plant roots which interferes with the plant's ability to uptake water. Physiologically, salinity imposes an initial water deficit that results from the relatively high solute concentrations in the soil, causes ion-specific stresses resulting from altered K+/Na+ ratios, and leads to a build + up in Na and Cl concentrations that are detrimental to plants. Plant sensitivity to salt stress is reflected in loss of turgor, growth reduction, wilting, leaf curling and epinasty, leaf abscission, decreased photosynthesis, respiratory changes, loss of cellular integrity, tissue necrosis, and potentially death of the plant. Salinity also affects agriculture in coastal regions which are impacted by low-quality and highsaline irrigation water due to contamination of the groundwater and intrusion of saline water due to natural or man-made events. Salinity fluctuates with season, being generally high in the dry season and low during rainy season when freshwater flushing is prevalent. Furthermore, coastal areas are threatened by specific, saline natural disasters which can make agricultural lands unproductive, such as tsunamis which may inundate low-lying areas with seawater. Although the seawater rapidly recedes, the groundwater contamination and subsequent osmotic stress causes crop losses and affects soil fertility. In the inland areas, traditional water wells are commonly used for irrigation water in many countries. The bedrock deposit contains salts and the water from these wells are becoming more saline, thus affecting irrigated vegetable production in these areas. 3
Flooding Vegetable production occurs in both dry and wet seasons in the tropics. However, production is often limited during the rainy season due to excessive moisture brought about by heavy rain. Most vegetables are highly sensitive to flooding and genetic variation with respect to this character is limited, particularly in tomato. In general, damage to vegetables by flooding is due to the reduction of oxygen in the root zone which inhibits aerobic processes. Flooded tomato plants accumulate endogenous ethylene that causes damage to the plants. Low oxygen levels stimulate an increased production of anethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), in the roots. The rapid development of epinastic growth of leaves is a characteristic response of tomatoes to water-logged conditions and the role of ethylene accumulation has been implicated. The severity of flooding symptoms increases with rising temperatures; rapid wilting and death of tomato plants is usually observed following a short period of flooding at high temperatures. The Need for Adaptation to Climate Change Potential impacts of climate change on agricultural production will depend not only on climate per se, but also on the internal dynamics of agricultural systems, including their ability to adapt to the changes. Success in mitigating climate change depends on how well agricultural crops and systems adapt to the changes and concomitant environmental stresses of those changes on the current systems. Farmers in developing countries of the tropics need tools to adapt and mitigate the adverse effects of climate change on agricultural productivity, and particularly on vegetable production, quality and yield. Current, and new, technologies being developed through plant stress physiology research can potentially contribute to mitigate threats from climate change on vegetable production. However, farmers in developing countries are usually small-holders, have fewer options and must rely heavily on resources available in their farms or within their communities. Thus, technologies that are simple, affordable, and accessible must be used to increase the resilience of farms in less developed countries. AVRDC – The World Vegetable Center has been working to address the effect of environmental stress on vegetable production. Germplasm of the major vegetable crops which are tolerant of high temperatures, flooding and drought has been identified and advanced breeding lines are being developed. Efforts are also underway to identify nitrogen-use efficient germplasm. In addition, development of production systems geared towards improved water-use efficiency and expected to mitigate the effects of hot and dry conditions in vegetable production systems are top research and development priorities.
4
Enhancing Vegetable Production Systems Various management practices have the potential to raise the yield of vegetables grown under hot and wet conditions of the lowland tropics. AVRDC – The World Vegetable Center has developed technologies to alleviate production challenges such as limited irrigation water and flooding, to mitigate the effects of salinity, and also to ensure appropriate availability of nutrients to the plants. Strategies include modifying fertilizer application to enhance nutrient availability to plants, direct delivery of water to roots (drip irrigation), grafting to increase flood and disease tolerance, and use of soil amendments to improve soil fertility and enhance nutrient uptake by plants. Water-saving irrigation management The quality and efficiency of water management determine the yield and quality of vegetable products. The optimum frequency and amount of applied water is a function of climate and weather conditions, crop species, variety, stage of growth and rooting characteristics, soil water retention capacity and texture, irrigation system and management factor. Too much or too little water causes abnormal plant growth, predisposes plants to infection by pathogens, and causes nutritional disorders. If water is scarce and supplies are erratic or variable, then timely irrigation and conservation of soil moisture reserves are the most important agronomic interventions to maintain yields during drought stress. There are several methods of applying irrigation water and the choice depends on the crop, water supply, soil characteristics and topography. Application of irrigation water could be through overhead, surface, drip, or sub-irrigation systems. Surface irrigation methods are utilized in more than 80% of the world's irrigated lands yet its field level application efficiency is often 40-50%. To generate income and alleviate poverty of the smallholder farmers in developing countries, AVRDC – The World Vegetable Center and other institutions promote affordable, small-scale drip irrigation technologies developed by the International Development Enterprises (IDE). Drip irrigation delivers water directly to plants through small plastic tubes. IDE states that water losses due to run-off and deep percolation are minimized and water savings of 5080% are achieved when compared to most traditional surface irrigation methods. Crop production per unit of water consumed by plant evapo-transpiration is typically increased by 10-50%. Thus, more plants can be irrigated per unit of water by drip irrigation, and with less labor. In Nepal, cauliflower yields using low-cost drip irrigation were not significantly different from those achieved by hand watering; however the long-term economic and labor benefits were greater using the low-cost drip irrigation. The water-use efficiency by chili pepper was significantly higher in drip irrigation compared to furrow irrigation, with higher efficiencies observed with high delivery rate drip irrigation regimes (AVRDC 2005). For drought tolerant crop 5
like watermelon, yield differences between furrow and drip irrigated crops were not significantly different; however, the incidence of Fusarium wilt was reduced when a lower drip irrigation rate was used. In general, the use of low-cost drip irrigation is cost effective, labor-saving, and allows more plants to be grown per unit of water, thereby both saving water and increasing farmers' incomes at the same time. Cultural practices that conserve water and protect crops Various crop management practices such as mulching and the use of shelters and raised beds help to conserve soil moisture, prevent soil degradation, and protect vegetables from heavy rains, high temperatures, and flooding. The use of organic and inorganic mulches is common in high-value vegetable production systems. These protective coverings help reduce evaporation, moderate soil temperature, reduce soil runoff and erosion, protect fruits from direct contact with soil and minimize weed growth. In addition, the use of organic materials as mulch can help enhance soil fertility, structure and other soil properties. Rice straw is abundant in rice-growing areas of the tropics and generally recommended for summer tomato production. The benefits of rice straw mulch on fruit yield of tomato have been demonstrated in Taiwan (AVRDC 1981). In India, mulching improved the growth of eggplant, okra, bottle gourd, round melon, ridge gourd, and sponge gourd compared to the nonmulched. Yields were the highest when polythene and sarkanda (Saccharum spp. and Canna spp.) were used as mulching materials. In the lowland tropics where temperatures are high, dark-colored plastic mulch is recommended in combination with rice straw. Dark plastic mulch prevents sunlight from reaching the soil surface and the rice straw insulates the plastic from direct sunlight thereby preventing the soil temperature rising too high during the day. During the hot rainy season, vegetables such as tomatoes suffer from yield losses caused by heavy rains. Simple, clear plastic rain shelters prevent water logging and rain impact damage on developing fruits, with consequent improvement in tomato yields. Fruit cracking and the number of unmarketable fruits are also reduced. Elimination of flooding and rain damage, as well as the reduced air temperature, was responsible for the higher yields of the crops grown under plastic shelters. Another form of shelter using shade cloth can be used to reduce temperature stress. Shade shelters also prevent damage from direct rain impact and intense sunlight. Planting vegetables in raised beds can ameliorate the effects of flooding during the rainy season (AVRDC 1979, 1981). Yields of tomatoes increased with bed height, most likely due to improved drainage and reduction of anoxic stress. Improved stress tolerance through grafting Grafting vegetables originated in East Asia during the 20th century and is currently common practice in Japan, Korea and some European countries. Grafting, 6
in this context, involves uniting of two living plant parts (rootstock and scion) to produce a single growing plant. It has been used primarily to control soil-borne diseases affecting the production of fruit vegetables such as tomato, eggplant, and cucurbits. However, it can provide tolerance to soil-related environmental stresses such as drought, salinity, low soil temperature and flooding if appropriate tolerant rootstocks are used. Grafting of eggplants was started in the 1950s, followed by grafting of cucumbers and tomatoes in the 1960s and 1970s. it was found that melons grafted onto hybrid squash rootstocks were more salt tolerant than the non-grafted melons. However, tolerance to salt by rootstocks varies greatly among species, such that rootstocks from Cucurbita spp. are more tolerant of salt than rootstocks from Lagenaria siceraria. Grafted plants were also more able to tolerate low soil temperatures. Solanum lycopersicum x S. habrochaites rootstocks provide tolerance of low soil o o temperatures (10 C to 13 C) for their grafted tomato scions, while eggplants grafted onto S. integrifolium x S. melongena rootstocks grew better at lower temperatures o o (18 C to 21 C) than non-grafted plants. Vegetables generally are unable to tolerate excessive soil moisture. Tomatoes in particular are considered to be one of the vegetable crops most sensitive to excess water. In the tropics, heavy rainfall with poor drainage induces water-logged conditions that reduce oxygen availability in the soil thereby causing wilting, chlorosis, leaf epinasty, and ultimately death of the tomato plants. Genetic variability for tolerance of excess soil moisture is limited or inadequate to prevent losses. Research at AVRDC - The World Vegetable Center has shown that many accessions of eggplant are highly tolerant of flooding. Thus, the Center developed grafting techniques to improve the flood tolerance of tomato using eggplant rootstocks which were identified with good grafting compatibility with tomato and high tolerance to excess soil moisture. Tomato scions grafted onto eggplant rootstock grow well and produce acceptable yields during the rainy season. In addition to protection against flooding, some eggplant genotypes are drought tolerant and eggplant rootstocks can therefore provide protection against limited soil moisture stress. Developing Climate-Resilient Vegetables Improved, adapted vegetable germplasm is the most cost-effective option for farmers to meet the challenges of a changing climate. However, most modern cultivars represent a limited sampling of available genetic variability including tolerance to environmental stresses. Breeding new varieties, particularly for intensive, high input production systems in developed countries is required to be done.
7
Superior varieties adapted to a wider range of climatic conditions could result from the discovery of novel genetic variation for tolerance to different biotic and abiotic stresses. Genotypes with improved attributes conditioned by superior combinations of alleles at multiple loci could be identified and advanced. Improved selection techniques are needed to identify these superior genotypes and associated traits, especially from wild, related species that grow in environments which do not support the growth of their domesticated relatives that are cultivated varieties. Plants native to climates with marked seasonality are able to acclimatize more easily to variable environmental conditions and provide opportunities to identify genes or gene combinations which confer such resilience. Tolerance to high temperatures The World Vegetable Center has developed tomatoes and Chinese cabbage with general adaptation to hot and humid tropical environments and low-input cropping systems since the early 1970s. This has been achieved by developing heattolerant and disease-resistant breeding lines. The Center has made significant contributions to the development of heat-tolerant tomato and Chinese cabbage lines and the subsequent release of adapted, tropical varieties worldwide. The key to achieving high yields with heat tolerant cultivars is the broadening of their genetic base through crosses between heat tolerant tropical lines and disease resistant temperate or winter varieties. The heat tolerant tomato lines were developed using heat tolerant breeding lines and landraces from the Philippines (e.g. VC11-3-1-8, VC 11-2-5, Divisoria-2) and the United States (e.g. Tamu Chico III, PI289309). However, lower yields in the heat tolerant lines are still a concern. More heat tolerant varieties are required to meet the needs of a changing climate, and these must be able to match the yields of conventional, non-heat tolerant varieties under non-stress conditions. A wider range of genotypic variation must be explored to identify additional sources of heat tolerance. An AVRDC - breeding line, CL5915, has demonstrated high levels of heat tolerance in Southeast Asia and the Pacific. The fruit set of CL5915 ranges from 15% - 30% while there is complete o absence of fruit set in heat-sensitive lines in mean field temperatures of 35 C. Drought tolerance and water-use efficiency Plants resist water or drought stress in many ways. In slowly developing water deficit, plants may escape drought stress by shortening their life cycle. However, the oxidative stress of rapid dehydration is very damaging to the photosynthetic processes, and the capacity for energy dissipation and metabolic protection against reactive oxygen species is the key to survival under drought conditions. Tissue tolerance to severe dehydration is not common in crop plants but is found in species native to extremely dry environments. Genetic variability for 8
drought tolerance in S. lycopersicum is limited and inadequate. The best source of resistance is from other species in the genus Solanum. The Tomato Genetics Resource Center (TGRC) at the University of California, Davis has assembled a set of the putatively stress tolerant tomato germplasm that includes accessions of S. cheesmanii, S. chilense, S. lycopersicum, S. lycopersicum var. cerasiforme, S. pennellii, S. peruvianum and S. pimpinellifolium. S. chilense and S. pennelli are indigenous to arid and semi-arid environments of South America. Both species produce small green fruit and have an indeterminate growth habit. S chilense is adapted to desert areas of northern Chile and often found in areas where no other vegetation grows. S. chilense has finely divided leaves and well-developed root system. S. chilense has a longer primary root and more extensive secondary root system than cultivated tomato. Drought tests show that S. chilense is five times more tolerant of wilting than cultivated tomato. S. pennellii has the ability to increase its water use efficiency under drought conditions unlike the cultivated S. lycopersicum (O'Connell et al. 2007). It has thick, round waxy leaves, is known to produce acylsugars in its trichomes, and its leaves are able to take up dew. Transfer and utilization of genes from these drought resistant species will enhance tolerance of tomato cultivars to dry conditions, although wide crosses with S. pennellii produce fertile progenies, S. chilense is cross-incompatible with S. lycopersicum and embryo rescue through tissue culture is required to produce progeny plants. Research at AVRDC and other institutions is in progress to identify the genetic factors underlying drought tolerance in S. chilense and S. pennellii, and to transfer these factors into cultivated tomatoes. Tolerance to saline soils and irrigation water Attempts to improve the salt tolerance of crops through conventional breeding programs have very limited success due to the genetic and physiologic complexity of this trait. In addition, tolerance to saline conditions is a developmentally regulated, stage-specific phenomenon; tolerance at one stage of plant development does not always correlate with tolerance at other stages. Success in breeding for salt tolerance requires effective screening methods, existence of genetic variability, and ability to transfer the genes to the species of interest. Most commercial tomato cultivars are moderately sensitive to increased salinity and only limited variation exists in cultivated species. Genetic variation for salt tolerance during seed germination in tomato has been identified within cultivated and wild species. In pepper, salt stress significantly decreases germination, shoot height, root length, fresh and dry weight, and yield. Pepper genotypes Demre, Ilica 250, 11-B-14, Bagci Carliston, Mini Aci Sivri, Yalova Carliston, and Yaglik 28 can be useful as sources of genes to develop pepper
9
cultivars with improved germination under salt stress. Related wild tomato species have shown strong salinity tolerance and are sources of genes as coastal areas are common habitat of some wild species. Studies have identified potential sources of resistance in the wild tomato species S. cheesmanii, S. peruvianum, S pennelii, S. pimpinellifolium, and S. habrochaites. Attempts to transfer quantitative trait loci (QTLs) and elucidate the genetics of salt tolerance have been conducted using populations involving wild species. Elucidation of mechanism of salt tolerance at different growth periods and the introgression of salinity tolerance genes into vegetables would accelerate development of varieties that are able to withstand high or variable levels of salinity compatible with different production environments. Climate-Proofing through Genomics and Biotechnology Increasing crop productivity in unfavorable environments will require advanced technologies to complement traditional methods which are often unable to prevent yield losses due to environmental stresses. In the past decade, genomics has developed from whole genome sequencing to the discovery of novel and high throughput genetic and molecular technologies. Genes have been discovered and gene functions understood. This has opened the way to genetic manipulation of genes associated with tolerance to environmental stresses. These tools promise more rapid, and potentially spectacular, returns but require high levels of investment. Many activities using these genetic and molecular tools are in place, with some successes. National and international institutes are re-tooling for plant molecular genetic research to enhance traditional plant breeding and benefit from the potential of genetic engineering to increase and sustain crop productivity. QTLs and gene discovery for tolerance to stresses Genetic enhancement using molecular technologies has revolutionized plant breeding. Advances in genetics and genomics have greatly improved our understanding of structural and functional aspects of plant genomes. The use of molecular markers as a selection tool provides the potential for increasing the efficiency of breeding programs by reducing environmental variability, facilitating earlier selection, and reducing subsequent population sizes for field testing. Molecular markers facilitate efficient introgression of superior alleles from wild species into the breeding programs and enable the pyramiding of genes controlling quantitative traits. Thus, enhancing and accelerating the development of stress tolerant and higher yielding cultivars for farmers in developing countries. Molecular marker analysis of stress tolerance in vegetables is limited but efforts are underway to identify QTLs underlying tolerance to stresses. 10
Prioritizing Vegetable Research to Address Impact of Climate Change It is unlikely that a single method to overcome the effects of environmental stresses on vegetables will be found. A systems approach, where all available options are considered in an integrated manner, will be the most effective and ultimately the most sustainable, particularly for developing countries in the tropics under a variable climate. This holistic strategy will need global integration of efforts; the resulting synergies will produce impact more quickly than the individual institutions working in isolation could accomplish. For this to succeed, adequate and long-term funding is necessary, scientific results have to be delivered, best approaches utilized and effective methods sustained to deliver global public goods for impact. AVRDC - The World Vegetable Center, as the world's leading international center focused on vegetable research and development, has expanded its research to further address the potential challenges posed by climate change. The Center's success in its major objectives of reducing malnutrition and alleviating poverty in developing countries through improved production and consumption of safe vegetables will involve adaptation of current vegetable systems to the potential impact of climate change. Vegetable germplasm with tolerance to drought, high temperatures and other environmental stresses, and ability to maintain yield in marginal soils must be identified to serve as sources of these traits for both public and private vegetable breeding programs. This germplasm will include both cultivated and wild accessions possessing genetic variation unavailable in current, widelygrown cultivars. Genetic populations are being developed to introgress and identify genes conferring tolerance to stresses and at the same time generate tools for gene isolation, characterization, and genetic engineering. Furthermore, agronomic practices that conserve water and protect vegetable crops from sub-optimal environmental conditions must be continuously enhanced and made easily accessible to farmers in the developing world. Finally, capacity building and education are key components of a sustainable adaptation strategy to climate change. Enhancing adaptation of tropical production systems to changing climatic conditions is a huge undertaking. It requires the combined efforts of many national and international institutions and an effective and efficient strategy to be able to deliver technologies that can mitigate the effects of climate change on the diverse crops and production systems. The scientific information and technologies developed through these initiatives must be readily accessible, consolidated and utilized in a strategic way. This can only be achieved through collaboration, complementarily, and coordinated objectives to address the consequences of climate change on the world's crop production. 11
References Abdalla AA, Verderk K (1968) Growth, flowering and fruit set of tomato at high temperature. The Neth J Agric Sci 16:71-76. AVRDC (1990) Vegetable Production Training Manual. Asian Vegetable Research and Training Center. Shanhua, Tainan, 447 pp. AVRDC (1979) Annual Report. Asian Vegetable Research and Development Center. Shanhua, Taiwan. 173 pp. AVRDC (1981) Annual Report. Asian Vegetable Research and Development Center. Shanhua, Taiwan. 84 pp. AVRDC (2005) Annual Report. AVRDC – The World Vegetable Center. Shanhua, Taiwan.
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Challenges and Opportunities of Vegetable Cultivation under Changing Climate Scenario ML Bhardwaj Department of Vegetable Science Dr YS Parmar University of Horticulture and Forestry, Nauni-173 230 Solan
The world's farmers are challenged with growing abundant, safe and nutritious food for an increasing global population in the face of changing climate and pest pressures. To enable them to continue to produce food sustainably, they need to have broad access to appropriate innovations, as well as the knowledge and skills to make these new tools valuable on the farm. India produces 133.5 millions tones of vegetables from an area of 7.9 million hectares (NHB, 2010). According to statistics release by Ministry of Agriculture, there has been 13.5% increase in area and 13.4% increase in vegetable output during the period 1996 to 2010. India is the second largest producer of vegetables in the world, next to China. India's share of the world vegetable market is around 14%. India is endowed with quite a diverse climatic condition, which enables production of more than 50 indigenous and exotic vegetables. India ranks first in peas and cauliflower production and is the second largest producer of onion, brinjal and cabbage. In spite of all these achievements, per capita consumption of vegetables in India is very low against WHO standards (180 g/day/capita against 300 g/day capita recommended by FAO). Iron deficiency, anaemia is quite wide spread in our country, the prevalence varying from 45 per cent in adult males to 70 per cent or more in women and children. There is an urgent need for providing health security to our population by supplying nutrition through balanced diet. Vegetables are rich source of vitamins, carbohydrates, salts and proteins. With increased health awareness in the general public and changing dietary patterns, vegetables are now becoming an integral part of average household's daily meals. In addition, high population growth rate has also given rise to high demand in basic dietary vegetables. Increased health awareness, high population growth rate, changing dietary patterns of increasingly affluent middle class and availability of packaged vegetables, has therefore generated a year round high demand for vegetables in the country in general and in major city centres in particular. However, our farmers have yet not been able to in cash this opportunity and still follow traditional sowing and picking patterns. This results in highly volatile vegetable supply market wherein the market is flooded with seasonal vegetables irrespective of demand presence on one hand and very high priced vegetables in off-season on the
other. Lack of developed vegetable processing and storage facility robs our farmers from their due share of profit margins. In natural season local vegetables flood the markets substantially bringing down the prices. In the absence of storage infrastructure and vegetable processing industry in the country, off-season vegetables farming is the only viable option that can add value to the farmer produce. There is a huge demand for fresh vegetables in the local as well as international markets, which includes Europe, Middle East, and Far Eastern markets but due to their perishable nature it is difficult to export this commodity. The facility of growing off-season vegetables also allows for growing non-conventional varieties of vegetables, which are in high demand in the international market. Vegetables can be cultivated in off-season, with the induction of an artificial technique like greenhouse technology, in which temperature and moisture is controlled for specific growth of vegetables. The production of vegetables all around the year enables the growers to fully utilize their resources and supplement income from vegetable growing as compared to other normal agricultural crops. Hybrid seeds that provide higher yield can lead to lower unit cost. Higher prices can be obtained by producing the right crops, at the right times and of better quality. They may also depend on negotiating skills and targeting high price buyers. Since, the land holding of farmers is decreasing, there is a need to increase the productivity of available land, off-season vegetable farming is a measure through which we can attain higher profit margins from the crop. Challenges: Climate change poses significant challenges and negative impacts upon for the present vegetable production. There is mounting evidence that smallr farmers in developing countries are experiencing increased climate variability and climatic change include more extreme events like average means of temperature and precipitation which is clearly linked to increased greenhouse gas (GHG) emissions.
Extreme Weather High temperatures in summer
Physiological impact Reproductive (flower) development impaired Crop development and yield impaired Crop quality impaired
High temperatures in winter
Cold hardiness limited
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Crops affected Peas, Tomatoes, Seed Production Vegetable Brassicas, Tomatoes Tomatoes, Vegetable Brassicas Seed production
Global climate change especially erratic rainfall pattern and unpredictable high temperature spells will reduce the productivity of vegetable crops. Developing countries in the tropics will be affected very much. Latitudinal and altitudinal shifts in different agro ecological zones, land degradation, extreme geophysical events, reduced water availability, rise in sea level and salinization are postulated. Among vegetable crops, tomatoes are the most important vegetable crops worldwide and grown over 4 million hectare of land area. Tomato, cabbage, onion, hot pepper and egg plant are important in Asia. In Asia, yields are highest in the east because of temperate and sub-temperate climate and the productivity is lowest in the hot and humid low lands of South East Asia. The extreme climatic conditions will affect soil fertility and increase soil erosion. So, additional fertilizers application or improved nutrient efficiency of crop will be needed to harness the potential for enhanced crop growth due to increased atmosphere CO2. In the tropical areas, high temperature conditions are prevalent in the growing season and with the changing climate crops will be subjected to temperature stress. High temperature affects the photosynthetic functions of plants and cause irregularities in the epidermis and endothesium, lack of opening of the stromium and poor pollen formation especially in case of tomato. In pepper, high post-pollination inhibits fruit set. In tomato, overall productivity is reduced by high temperatures due to bud drop, abnormal flower development, poor pollen production, dehiscence and viability, ovule abortion, poor viability, reduced carbohydrate availability, other reproductive abnormalities and above all inhibition of photosynthesis. Unpredictable drought affects world food security and cause great famines. Insufficient use of water all over the world and inefficient distribution system in developing countries decrease water availability. High temperature in combination with low precipitation could reduce the irrigation water availability and increase the evapo-transpiration leading to severe crop water stress particularly in vegetables which contain more than 90% water and ultimately influences the yield and quality. Drought causes an increase in solute concentration in the soil environment leading to an osmotic flow of water out of the plant cells which subsequently leads to an increase of solute concentration in plant cells and so, finally lowers the water potential and disrupts membranes and cell processes such as photosynthesis. Salt stress in plants is reflected in loss of turgor, growth reduction, wilting, leaf curling and epinasty, leaf abscission, decrease photosynthesis, respiratory changes, loss of cellular integrity, tissue necrosis and ultimately death of plants. Sometimes, vegetable production is also affected by heavy rainfall especially crops like tomato. Flooding reduces the oxygen level in the root zone inhibiting aerobic processes. Generally, flooded tomato plants accumulated endogenous ethylene that causes damage to the plants. Low oxygen levels stimulate an increased of an ethylene 15
precursor, 1-aminocyclopropane-1-carboxlic acid in the roots. In combination with high temperatures, flooding causes rapid wilting and death of plants. Yield potential of majority of vegetable crops is affected by various climatic factors like temperature, solar radiations, humidity, rainfall, wind, drought, salinity etc Causes of climate change · Deforestation · Fossil fuel consumption · Urbanisation · Land reclamation · Agricultural intensification · Freshwater extraction · Fisheries overexploitation · Waste production
(Ericksen, 2008)
Opportunities of vegetable production India is endowed with a wide range of agro-climatic conditions from tropical to temperate which makes it ideal for off-season vegetable production throughout the year. The hill states offer most congenial climatic conditions for off-season vegetable production during summer months for vegetables like tomato, capsicum, peas, beans, cole crops, root crops and cucumber. The main season vegetables of these hilly regions become off-season in the plains as result growers fetch lucrative returns from their produce. Off-season vegetables produced in the hills have a special significance because of specific flavour, aroma, freshness, prolonged self-life and keeping quality. These being environment specific are primarily confined to hilly areas of the country. The increase in area and production under off season vegetables in the last 3-4 decades may be because of increase in income level of consumers, change in dietary habit inclusion of more vegetables in food menu, urbanization, awareness of both farmers and consumers etc. Moreover, there exists a scope for increasing the off-season exotic vegetable production for domestic and international markets. Further, off-season vegetable production helps to bridge the seasonal gap between demand and supply and provides more employment opportunities to marginal and small hilly farmers. In Himachal Pradesh, agriculture plays an important role in the economy of Himachal Pradesh as 67 per cent of the total population depends on agriculture for its livelihood. Only 11 per cent of the total geographical area is available for agriculture, out of which 80 per cent is rain-fed and the holdings are small and scattered. Despite all these barring factors, climate of the state, especially in the hilly regions, is congenial for the cultivation of many off-season vegetables, horticultural and floricultural crops. In the valley areas of the district Kullu, the acreage of cereal crops 16
has declined from 59 per cent to 5 per cent but has been recompensed by vegetable crops over a period from 1990-91 to 2002-03 (Bala and Sharma, 2005). Farmers have tapped underground water sources through bore wells, tube-wells and hand pumps, to meet their water requirement. In the state, several vegetables grown in the summer- kharif season are harvested at a time when they can't be produced in the plains. These off-season vegetables have a definite market advantage and provide assured better returns to the farmers. The valley areas of the state have become famous for the production of quality peas, cabbage, cauliflower, French bean and capsicum. Also, being shortduration crops, 3-4 crops of vegetables can be taken by the farmers in the mid-hills per annum to augment their income. According to Thakur (1994) “Off-season vegetable production and marketing is the most profitable farm business giving very high production and income to farmers per unit area of land”. A system approach will thus be the most effective and sustainable for the developing countries in the tropics under a variable climate which will cover collection and improvement of wild species tolerance to drought, high temperature and other environment stresses using gene isolation, characterization and genetic engineering, stresses on effective delivery methodology to transfer technologies and disseminate knowledge and strategies on capacity building and education Conclusions · Climate change will lead to more periods of high temperature and periods of heavy rain. · Unseasonal or extreme weather will have an increasing impact on crop production. · There are already examples of what to expect. · Modelling can help predict consequences and guide adaptation. · Development of production system, improved varieties with improved water use efficiency. · Screening and validation of the cloned genes in model crops such as tomato. · Patenting elite genes and promoters · In India, diverse climatic conditions, available across the country provide ample opportunity to grow almost all types of vegetable crops, thus making our country the second largest producer of vegetables. 0 · An average increase of 1 C could affect the phenology of crop by influencing degree-day. Understanding, the likely impact of increase in temperature and CO2 on vegetable crops is the first step in developing sound adaptation strategies to address the adverse impact of climate change. 17
References: Arya Prem Singh. 2000. Off-season vegetable growing in hills. APH Publishing Corporation, New Delhi. 427p. Bala Brij, Sharma Nikhil and Sharma R K. 2011. Cost and return structure for the promising enterprise of off-season vegetables in Himachal Pradesh. Agricultural Economics Research Review 24: 141-148. De L C and Bhattacharjee S K. 2011. Handboook of vegetable crops. Pointer Publishers; Jaipur. pp. 27-31. Ericksen P. 2008. Climate Change and Food Security. Environmental Change Institute University of Oxford. UK. Ghosh S P. 2012. Carrying Capacity Of Indian Agriculture. Current Science. 102 (6): 889-893. IPCC. 2001. Climate change 2001: Impacts, adaptation and vulnerability. Intergovermental Panel on Climate Change. New York, USA. Liliana H. 2011. The Impacts of Climate Change on Food Production; A 2020 Perspective. United Nations Framework Convention on Climate Change. ISBN; USA. Mishra G P, Singh Narendra, Kumar Hitesh and Singh Shashi Bala. 2010. Protected Cultivation for Food and Nutritional Security at Ladakh. Defence Science Journal 61 (2): 219-225.
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High Altitude Protected Vegetable Production Brahma Singh Advisor, World Noni Research Foundation, Chennai Former Director, Life Sciences, DRDO, New Delhi
The topic has two major aspects. First one is high altitudes meaning inhabited areas 7000 feet above mean sea level. High altitudes are known for difficult environment from vegetable production point of view. The second one is protected vegetable production meaning vegetable production using protected agriculture technologies where ever necessitated. Both the aspects require brief elaboration before describing details of the topic. HIGH ALTITUDES In Indian Himalaya, high altitudes are of two types from their climate point of view. First one is cold and humid high altitudes spread over mainly in Uttaranchal, Sikkim, West Bengal and Arunachal Pradesh and other North East States. The other one is cold arid high altitudes mainly spread over in Jammu and Kashmir-the Ladakh region and Himachal Pradesh-Lahual-Spiti and Kinnaur area. Himachal Pradesh and Jammu and Kashmir have sizeable area under cold humid high altitudes also. The climatic conditions in cold humid and cold arid high altitudes are different necessitating different type of protected agriculture. Altitudes in Indian Himalayas range between 200 to more than 5000 meter above mean sea level. Winters in high altitudes are severe and prolonged restricting vegetable production season from 7 to 2.5 months or less as given below. Table -1. Vegetable production period at different altitudes
Altitude met ers above mean sea level 2670 3000 3300 4000
Period April-October May-Mid October Mid May –Mid September Mid June –August
Month 7.0 5.5 4.0 2.5
Sub-zero temperatures result in snowfall in higher altitudes. It could result in dry cold or wet along with rainfall or snow. In Ladakh and Lahaul-Spiti cold arid desert permafrost occurs with frozen upper soil (mostly sandy). In these areas ambient minimum temperatures are below or near freezing for almost five months. The relative humidity during this period is in the range of 45-60%. In Leh valley average minimum temperature from November to April is sub-zero and can be as low as minus 16 ? C. Wind velocity in the afternoon is very high resulting in dust storm or snow blizzards. The authors had an opportunity to work in these areas for more than a decade. This article is based mainly on their experience on cold desert. PROTECTED VEGETABLE PRODUCTION th
The area under greenhouse cultivation, reported by the end of 20 century was about 110 ha. in India and world over 275,000 hectare (Mishra, et al 2010). During last decade this area must have increased by 10 per cent if not more. In Europe, Spain is leading in protected agriculture with 51,000 ha mostly under low cost poly houses. In Asia, China has the largest area under protected cultivation, 2.5 M ha under poly house/greenhouse. Protected vegetable production is important component of protected agriculture. Protected vegetable production is practiced throughout the world irrespective of altitude of the place since several hundred years. River bed production of early cucurbits prevalent in India since ages , is protected agriculture. It involves protection of production stages of vegetables mainly from adverse environmental conditions such as temperature, hail, scorching sun, heavy rains, snow etc. In fact the need to protect the crops against unfavorable environmental conditions led to the development of protected agriculture. This is now becoming important due to climate change. Greenhouse is the most practical method of achieving the objectives of protected agriculture, where natural environment is modified by using sound engineering principles to achieve optimum plant growth and yield. Besides protected technology has potential to produce more produce per unit area with increased input use efficiency. There is need to increase nutritionally rich vegetable production and productivity of seasonal and non-season crops in our country. Research results have shown that by adopting protected cultivation productivity of vegetable crops can be increased by 3 to 5 times as compared to open environment. This aspect needs to be extensively exploited in India as has been done elsewhere in the world. To promote this Indo-Israel protected vegetable production projects in the country are serving the purpose. NAIP program of ICAR is giving due importance to this aspects besides different public and private organizations. Areas having uncongenial environment for vegetable production can also be converted into potential vegetable production centers with the help of protected agriculture technologies and techniques as has been discussed in this article. Needless to emphasize that better quality produce is obtained under protected conditions. 20
ADVANTAGES OF PROTECTED VEGETABLE CULTIVATION Protected vegetable production can reduce the amount of water and chemicals used in production of high value vegetables compared to open field conditions. The comparative advantages are: 1. Vegetables can be produced year round regardless of season. Adverse climate for production of vegetables can be overcome by different systems of protected production. 2. Multiple cropping on the same piece of land is possible. 3. Off season production of vegetables to get better return to growers is feasible. 4. It allows production of high quality and healthy seedlings of vegetables for transplanting in open field supporting early crop, strong and resistant crop stands. 5. Protective structures provide protection to high value crops from unfavorable weather conditions, pests and diseases. 6. Use of protected vegetable cultivation can increase production by more than five folds and increase productivity per unit of land, water, energy and labour. 7. Protected cultivation supports the production of high quality and clean products. 8. It makes cultivation of vegetables possible in areas where it is not possible in open conditions such as high altitudes deserts. 9. It makes vertical cultivation of vegetables possible using technologies like hydroponics, aeroponics etc and use of vertical beds for production. 10. Disease free seed production of costly vegetables becomes easy under protected structures. LIMITATIONS 1. Manual or hand pollination in cross pollinated vegetables like cucurbits or development of their parthenocarpic hybrids/varieties. 2. Expensive, short life and non-availability of cladding materials. 3. Lack of appropriate tools and machinery. 4. Structure cost initially looks unaffordable. Farmers with zero risk affordability do not come forward to adopt it. 5. Inadequate support from planners and scientists- suitable varieties/hybrids 21
and their production packages for protected production systems are either not available or very few. Protected structures in use are not scientifically designed; hence potentials of structure are not fully exploited. METHODS OF PROTECTED VEGETABLE PRODUCTION IN HIGH ALTITUDES The major protected cultivation methods at high altitudes of India in vogue are use of: 1. Poly houses/Greenhouse/net house/shade house 2. Low tunnels/row Covers 3. Plastic Mulching POLYHOUSES/GREENHOUSES/NETHOUSES/SHADEHOUSES Poly house/greenhouse is a framed structure having 200 micron (800 gauges) UV stabilized transparent or translucent low density polyethylene or other claddings which create greenhouse effect making microclimate favorable for plant growth and development. Structure is large enough to permit a person to work inside. The structure can be made in different shape and size using locally available materials or steel or aluminum or bricks or their combinations for its frame. In Ladakh poly houses are made above ground ( poly house), underground (soil trench) and a combination of two (polyench). Above ground poly houses are generally made of mud wall or unbaked brick wall on three sides. North side wall is made 7 feet high, east and west side walls are made with gradual slope to south having entrance on either side. Southern side is covered with polyethylene supported on locally available willow or poplar wood frames. Water for irrigation is stored inside but underground for convenience. The underground trench type poly house is made with suitable dimensions, generally 5-10x3-4x 1m with polyethylene cladding supported on wooden poles or GI pipes. A combination of both-construction of poly house above trench, known as polyench is being found better than both in winter months for production of vegetables where soil and sun heat is harnessed for maintaining required higher temperature inside. Polyench can be single or double walled. Poly houses are constructed using GI pipe of 25-75 mm diameter with a wall thickness of 2mm. These structures are fastened by welding, nuts and bolts or 22
clamped. Foundation for posts, size of hoops and perlins are worked out on engineering principles. Good cladding material (low density polyethylene, diffused or relatively translucent films, cross laminated, anti-fog, anti-drip, anti-sulphur types, fiber reinforced plastics, polycarbonates etc) is essential to ensure good life of greenhouse. Poly carbonate and FRP cladding green houses have also been found useful for covering large area.. During winter month solar heat is harnessed for production of leafy and other vegetables and vegetable nursery. The temperatures inside different protected structures during winter are higher than open field to the extent of supporting plant life. Insect proof net and shading materials are used to keep insects at bay and to lower temperatures in summer if considered necessary. Net and shade houses are used for vegetable production as protected structures elsewhere in lower altitudes in the country. LOW TUNNELS OR ROW COVERS Transparent plastic films or nets are stretched over low (1m or so) hoops made of steel wires, bamboo or willow twigs or cane or any other locally available suitable material to cover rows of plants in the field providing protection against unfavorable environment like low temperature, frost, wind, insect-pests etc. Different types of claddings are available in the market. Low tunnels with plastic mulch and drip irrigation are becoming popular for several vegetable crops production. PLASTIC MULCHING Mulching is a practice of covering soil around plants which makes growing conditions more favorable by conserving soil moisture, maintaining higher soil temperature, preventing weeds and allowing soil micro flora to be favorably active. In other areas organic mulches such as leaves, bark, peat, wooden chips, straw etc are used but in high altitudes particularly in arid high altitudes plastic is used for mulching which has unimaginably significantly contributed to vegetable production there. Plastic mulching is one of the widely used practices in protected agriculture particularly in vegetable production. It has following advantages: 1. It conserves soil moisture by preventing water evaporation from it. 2. It prevents germination of annual weeds because of its opaqueness. 3. Plastic mulches maintain a warm temperature during night which facilitates an early establishment of seedlings by strong root system or germination of seeds. 23
4. Soil water erosiopn is minimized. 5. Plastic mulches serve for longer period. They can be used for more than one season. 6. Provides cleaner crop produce. 7. More income through early, higher and quality yields. CONTRIBUTION OF PROTECTED CULTIVATION ON ARID HIGH ALTITUDE VEGETABLE PRODUCTION Arid high altitudes of Ladakh and Lahaul and Spiti in early sixties used to grow root vegetables like radish, turnip, carrot, beet root; potato and mongol palak (beet leaf). After Chinese aggression (1962), induction of Indian defence forces in these areas necessitated local production of different vegetables. Defence Research and Development Organization (DRDO) through its laboratory, Field Research Laboratory now Defence Institute of High Altitude Research, Leh did pioneering research. With the help of protected agriculture technologies it could have been possible to grow now all short of vegetables there during agriculture season (May to September or mid October). Perhaps first glass house in high altitudes of the country was erected in Leh (11500 ft amsl) in 1964. Some of the major contributions made by DRDO in developing protected vegetable production technologies are as follows: 1.Protected vegetable nursery production making cultivation of several vegetables possible Early production of vegetable nursery under different protected structures during March and April ( minimum atmospheric temperature is sub-zero) and transplanting them in May and June with and without plastic mulch extended agriculture period and made possible cultivation of cabbage, cauliflower, knoll-khol, broccoli, brussel's sprouts, tomato, brinjal, chili, capsicum and onion possible. Use of plastic mulch enabled early, quality and higher yield of these vegetables. In mulched crop low pressure (gravity/slope) drip irrigation and fertigation is possible as experimented by DRDO. In this way most of the vegetables are being grown on large scale making the area surplus in cabbage, something unbelievable. Early and late production of vegetables with the help of protected technology has also been standardized which extends availability period of locally produced vegetables-an important aspect there. 2. Making Cucurbits production possible in cold desert Till early 1990s cucurbits cultivation in open in Ladakh was considered impossible. But growing seedlings in poly pouch under poly houses during April24
May and transplanting them in open field with plastic mulch made it possible to grow almost all cucurbits in Leh. This has not only improved vegetable basket in the area but also added variety to food basket of local inhabitants and soldiers. Commercial production of cucurbits in cold desert of India is now possible through protected cultivation. Sarda melon imported in large quantity in the country can be produced in these areas with ease. Production of off season (August and September) muskmelon, watermelon etc in open fields has also become possible. An early crop of cucurbits like squash, longmelon etc is also taken in poly houses. 3. Sub-zero atmosphere vegetable production As stated earlier during winter these areas remain cut off with main land due to heavy snow fall. Only air communication is on during winter months. Through air transportation of bulky and perishable commodities like vegetables is not only expensive but very difficult. In Ladakh sector Army alone spends several crores of rupees only on transportation of vegetables. Cost of transportation is more than the cost of vegetables. Hence local production through protected cultivation is being successfully promoted there. This is being encouraged by harnessing solar energy both thermal and photovoltaic and making heating of greenhouses possible. The geothermal energy sources available in the area are potential source of heating greenhouses. Remoteness of these sources is coming in the way of their exploitation 4. Vegetable Seed production Seed production of biennial crops like temperate varieties of cole crops, root crops, and onion used to take two years or 18 months in these areas. First year normal crop is grown and stored underground during long winters. Second year in summer they are planted for seed production. By the protected agriculture technology now it has become possible to produce seeds of these varieties in half the time by raising early crop under protected structure and transplanting them in open fields for seed production. Pusa Himani radish, long day onions, Nantes carrot and others respond well to this technique. Production of seeds of temperate varieties of vegetables in India is a problem due to lack of consorted research and development efforts? Future Prospects To ensure nutritional security along with food security to the ever growing population of the country it is essential to double production of vegetable crops in the country. Major constraint is increased pressure on cultivable lands near metros where vegetables are generally grown. This is due to urbanization and industrialization which is also essential. Therefore, it is at most necessary to improve the productivity of vegetables adopting protected cultivation in the country in general and high altitudes in particular.
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Protected cultivation of vegetables in high altitudes of Himalaya has been practiced successfully indicating its potential to deal with conditions created by climate change scenario in the country. Protection against adverse climatic conditions for plant growth has become universal necessity. Protection of plant growth and development against adverse physical (temperature, rain and wind and biological (insects and diseases) factors through protected agriculture technologies is going to be uncommon in near future because of climate change and advantages of protected cultivation. There is need to develop area specific, most appropriate, efficient and affordable protected structures with cheaper and durable cladding materials. Emphasis would be shifted on development of suitable varieties and hybrids of vegetables for protected cultivation under organic and inorganic production protocols. Vegetable nurseries would be produced under protected structures both at individual farmer and commercial nurseries level. Tools and machinery for protected cultivation would be developed and become common. Vertical or multitier farming of vegetables would be developed to make use of protected space. High altitudes are likely to be harnessed for large scale vegetable production under protected structures. Human resource development on protected agriculture and Government support for its promotion should be taken up through State Agriculture Universities and department of horticulture. Plastic mulching coupled with drip irrigation in vegetable production is going to be a common practice because their proven advantages. There is emphasis on development of suitable varieties of vegetables which have high production and productivity under protected conditions in high altitudes and other places. Production protocols of particular variety of a vegetable like cucumber, capsicum and tomato are being developed for different structures in different climates and conditions. Summary High altitudes in India are reasonably populated with local tribes and troops. Vegetable production for them during winter months when environment mainly temperature is unfavorable for their growth, has been discussed. Protected production technologies or green house technologies developed for these areas such as use of local poly house, both underground and above ground along with combination of both have been discussed. Production of leafy vegetables under subzero atmosphere, cucurbits and almost all vegetables in cold arid high altitudes of Ladakh using protected agriculture technology has been mentioned in brief. Production of almost all vegetable crops during limited agriculture season from May to September in cold desert of Ladakh, considered remote possibility has now become possible with the help of protected agriculture technologies. Future prospects of protected cultivation of vegetable crops in high altitudes and elsewhere have been highlighted. 26
References: Dhaulakhandi, A. B. and Singh, B. (1999) Winter performance of greenhouse attached passive solar heated hut at high altitude. SESI, Journal 9(2):105-114. Mishra, G. P., Singh, N. and Kumar,H. and Singh, S. B. (2010) Protected Cultivation for Food and Nutritional Security at Ladakh Defence Science Journal, Vol. 61, No. 2, March 2010, pp. 219-225 NAAS 2010. “Protected Agriculture in North-West Himalayas”. Policy Paper No. 47, National Academy of Agricultural Sciences, New Delhi. pp16. Singh, B. (1995) Vegetable Production in Ladakh. Field Research Laboratory, Leh. India Singh, B. and Dhaulakhandi, A. B. (1998). Application of solar greenhouse for vegetable production in cold desert in renewable energy. Energy Efficiency Policy and the Environment. Elsevier Science Ltd, UK, P2511-314 Singh, B., Dwivedi, S K. and Chaurasia, O.P.(2004). Improvement in production and productivity of horticultural crops in cold arid regions of India. Proceedings of the first Indian Horticulture Congress, 6-9 November, 2004, The Horticultural Society of India, New Delhi, India, viii+ 764p Singh, B., Dwivedi, S. K. and Plajor, E. (2000). Studies on suitability of various structures for winter vegetable production at sub-zero temperatures. Acta Hort., 517:309-14. Singh, B., Dwivedi, S. K. and Sharma J. P. (2000). Greenhouse technology for winter vegetable cultivation in cold arid zones. In: Dynamics of cold arid Agriculture (Eds J. P. Sharma and A. A. Mir) Kalayani Publishers, Judhiana. PP 279-293. Singh, B., Dwivedi, S.K., Singh, N. and Paljor, E. (1999). Sustainable Horticulture practices for cold arid areas. In : The Himalayan Environment. eds. SK Dash & J Bahadur . New age International (P) Ltd, Publishers – New Delhi. pp 235 – 245. Singh, B. and Dwivedi, S. K. (2002). Vegetable production potential in Ladakh. In: Vegetable growing in India. Eds. P. S. Arya and Sant Prakash. Kalyani Publishers, New Delhi. pp 87-93. Singh, B., Dwivedi, SK. and Sharma, JP. (2000 a). Greenhouse technology for winter vegetable cultivation in cold arid zones. In: dynamics of cold arid agriculture. Eds. J.P. sharma and A.A. Mir, kalyani publishers-Ludhiana, pp. 279-293. Singh,B. (1999) Vegetable production in cold desert of India: a success story on solar greenhouses. Acta horticulture 534: 205-12. 27
Singh, N. and Singh, B. ( 2003). Ladakh mein sabji utpadan (Vegetable Production in Ladakh. Field Research Laboratory, Leh.pp 139 Singh, B. and Singh, N (2011) High altitudes protected cultivation of vegetables. Seminar on protected cultivation at GB Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, Uttarakhand.
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Protected Cultivation of Vegetables in Indian Plains Mathura Rai Former Director, Indian institute of Vegetable Research Varanasi 1/36 Rashmikhand, Shardanagar, Lucknow-226 002, UP
Vegetable growers can substantially increase their income by cultivation of vegetables under protected condition during off-season as the vegetables produced during their normal season generally do not fetch good returns due to availability of these vegetable in the markets. Off-season cultivation of cucurbits under low plastic tunnels is one of the most profitable technologies under northern plains of India. Walk-in tunnels are also suitable and effective to raise off-season nursery and offseason vegetable cultivation due to their low initial cost. Insect proof net houses provides virus free ideal conditions for productions of tomato, chilli, sweet pepper and other vegetables mainly during the rainy season. These low cost structures are also suitable for growing pesticide-free green vegetables. Low cost greenhouses can be used for high quality vegetable cultivation for long duration (6-10 months) mainly in peri-urban areas of the country. Polytrenches have also been proved extremely useful for growing vegetables under cold desert conditions in upper Himalayas in the country. Poly house/ Greenhouses are frames of inflated structure covered with a transparent material in which crops are grown under controlled environment conditions. Greenhouse cultivation as well as other modes of controlled environment cultivation has been evolved to create favorable micro-climates, which favors the crop production could be possible all through the year or part of the year as required. The primary environmental parameter traditionally controlled is temperature, usually providing heat to overcome extreme cold conditions. However, environmental control can also include cooling to mitigate excessive temperatures, light control either shading or adding supplemental light, carbon dioxide levels, relative humidity, water, plant nutrients and pest control. Status of Greenhouse Cultivation Commercial greenhouses with climate controlled devices are very few in the country. Solar greenhouses comprising of glass and polyethylene houses are becoming increasingly popular both in temperate and tropical regions. In early sixties, Field Research Laboratory (FRL) of DRDO at Leh attempted solar greenhouse vegetable production research and made an outstanding contribution to the extent that almost every rural family in Leh valley possesses a polyhouse these days. Indian Petro Chemical Corporation Ltd (IPCL) boosted the greenhouse
research and application for raising vegetables by providing Ultra Violet (UV) stabilized cladding film and Aluminium polyhouse structures. Several private seed production agencies have promoted greenhouse production of vegetables. In comparison to other countries, India has very little area under greenhouses. Classification of greenhouse based on suitability and cost a) Low cost or low tech greenhouse Low cost greenhouse is a simple structure constructed with locally available materials such as bamboo, timber stone pillars, etc. The ultra violet (UV) film is used as cladding materials. Unlike conventional or hi-tech greenhouses, no specific control device for regulating environmental parameters in-side the greenhouse are provided. Simple techniques are, however, adopted for management of the temperature and humidity. Even light intensity can be reduced by incorporating shading materials like nets. The temperature can be reduced during summer by opening the side walls. Such structure is used as rain shelter as well as to protect from low temperature for crop cultivation. Otherwise, inside temperature is increased when all sidewalls are covered with plastic film. This type of greenhouse is mainly suitable for cold climatic zone. b) Medium-tech greenhouse Greenhouse users prefers to have manually or semiautomatic control arrangement owing to minimum investment. This type of greenhouse is constructed using galvanized iron (G.I) pipes. The canopy cover is attached with structure with the help of screws. Whole structure is firmly fixed with the ground to withstand the disturbance against wind. Exhaust fans with thermostat are provided to control the temperature. Evaporative cooling pads and misting arrangements are also made to maintain a favourable humidity inside the greenhouse. As these system are semiautomatic, hence, require a lot of attention and care, and it is very difficult and cumbersome to maintain uniform environment throughout the cropping period. These greenhouses are suitable for dry and composite climatic zones. c) Hi-tech greenhouse To overcome some of the difficulties in medium-tech greenhouse, a hi-tech greenhouse where the entire device, controlling the environment parameters, are supported to function automatically. At present computer based advance technology with full automaton for temperature, humidity, irrigation control is available which can be utilized for high value low volume vegetable for local consumption and long distance supply. Shade house Shade houses are used for the production of plants in warm climates or during summer months. Nurserymen use these structures for the growth of hydrangeas and 30
azaleas during the summer months. Apart from nursery, flowers and foliages which require shade can also be grown in shade houses. E.g. Orchids, These shade structures make excellent holding areas for field-grown stock while it is being prepared for shipping to retail outlets. Shade houses are most often constructed as a pole-supported structure and covered with either lath (lath houses) or polypropylene shade fabric. Polypropylene shade nets with various percentages of ventilations are used. Black, green, and white colored nets are used, while black colours are the most preferred as it retains heat outside. Heating of Polyhouse Heating is required in winter season. Generally, the solar energy is sufficient to maintain inner temperature of polyhouse but some times more temperature is required to be supplied to some crops. For this few methods are as follows: i. Constructing a tunnel below the earth of poly house. ii. Covering the northern wall of the house by jute clothing. iii. Covering whole of the polyhouse with jute cloth during night iv. Fitting solar energy driven device in polyhouse. Cooling of Polyhouse In summer season, when ambient temperature rises above 400C during day time the cooling of polyhouse is required by the following measures, not only the temperature but also relative humidity of polyhouse can also be kept within limit. i. Removing the internal air or polyhouse out of it in a natural manner. ii. Changing the internal air into external air by putting the fan on. iii. Installation of cooler on eastern or Western Wall not only keeps temperature low but maintains proper humidity also. iv. Running water-misting machine can control the temperature of the polyhouse Cladding material Polythene proves to be an economical cladding material. Now long lasting, unbreakable and light roofing panels-UV stabilized clear fiber glass and polycarbonate panels are available. Plastics are used in tropical and sub-tropical areas compared to glass/fiberglass owing to their economical feasibility. Plastics create enclosed ecosystems for plant growth. LDPE (low density polyethylene) / LLDPE (linear low density polyethylene) will last for 3-4 years compared to polythene without UV stabilizers. 31
Plant growing structures / containers in greenhouse production The duration of crop in greenhouse is the key to make the greenhouse technology profitable or the duration of production in greenhouses should be short. In this context, use of containers in greenhouse production assumes greater significance. The containers are used for the following activities in greenhouse production Advantages of containers in greenhouse production Increase in production capacity by reducing crop time. High quality of the greenhouse product Uniformity in plant growth with good vigor Provide quick take off with little or no transplanting shock. Easy maintenance of sanitation in greenhouse Easy to handle, grade and shift or for transportation Better water drainage and aeration in pot media. Easy to monitor chemical characteristics and plant nutrition with advance irrigation systems like drips. Drip irrigation and fertigation systems in greenhouse cultivation The plant is required to take up very large amounts of water and nutrients, with a relatively small root system, and manufacture photosynthates for a large amount of flower per unit area with a foliar system relatively small in relation to required production. Watering system Micro irrigation system is the best for watering plants in a greenhouse. Micro sprinklers or drip irrigation equipments can be used. Basically the watering system should ensure that water does not fall on the leaves or flowers as it leads to disease and scorching problems. In micro sprinkler system, water under high pressure is forced through nozzles arranged on a supporting stand at about 1 feet height. This facilitates watering at the base level of the plants. Equipments required for drip irrigation system include i) A pump unit to generate 2.8kg/cm2 pressure i) Water filtration system – sand/silica/screen filters iii) PVC tubing with dripper or emitters Drippers of different types are available i) Labyrinth drippers 32
ii) Turbo drippers iii) Pressure compensating drippers – contain silicon membrane which assures uniform flow rate for years iv) Button drippers- easy and simple to clean. These are good for pots, orchards and are available with side outlet/top outlet or micro tube out let v) Pot drippers – cones with long tube Water output in drippers a. 16mm dripper at 2.8kg/cm2 pressure gives 2.65 liters/hour (LPH). b. 15mm dripper at 1 kg/cm2 pressure gives 1 to 4 liters per hour Filters: Depending upon the type of water, different kinds of filters can be used. Gravel filter: Used for filtration of water obtained for open canals and reservoirs that are contaminated by organic impurities, algae etc. The filtering is done by beds of basalt or quartz. Hydrocyclone: Used to filter well or river water that carries sand particles. Disc flitersL: Used to remove fine particles suspended in water Screen filters: Stainless steel screen of 120 mesh ( 0.13mm) size. This is used for second stage filtration of irrigation water. Fertigation system In fertigation system, an automatic mixing and dispensing unit is installed which consists of three systems pump and a supplying device. The fertilizers are dissolved separately in tanks and are mixed in a given ratio and supplied to the plants through drippers. Fertilizers: Fertilizer dosage has to be dependent on growing media. Soilless mixes have lower nutrient holding capacity and therefore require more frequent fertilizer application. Essential elements are at their maximum availability in the pH range of 5.5 to 6.5. In general Micro elements are more readily available at lower pH ranges, while macro elements are more readily available at pH 6 and higher. Forms of inorganic fertilizers: Dry fertilizers, slow release fertilizer and liquid fertilizer are commonly used in green houses. Slow release fertilizer: They release the nutrient into the medium over a period of several months. These fertilizer granules are coated with porous plastic. When the granules become moistened the fertilizer inside is released slowly into the root medium. An important thing to be kept in mind regarding these fertilizers is that, they should never be added to the soil media before steaming or heating of media. Heating melts the plastic coating and releases all the fertilizer into the root medium at once. The high acidity would burn the root zone. 33
Liquid fertilizer: These are 100 per cent water soluble. These comes in powdered form. This can be either single nutrient or complete fertilizer. They have to be dissolved in warm water to desired concentration. Fertilizer application methods: 1. Constant feed: sLow concentration at every irrigation are much better. This provides continuous supply of nutrient to plant growth and results in steady growth of the plant. Fertilization with each watering is referred as fertigation. 2. Intermittent application: Liquid fertilizer is applied in regular intervals of weekly, biweekly or even monthly. The problem with this is wide variability in the availability of fertilizer in the root zone. At the time of application, high concentration of fertilizer will be available in the root zone and the plant immediately starts absorbing it. By the time next application is made there will be less availability of nutrient. This fluctuation results in uneven plant growth rates, even stress and poor quality crop. Fertilizer injectors This device inject small amount of concentrated liquid fertilizer directly into the water lines so that green house crops are fertilized with every watering. Multiple injectors Multiple injectors are necessary when incompatible fertilizers are to be used for fertigation. Incompatible fertilizers when mixed together as concentrates form solid precipitates. This would change nutrient content of the stock solution and also would clog the siphon tube and injector. Multiple injectors would avoid this problem. These injectors can be of computer controlled H.E. ANDERSON is one of the popular multiple injector. Fertilizer Injectors Fertilizer injectors are of two basic types: Those that inject concentrated fertilizer into water lines on the basis of the venturi principle and those that inject using positive displacement A. Venturi Principle Injectors 1. Basically these injectors work by means of a pressure difference between the irrigation line and the fertilizer stock tank. a) The most common example of this is the HOZON proportioner. b) Low pressure, or a suction, is created at the faucet connection of the Hozon at the suction tube opening. This draws up the fertilizer from the stock tank and is blended in to the irrigation water flowing through the Hozon faucet connection. 34
c) The average ratio of Hozon proportioners is 1:16. However, Hozon proportioners are not very precise as the ratio can vary widely depending on the water pressure. d) These injectors are inexpensive and are suitable for small areas. Large amounts of fertilizer application would require huge stock tanks due to its narrow ratio. B. Positive displacement injectors: 1. These injectors are more expensive than Hozon types, but are very accurate in proportioning fertilizer into irrigation lines regardless of water pressure. 2. These injectors also have a much broader ratio with 1:100 and 1:200 ratio being the most common. Thus, stock tanks for large applications areas are of manageable size and these injectors have much larger flow rates. 3. Injection by these proportioners is controlled either by a water pump or an electrical pump. 4. Anderson injectors are very popular in the greenhouse industry with single and multiple head models. a. Ratios vary from 1:100 to 1:1000 by means of a dial on the pump head for feeding flexibility. b. Multihead installations permit feeding several fertilizers simultaneously without mixing. This is especially significant for fertilizers that are incompatible (forming precipitates, etc.) when mixed together in concentrated form. 5. Dosatron feature variable ratios (1:50 to 1:500) and a plain water bypass . 6. Plus injectors also feature variable ratios (1:50 to 1:1000) and operates on water pressure as low as 7 GPM. 7. Gewa injectors actually inject fertilizer into the irrigation lines by pressure. a. The fertilizer is contained in a rubber bag inside the metal tank.Water pressure forces the fertilizer out of the bag into the water supply. b. Care must be taken when filling the bags as they can tear. c. Ratios are variable from 1:15 to 1:300. 8. If your injector is installed directly in a water line, be sure to install a bypass around the injector so irrigations of plain water can be accomplished. Pinching Pinching operation should be done after one month of transplanting. In general, maintaining the two shoots per plant has been found effective. 35
Developing devices for monitoring through internet Control and monitoring of environmental parameters inside a Polyhouse farm, so as to ensure continuous maintenance of favorable crop atmosphere is very essentia. The concept encompasses data acquisition of thermal process parameters through a sensor network, data storage, post processing and online transmission of data to multiple users logged on to their respective web-browsers. Further, control of process parameters of a Polyhouse (for example, toggle on/off control of pumps and accessories, louvers and ventilators, air flow rate, sunlight management, etc.) from one or more remote monitoring stations over the web server in real time is also integrated. A graphical user interface (GUI) is unified for the ease of operations by the farming community. System also allows transmission of process parameters, including emergency alarm signals via e-mail client server or alternatively sending a SMS on a mobile phone. A conventional chat has also been integrated with the GUI to add vibrancy to inter-user communication. This feature can be embedded in upcoming 3G mobile technology. Simulations and video tutorials can also be integrated in the web server for teaching the farming community. Such integrated approach greatly widens the socio-economic possibilities for farmers through interaction with modern technological resources (Sonawane et al., 2008) References: Sonawane,Y. R. , Khandekar, S., Mishra , B.K. and Soundra Pandian, K. K. (2008). Environment Monitoring and Control of a Polyhouse Farm through Internet. World Bank: India Country Overview 2008 pp1-6 Wani, K.P. Pradeep Kumar Singh, Asima Amin*, Faheema Mushtaq and Zahoor Ahmad Dar (2011). Protected cultivation of tomato, capsicum and cucumber under Kashmir valley conditions Asian Journal of Science and Technology,1(4):056-061.
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Relevance of Conservation Agriculture under Climate Change RK Sharma Directorate of Wheat Research, Karnal – 132 001, Haryana, India
Agriculture in India was focused on achieving food security through increased area under high yielding varieties, expansion of irrigation and increased use of external inputs like chemical fertilisers and pesticides. With the unabated increase in population, more and more land will be required for urbanization, and productivity needs to be increased to meet the increasing domestic and industrial demand. A decline in land productivity has been observed over the past few years. Moreover, due to indiscriminate use, or rather misuse, of natural resources especially water has led to groundwater pollution as well as depletion of groundwater resources (Nayar and Gill 1994). Depleting soil organic carbon status, decreasing soil fertility and reduced factor productivity are other issues of concern (Yadav 1998). These evidences indicate the weakening of natural resource base. If we continue to exploit the natural resources at the current level, productivity and sustainability is bound to suffer. Therefore, to achieve sustainable higher productivity, efforts must be focussed on reversing the trend in natural resource degradation by adopting efficient resource conservation agriculture practices. Laser land levelling is a pre-requisite for enhancing the benefits of the resource conservation practices. Generally, fields are not properly levelled leading to poor performance of the crop, because, part of area suffers due to water stress and part due to excess of water. After laser levelling the field, it has been observed that yield enhances from 10 to 25 per cent. The higher yields are due to proper crop stand, uniform water distribution, crop growth and uniform maturity. In addition to higher yield, the savings of water, a scarce resource, is from 35-45 per cent due to higher application efficiency, increased nutrient use efficiency by 15-25 per cent, reduces weed problem and increases the cultivable area by 3 to 6 per cent due to reduction in area required for bunds and channels (Jat et al. 2004). Conservation agriculture Conservation agriculture is much more than just reducing the mechanical tillage. In a soil that is not tilled for many years, the crop residues remain on the soil surface and produce a layer of mulch. This layer protects the soil from the physical impact of rain and wind, conserves soil moisture, moderates soil temperature and harbours a number of organisms, from larger insects down to soil borne fungi and bacteria. These organisms help convert the crop residues into humus and contribute to the physical stabilization of the soil structure and buffering of water and nutrients.
Most tillage operations targeted at loosening the soil lead to mineralization and reduction of soil organic matter, a substrate for soil life. Thus, agriculture with reduced mechanical tillage is only possible when soil organisms are taking over the task of tilling the soil. This, however, leads to other implications regarding the use of chemical farm inputs. In a system with reduced mechanical tillage based on mulch cover and biological tillage, alternatives have to be developed to control pests and weeds. Therefore, “Integrated Pest Management” becomes mandatory. One important element to achieve this is crop rotation, interrupting the infection chain between subsequent crops. Synthetic chemical, particularly herbicides, are inevitable during initial years but have to be used with care to reduce the negative impacts on soil life. A new balance between pests and beneficial organisms, crops and weeds, gets established and the farmer learns to manage the cropping system with reduced use of synthetic pesticides and mineral fertilizer compared to "conventional" farming. Hence, “Conservation Agriculture” (CA) involves a complete change in the crop production system, although the entry point is reduction of mechanical soil tillage. It involves modifications in the machinery, which means more mechanisation, maintenance of surface residues providing at least 30% soil cover, minimum soil disturbance, adjustment, if required, in the cropping system, minimum and need based use of chemicals. Why seeding into crop residues? Burning of crop residues and ploughing of soil is mainly considered necessary phytosanitary measures controlling pests, diseases and weeds. Leaving crop residues on the soil surface seems to be a much better option than incorporation or burning as it reduces soil erosion and soil water evaporation, avoids short-term nutrient tie up, and suppresses weeds. Moreover, the slower decomposition also helps build up soil organic carbon (Unger 1991; Sharma et al. 2008). Tillage is mainly practised to prepare seedbed and to control already germinated weeds. But the tillage is also responsible for stimulation of the weed germination and emergence of many weeds by brief exposure to light (Ballard et al. 1992). Crop residues may influence the weed seed reserve in the soil directly or indirectly and also the efficiency of soil-applied herbicides (Crutchfield et al. 1986). Moreover, incorporated plant residues may release the allelochemicals, which can be toxic to weeds (Inderjit and Keating 1999). Residue retention on the soil surface in combination with no till system may also significantly contribute to the suppression of weeds (Chhokar et al. 2009). No till system reduce the weed emergence by avoiding exposure to light as well as offering mechanical impedance. Residue retention also influences soil temperature and soil moisture, which in turn may increase or decrease the weed germination depending on type of weed flora, soil 38
conditions, type of crop residue and quantity. At lower residue level, weed flora may be higher than the residue free conditions but at higher levels definitely the weed will be reduced considerably. Goal of CA Conservation Agriculture aims to conserve, improve and make more efficient use of natural (soil, water and biological) resources and external inputs and contributes to environmental conservation along with enhanced and sustained agricultural production. Characteristics of CA Conservation Agriculture maintains a permanent or semi-permanent organic soil cover. This can be a growing crop or the plant residues. Its function is to protect the soil physically from sun, rain and wind as well as to feed the soil biota. The soil micro-organisms and soil fauna takes over the tillage function and soil nutrient balancing. As the mechanical tillage disturbs this process, the zero or minimum tillage and direct seeding are important elements of CA. A varied crop rotation is also important to avoid disease and pest problems. Rather than incorporating biomass such as green manures, cover crops or crop residues, it is left on soil surface in CA. The dead biomass serves as physical protection and as substrate for the soil fauna. In this way mineralization is reduced and suitable soil levels of organic matter are built up and maintained. What is not CA? Zero-tillage: Zero tillage as stand alone is not Conservation Agriculture but is an important component of CA. Tillage is avoided in CA by forcing the seed with appropriate direct drills into the soil, by maintaining a soil cover. This also improves soil structure, facilitates direct planting and uses biological tillage. Nevertheless, zero tillage can be transition step towards CA. Conservation tillage: It is a practice to open the soil surface to increase rain water infiltration and reduce erosion. However, it still depends on tillage as the soil structure-forming element. Direct planting/seeding: This is only a technique that refers to seeding/planting without preparing a proper seedbed. The same equipment is used in Conservation Agriculture. However, the term direct seeding can also be used for implements, which combine primary and secondary tillage and seeding in one machine/tractor operation like the rotary till drills. Organic farming: Although it is based on natural processes, Conservation Agriculture is not a synonym of organic farming. CA does not prohibit the use of 39
chemical inputs. For example, herbicides are important component of Conservation Agriculture, particularly in the transition phase. However, in view of the importance of soil life, farm chemicals, including fertilizer, are carefully applied and over the years, quantities applied tend to decline. In some cases, organic farming can be practised within the CA framework. Is CA compatible with IPM? Conservation Agriculture is not only compatible but also actually works on IPM principles. CA, like IPM, enhances biological processes. It expands the IPM practices from crop and pest management to land husbandry. Without the use of IPM practices the build up of soil biota for the biological tillage would not be possible. What is the role of Animal Husbandry in CA? By recycling of nutrients, livestock production can be fully integrated into conservation agriculture. This reduces the environmental problems caused by concentrated intensive livestock production. Integration of livestock into agricultural production enables the farmer to introduce forage crops into the crop rotation thereby reducing pest problems. Forage crops can often be used as dualpurpose fodder and soil cover crops. However, in arid areas having low biomass production, the conflict between use of organic matter to feed the animals or to cover the soil is still to be resolved. What are the downsides of CA? During the transition phase, CA may require application of herbicides in case of heavy weed infestation and certain soil borne pests or pathogens might create new problems due to the change in biological equilibrium. Once the CA environment stabilizes, it tends to be more sustainable than conventional agriculture. Benefits of CA Conservation Agriculture attracts different people for different reasons. Farmers · Reduction in labour, time, farm power and thereby the production cost · Longer lifetime and less repair of tractors due to fewer passes and lower fuel consumption · More stable yields, particularly in dry years · Better trafficability in the field
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· Gradually increasing yields with decreasing inputs · Increased profit, in some cases from the beginning, in all cases after a few years. Communities/Environment/Watershed · More constant water flows in rivers, re-emergence of dried wells · Cleaner water due to less erosion · Less flooding due to increased water infiltration rate · Less impact of extreme climatic situations (hurricanes, drought etc.) · Lower cost for road and waterway maintenance · Better food security At global level · Carbon sequestration (greenhouse effect): the global potential of CA in carbon sequestration could equal the human made increase in CO2 in the atmosphere. · Less leaching of soil nutrients or chemicals into the ground water · Less pollution of the water · Practically no erosion (erosion is less than soil build up) · Recharge of aquifers through better infiltration · Lower fuel consumption for agriculture What are the issues? Despite its advantages, CA has spread relatively slowly for a number of reasons. Firstly, there is greater pressure to adopt in tropical, rather than temperate climates. Over the past 20 years the establishment of local knowledge base has ensured its spread. Converting to Conservation Agriculture needs higher management skills, the first years might be very difficult and might need moral support and perhaps even financial support to invest into new machinery like zero-tillage planters. As it requires a complete change of understanding, the scientific and technical sectors must focus on CA as the necessary technologies are often unavailable.
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Is Conservation Agriculture real? CA is being practised on more than 100 million ha, mostly in South and North America and its adoption is also growing exponentially on small to large farms in Europe as well as Asia. New Machines for CA The Double disc coulters and Punch planter/Star wheel are the machines being used in South and North America as well as in Europe, where large tractors and heavy machines are being used. The performance of smaller versions of these machines was not satisfactory in Asia. In India, two machines namely Turbo Happy seeder and Rotary Disk Drill (RDD) are developed/ improvised at PAU Ludhiana and DWR Karnal, respectively for seeding into surface retained residues after combine harvesting. Both these machines are based on the rotary till mechanism. Conclusions The conservation agriculture helps reduce or rather reverse the natural resource degradation by improving soil health and reducing ground water and environmental pollution. The soil moisture conservation and soil temperature moderation can help to a large extent in overcoming the adverse effects of climate change. References: Ballard CL, AL Scopel, RA Sánchez and SR Radosevich. 1992. Photomorphogenic processes in the agricultural environment. Photochemistry and Photobiology 56, 777-788. Chhokar RS, S Singh, RK Sharma and M Singh. 2009. Influence of straw management on Phalaris minor control. Indian J. Weed Sci. 41: 150-156. Crutchfield DA, GA Wicks and OC Burnside. 1986. Effect of winter wheat straw mulch level on weed control. Weed Science 34, 110-114. Inderjit and Keating K.I. 1999. Allelopathy: Principles, procedures, processes, and promises for biological control. Advances in Agronomy 67, 141-231. Jat, ML, SS Pal, AVM Subba Rao, Kuldeep Sirohi, SK Sharma and Raj K Gupta. 2004. Laser land levelling – the precursor technology for resource conservation in irrigated ecosystem of India. Abstracts. National conference on, “Conservation Agriculture: Conserving resources- enhancing productivity” September 22-23, 2004, New Delhi. Pp 9-10.
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Nayar VK and MS Gill. 1994. Water management constraints in rice-wheat rotations in India. Pp 328-338 in 'Wheat in heat stressed environments: irrigated, dry areas and rice-wheat farming system' ed. by Saunders D.A., Hattel G.P., CIMMYT, Mexico DF. Sharma RK, RS Chhokar, ML Jat, Samar Singh, B Mishra and RK Gupta. 2008. Direct drilling of wheat into rice residues: experiences in Haryana and Western Uttar Pradesh. In “Permanent Bed and rice-residue management for rice-wheat systems in the Indo-Gangetic Plain” (eds: E Humphreys and CH Roth). ACIAR Proceedings No. 127. Pp 147-158. Unger PW. 1991. Organic matter, nutrient and pH distribution in no- and conventional- tillage semiarid soils. Agronomy Journal 83,186-189. Yadav RL. 1998. Factor productivity trends in a rice-wheat cropping system under long-term use of chemical fertilisers. Experimental Agriculture 34,1-18.
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Production Technology of Ginger under Changing Climate H Dev Sharma and Vipin Sharma Department of Vegetable Science Dr YS Parmar University of Horticulture & Forestry, Nauni, Solan-173 230 HP
Ginger (Zingiber officinale Roscoe), a herbaceous perennial plant 30-100 cm tall having the underground rhizome that is cultivated as an annual, belongs to the family Zingiberaceae is an important cash crop and one of the principal spice crop all over the country and world. It is a crop with very rare flowering (0.5-67%) having yellow colour with dark purplish spots and in some cases do not flower at all and natural seed set has not been reported so far. It is native of South East Asia and originated in Indo-China region. India is the largest producer with more than 50% of the world production and exporter of ginger besides domestic consumption. China, Jamaica, Nigeria, Taiwan, Syria and Leone are other major suppliers of ginger in the global market. The USA, UK, Saudi Arabia, Canada, Japan and Singapore are the major importing countries. In India it is grown in an area of 149,100 ha with a production of 702,000 MT mainly in the states like Kerala, NE States, Sikkim, HP, WB, Odisha, TN, Karnataka, AP and Maharashtra. The crop occupies maximum area and production in Kerala while maximum productivity in Meghalaya. Kerala contributes maximum dry ginger i.e. sounth which is marketed internationally under the trade name “Cochin ginger”. However, India enjoys from the times immemorial a unique position in the production and export of ginger but the countries like Jamaica, Syria, Leone and China have throne a greater challenge to the Indian dried ginger in the international market. In HP, the ginger is grown in an area of 3,495 ha with a th production of 50,034 MT. It is a cash crop of mid and low hills and more than 3/4 of the area and production is mainly from District Sirmaur. The other ginger growing areas are Solan, Bilaspur and Shimla and about 90% of ginger produced in the state is exported as fresh to the adjoining states like Punjab, Haryana, Delhi, UP and Chandigarh and generate a good income to the farmers of the state. Ginger of commerce is the dried rhizome. It is marketed in different forms such as raw ginger, bleached dry ginger, ginger powder, ginger oil, ginger oleoresin, ginger ale, ginger candy, ginger beer, brined ginger, ginger wine, ginger squash, ginger flakes etc. It is useful in gastric, cold and cough. India is gifted with heterogeneous landforms and variety of climatic conditions such as the lofty mountains, the raverine deltas, high altitude forests, peninsular plateaus, variety of geological formations endowed with temperature varying from arctic cold to equatorial hot and rainfall from extreme aridity with a few
cm (
