HortgroScience - Tech Book - Version 6.indd

THE TECHNOLOGY COLLECTIVE HORTGRO SCIENCE TECH BOOK

2015

MANAGER’S PERSPECTIVE - PAGE 01

RETURN ON INVESTMENT - PAGE 03 - Art of Mutualism - Bigger and better through research: Plum cultivar development - EPN - our Biological Superweapon? - Crystal balling storage life: The DPA dilemma

CROP PRODUCTION - PAGE 21

CONTENT

-

Introduction Wiehann Steyn On tour Down Under Poland apple industry in crisis Shade netting - a burning issue Rootstocks for early nectarines in a low chill region Research on Track: Mechanical Blossom Thinning Op Dreef: Navorsing oor Gebreekte Pit in Pruime Stone fruit: mechanical vs hand thinning Orchards of the Future Fonteintjie roep… Does foliar application of BA increase fruit size in pears? What are the physical characteristics of a good nursery tree? Steenvrugtelesse: boordvestiging

CROP PROTECTION - PAGE 68 -

Introduction Matthew Addison Developing an Apple Scab Management Programme for South Africa Shredding leaves in autumn lowers apple scab levels in the next season Verwydering van blare op boordvloer help keer appelskurf

G EN ERA L M A NAG ERS REP O RT

HORTGRO

HORTGRO SCIENCE - RESEARCH FLOW

Science’s primary purpose is to generate and transfer knowledge, Hugh Campbell

technology and practices required

it is a requirement that all the research that is funded by the industry is published in the SAFJ. However, as there isn’t a searchable site to access all the articles published in the SAFJ, growers would need to search through old SAFJ’s in order to access the relevant articles. The Tech book will be released in conjunction with the HORTGRO Science annual report. This will allow growers to review what research is currently being done by reading the annual report and then access the published outputs of research by reading the Tech book. This will also be accessible on-line.

to mitigate, avoid or overcome threats/risks. Furthermore to exploit opportunities which have an impact on the ongoing economic sustainability of the South African pome and stone fruit producers, while ensuring the development and retention of skills.

01

CROP PRODUCTION ‘Orchard of the Future’, farming efficiency, rootstocks, plant quality, water and climate research.

The key outputs of research are technology and knowledge development and the development of people. Readers are encouraged to read the series of articles listed under ‘return on investment’.

We use many different platforms to land the technologies and knowledge developed by the pool of researchers who conduct research on our behalf. These include the HORTGRO Science Technical Symposium, seminars, field days, workshops, workgroups, technical forums, orchard walks, study groups, short courses, scientific publications, popular articles in the SA Fruit Journal (SAFJ) (and other popular publications), Fresh Notes, Timely Hints, annual reports, guidelines, pamphlets, bulletins, protocols, the HORTGRO Science website, Facebook, Twitter and we are currently finalising an App for stone fruit!

It is a reality that most of the research that we do is incremental and takes place over a period of time. These articles along with previous articles were written to reflect on some of the cumulative outputs of research. The articles showcase the benefits of the plum breeding and the Entomopathogenic Nematode (EPN) research programmes, while the article on ‘the DPA dilemma’ sheds light on the process of finding alternatives to DPA for the control of superficial scald. ‘The Art of Mutualism’ article should be read and studied in great detail as it relates to the unacknowledged role that research plays in developing the technologist of the future. We need to recognise the different links in the supply chain of producing a qualified technologist. This starts with the output of matriculants with maths and science as subjects and the attractiveness of agriculture as an industry in which to work, through to the retention of senior academic staff in universities. Read the article to get more insights!

There is however, a disjuncture between when the information is presented to the end user of the information and his or her need for the information. So, you might read or see an article about mechanical thinning but only have a need for the information at a later date. The objective of this Tech book is to package what has been published in the SAFJ over the previous year (2015). This is particularly relevant as

We trust that this Tech book will add benefit to your business. We are learning that feedback is the lifeblood of good communications – so please let us know if this Tech book meets a need and which improvements can be made.

01

CROP PROTECTION

03

02

Plant pathology, nematology (e.g. entomopathogenic nematodes), entomology (e.g. fruit fly).

04 POST HARVEST

RETURN ON INVESTMENT

Protocols and fruit quality maintenance, storage techniques, market access, decay control, fruit quality prediction, chemical residue reduction, packaging, transportation systems.

Quantifying the economic benefit the grower derives from applied research.

02

THE ART OF MU TUALISM

In biology mutualism refers to the way two organisms of different species exist in a relationship in which each individual benefits. In the deciduous fruit industry a similar relationship exists between academia and the growers on the ground. Elise-Marie Steenkamp investigates this beneficial relationship and looks at future challenges. From the outside the Lombardi Building in Victoria Street, Stellenbosch, looks pretty much the same as all the other university buildings: grey and stately. However, it houses the last surviving stand-alone horticultural science department in South Africa. At all the other institutions, the horticultural departments had been downsized, or integrated into general biology departments. This trend is not unique to our country.

science this year. “Most of them will find work in the various fruit industries, but too few will end up in research.” Dall believes that we are not generating enough human capital for the industry. As a consultant who works with farm managers he is constantly on the look-out for BScAgric students to fill farm manager positions. However, over the last two years he has not managed to find one. The same is true of consultants there is too much work and not enough consultants.

Emiritus Prof Ian Warrington, board member of the ISHS, said in an interview last year, that agriculture and horticulture the world over face immense pressure as a result of reduced political influence and little interest on the part of young people to follow careers in land-based industries.

An illustration in point is Citrus Research International (CRI), which has been looking for a researcher for a number of years and even tried finding someone abroad, but without luck. “I think that growers do not give enough recognition for the work that scientists and researchers are doing, especially the applied scientists. The reality is that we as consultants would not be able to do our work, if it weren’t for good applied research,” says Dall.

“The skills levels required by those working at every stage in the horticultural industry are all at higher levels than ever before. When I was considering doing a PhD some 50 years ago, there were 20 universities in the US I could have gone to. Now there are only two or three that would meet those needs.”

▶ The importance of researchers Evidence from many countries over the past five decades show that investment in agricultural research and development (R&D), education and rural infrastructure yields much higher returns than other expenditures, such as input subsidies. “Many studies have proven that research has the highest ROI of any investment,” says Dr Mias Pretorius, technical advisor at Two-a-Day. “The problem is that research is intangible and cannot be measured physically. If it weren’t for research we wouldn’t have had an industry. And we have to acknowledge the role that applied scientists play and the value that they add - otherwise we are heading for troubled waters. People are fundamentally important to the industry. Without people we don’t have an industry. And we are in crisis. For many years in agriculture many things were for free, but now

03

Dr. Mias Pretorius

Dr. Louise van Schoor Tienie du Preez

it’s a different story and growers have to pay for information, in essence pay for research.”

Prof. Wiehann Steyn Willie Kotze

how my own business grew – suddenly the demand was great and I could appoint other technical staff and improve the information flow. I also realized that the company needed specialists on more than one discipline to supply one stop shop technical advice.” Tienie believes that you start every day with your Bible and people. “People are always number two on my list, that’s why it is critical that you choose the right people for the job.” Tienie deliberately took young people straight from university and taught them the ropes. “I was a soil specialist and recognised gaps in my own knowledge base and had to go back to university to fill that. It took me about seven years but by that time I was confident that i had a thorough understanding of the finer aspects of horticulture.”

“We regularly experience the effect of not having the right people available. There is a huge technical skills gap and few youngsters coming in to fill the void. That is worrying.”

Dr Louise van Schoor is an agricultural scientist who recently stopped doing research. Louise feels that even though she has always had positive relations with growers and have found them “eager and willing” to implement new research, growers often do not understand the often dilatory research process. “It takes up to one year just to establish a trial. Then another four years before you actually start getting results. Sometimes the industry needs quick solutions but unfortunately that’s not possible in science. There are many constraints in our field, due to seasonal and crop specifics,” says Louise. “I think it would be a good idea to get researchers and growers together so that we can explain the processes to one another.”

According to Tienie the students produced by the US’s Horticultural Science and Soil Science departments have a solid knowledge base that is invaluable. “I don’t think all the growers always appreciate and understand how valuable the technical guys are. I put a lot of energy and effort into training these guys and believe we should do everything possible to keep them in the industry. They are an investment – the industry capital – the future leaders of the industry. “Today most of our larger clients have university training themselves and they understand the value that we add to the industry, but I believe about 60% of growers do not share that perception – these guys rely on information they get from other sources. To change that perception problem is very difficult – in Afrikaans there is a saying: if you want to pick a gecko up by its tail, the tail will break off. It’s the same with some growers – I guess it’s a human thing. Up to now we walked with the head and the tail must drag along. If, however, you want to be number one you need to have access to expert technical information and where the consultant also takes responsibility for the advice given.

Tienie du Preez is a technical consultant and industry leader who deliberately starting building human capital twenty years ago. He explains why: “When I started my own business in 1992 it soon became apparent to me that there was a big gap between what academic researchers were doing and the use of that knowledge on the ground. I made it my mission to get the knowledge out there on the farms.” “Incredibly little was known. Initially people didn’t want to pay for practically applied information, but I recognised the need, and soon especially bigger clients started realising the added value to their business and they started asking for more. That’s

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Hortgro Science Tech Book 2015

South Africa faces the same dilemma, says Peter Dall, technical consultant and industry thought leader. According to Dall the main reason is agriculture’s bad image and that few regard it as a successful industry to work in. “We have a serious shortage of human resources in various fields in the industry, especially a shortage of researchers.” “We are not attracting black students, partly because our basic primary education system in South Africa is not up to standard. The learners don’t realise how important maths and science are. When you do get students that are skilled in those two subjects they prefer to become engineers or doctors, not agriculturists.” According to Dall there are 10 final year students at the department of horticultural

Peter Dall

▶▶ Challenges

MSc (1993-2012) careers N = 114

PhD (1993-2012) careers N = 23

50

50 45%

40

30 20

05

20

17% 9%

10

4%

13%

9% 4%

0

Unkown

2%

Foreign

Outside

4%

10%

Emigrated

7%

Student

Academic

Breeding

2%

4%

Production

Technical

%

6%

Management

0

7%

Research

10

11%

22%

%

06


“It is through the foresight of my predecessors that Stellenbosch University is in this unique position as they have always strived to maintain a strong department with close interaction with the industries it serves. It is important to maintain this interaction as the four year academic programme trains students for a professional career and the training therefore needs to be very relevant to industry. The biggest danger for an academic department is to lose senior academic staff as it takes time for younger academics to find their feet in both academia and industry. Careful succession planning is therefore important. Also the pressure from the University is towards academic output and academics are not rewarded for working closely with industry on industry related problems.” Prof Karen Theron - Chair in Applied Pre-Harvest Deciduous Fruit Research at Stellenbosch University.

26%

30

Foreign

40

Emigrated

ROI • Human Capital • Technology • Knowledge

Outside

Research Projects ‘15/16 • Total Projects 109 (61 Pome / 38 Stone) • New Projects 21 (Pome 13 / Stone 8)

Research

GDP Annually • Stone R2.28 billion • Pome R8.2 billion

The only solution believes Prof Wiehann Steyn, Crop Production Programme Manager at HORTGRO Science, is to build human capital. “We have to grow our own wood.” In An effort to secure the future of the South African deciduous fruit industry, HORTGRO Science through the funding of Saappa and Saspa has invested more than R15 million over the last ten years in “human capital” – creating on average 30 – 40 postgraduate bursaries annually with this scheme. “If we do not develop capacity through research we will not have industry leaders tomorrow. The industry needs a constant streaming of highly skilled young people to help us keep the competitive edge.” According to Prof Steyn research has three outcomes, of which technological development is the easiest and most tangible to measure. “The development of knowledge is more difficult to measure but inevitably leads to technological development. Lastly, research leads to the development of people – the human capital without which the industry won’t be able to survive.

Academic

Experential Learning • Universities’s • Research Institutes • Sustainable growth • Development • Knowledge

▶▶ Building human capital

Technical

HORTGRO Science • Facilitates • Consults • Round Table

According to Tienie, it has always been his concern that there aren’t enough youngsters to replace the old wood. “When we started farmsecure the concept was to establish five or so crop divisions with each division consisting of a horticulturist, an irrigation specialist, crop protection specialist, nutritionist and orchard planner and a teamleader. We were talking of a group of about 35 people. We couldn’t gather those specialists – there aren’t enough of them.”

Management

Farm Gate • Profit • Investment • Sustainable farming • Feeding the world

Levy • 706 Pome Fruit Producers • 0.3% of GDP • 925 stone fruit producers • 0.7% of GDP

Willie Kotze, 28, until recently HORTGRO Science’s Regional Fruit Researcher, has now joined Dutoit Agri in Ceres as technical advisor.

“I think we are getting some things right,” says Prof Steyn, “in that we have over the years developed incredible human capital for the industry through the postgraduate studies that we have been funding. It is important to maintain a strong focus on human capital development and to take very good care of the researchers and technical experts in the industry. We will have to think innovatively to attract more local postgraduate students and to ensure that we maintain applied research capacity at University, ARC and private research companies.”

“HORTGRO Science was a huge stepping stone for me,” says Kotze. “It not only helped me to develop as a person, but also gave me the opportunity to develop my technical knowledge, my research skills and gave me huge exposure to the industry. The fact that I was based in Grabouw with the Two-a-Day guys was extremely beneficial. I was exposed to a broad segment of people in the industry on a day to day basis - what they do and what the challenges and problems are. Every time I jumped into the bakkie or grabbed a coffee with someone, I learned something new.” Willie feels that the move to big business came at the right time. “Previously I had one foot in research and one foot on the ground, now I will be given an opportunity to really apply all that I have learnt.”

▶▶ What return do we get for investing in people? When we look at the Department of Horticulture at Stellenbosch University over the last twenty years (1992 till 2012) – 13 of the PhD and 61 of the 115 MSc students that were educated in horticultural science studied on some or other deciduous fruit issue. (See page 6) What is interesting about our industry is that the retention rate is high, says Prof Steyn. “Of the MSc’s, 69% stayed in the deciduous fruit industry and another 15% came over to us from other study fields; 77% PhD’s stayed with another 20% joining our industry from other horticultural fields.” At HORTGRO Science the deliberate development of young people in the industry, for the industry has paid off.

PhDs

YEAR

CURRENT OCCUPATION

Karen Theron Nigel Cook Wiehann Steyn Elmi Lötze Mias Pretorius Louise van Schoor Elke Crouch Esmé Louw Mariana Jooste

1993 1999 2003 2005 2006 2009 2011 2011 2012

SU Chair in preharvest horticulture Private consultant HORTGRO Science HORTGRO Science/SU Horticulture (nutrition) Two-a-Day Technical Dept. HOD Private company (audits) SU Horticulture (postharvest) SU Horticulture (dormancy) HORTGRO Science/SU Horticulture (postharvest)

MSc’s Tercia Marcos Gert Marais Karin van Rensburg Petru du Plessis Johan Coetzee Hein Coetzee Hannes Halgryn Evelyn Jacobs Pierre du Plooy Janco Jacobs Schalk Reynolds Stephan du Plessis Kobus Meintjies Werner-Marcell Pieterse Louis Reynolds Stephan Marais Hannes Laubscher Karie Doorduin Jorika Joubert Graeme Krige Waldo Maree Tinashe Chabikwa Nelius Kapp Stephanie Roberts Fhatuwani Thovoghi Anton Gouws Brian Makeredza Robert Wilsdorf David Hendricks Willie Kotze Prins van der Merwe

1995 1995 1995 1995 1998 1998 2000 2000 2001 2001 2001 2003 2004 2004 2004 2005 2006 2006 2007 2007 2007 2008 2008 2009 2009 2010 2011 2011 2012 2012 2012

Marketing Delecta, technical Capespan, technical Grower and private consultant Agchem manager Trucape, marketing Monteith trust, technical manager Grower Private consultant Grower Philagro, technical manager Delecta, export and technical Agchem, technical ARC breeding and evaluation Private consultant Nulandis, R&D Dutoit Agri, Technical Dept HOD Stargrow, technical Farmsecure, technical advisor Two-a-Day Technical Dept. Stargrow, technical PhD student in biotech Private consultant Omnia, research Lecturer at Univ. of Venda KROMCO, quality assurance PhD student in horticulture at SU Viking, technical Nulandis, R&D Dutoit Agri, Technical Dept Experico, research

08


07

▶▶ Some of the PhD and MSc graduates (1993-2012) who studied on projects funded by SAAPPA and SASPA and who are working in the deciduous fruit industry.

BIGGER AND BET TER THROUGH RESEARCH In 1974 South Africa produced only 0.2 percent of the world plums because of a lack of suitable cultivars for the environment. It was therefore necessary to breed improved cultivars that would breathe new life into the country’s plum industry.

Elise-Marie Steenkamp

Outstanding quality, good yielding performance, durable disease resistance with a low input of chemicals, high international demand resulting into money rolling into the bank account – this is the kind of cultivar growers dream about.

A Zimbabwean city girl who knew nothing about agriculture apart from watering her father’s vegetable garden took up the challenge of investigating whether breeding evaluation and research really pay in the South African deciduous fruit industry.

ARC’s forerunner).

As part of her Master’s thesis in agricultural economics, Precious Tshabalala (27), placed the local plum breeding and research programme under the spotlight. “It started out as just another project that I had to finish in order to get my degree,” admits Precious, “but I soon fell in love with the deciduous fruit industry and now want to make it my career.”

“In South Africa the deciduous fruit industry has also yielded significant benefits, as continued investments have led to the development of over 300 deciduous fruit cultivars, and more continue to be developed to meet the evolving needs of both producers and consumers,” said Precious.

“I decided to focus on plums as the cultivation of this fruit was exceptionally difficult within the South African environment – and one that would have been impossible without breeding and research.” According to Precious ample international research showed that by investing in agricultural research and breeding development, you greatly enhance global agricultural production.

During the course of the last 15 years, 63 stone fruit cultivars were released into the agricultural sector of South Africa through the ARC’s stone fruit breeding programme alone, and 59 percent of these were released in the last five years. With most of the plums available in stores being varieties belonging mainly to the Japanese plum1 group Prunus salicina, a vast amount of research has gone into producing plum varieties that are adapted to South African climatic conditions. Since the inception of the plum research programme at InfruitecNietvoorbij over 23 varieties have been released and several crop management recommendations were made.

She focused on the Agricultural Research Council’s (ARC) stone fruit breeding programme at Infruitec/Nietvoorbij – as they were historically associated with plum research in South Africa, with the first trials dating back to the early 1940’s (done under the Western Province Fruit Research Stations (WPFRS) - the

But, where did it all start?

▶ Cultivar development and breeding - SA style South Africa was largely dependent on plum cultivars imported from Europe and America, until the WPFRS was formed. Initially research was based on similar projects pursued in Chile, but due to the poor performance of the cultivars that existed at the time, research had to be aligned with the needs of local growers.

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The ideal plum which was being sought was one which would be bold, firm and juicy. With a body not prone to being mushy, that would have the ability to withstand three weeks’ storage at – 0.5 . However, this required many years of research before the desired results would be obtained. Initially the plum-breeding programme focused on developing a large-fruited early plum variety. Disaster struck when the industry was hit by the catastrophic bacterial spot (Xanthomonas pruni) in 1960. This disease caused plum trees to lose their leaves, fruits ended up being discoloured, mottled and spotted - reducing yields by up to 50 percent. Consequently growers were hit hard with huge financial losses. The plum breeding programme made it a priority to find a bacterial spot resistant cultivar. Several years were spent on crossing, back-crossing, and evaluating promising selections. The first locally bred plum was released in 1972 under the name ‘Songold’. Songold was well received in the industry and adopted by many growers. Exports soon grew and growers realized that it was more profitable to replace the old cultivars with the new and improved cultivar. Today, Songold remains the second largest produced and exported variety.

Laetitia (released in 1985), became the rock star cultivar of the industry. It was specifically bred to ensure a uniform supply of plums to the markets. The first tree plantings were in 1980, yielding 5 kg per tree in 1982. The following year, the yield had doubled to 10 kg of fruit per tree, and by 1984 this had gone up to 25 kg per tree (Bester, 1985). The performance of Laetitia superseded that of all other varieties and it has maintained its position as leader in terms of area planted and volumes exported. Laetitia’s popularity also grew due to its high resistance to the bacterial spot disease. Today Songold and Laetitia are two of the most successful cultivars ever bred locally. Both cultivated on an area comprising 28% of the total area on which plums are planted.

In 1973 a new mid-season cultivar Harry Pickstone was released, to replace Wickson. The improved characteristics that it possessed were its ability to self-fruit and its resistance to bacterial spot. The cultivar had good cold storage ability and it could bear fruit well. It is harvested early January and today remains one of the top 30 exported cultivars in South Africa.

▶ New Cultivars of Note

Other cultivars released thereafter include: Celebration (1989), Sapphire (1992), Souvenir (1993), Pioneer (1995), Lady Red (1996).

Sun Kiss and Sundew (1999), were the first full bright yellow plums bred locally, and are both registered under the trademark African Pride®. They were developed to close the gap in the European markets post-Christmas. African Pride is a unique South African product, as it remains yellow even after ripening, has good storage ability and was the first to be released under controlled commercialization. Sun Kiss is among the top eight most exported cultivars in South Africa, whilst Sundew, although among the significant export cultivars, has been lagging behind. Ruby Red, a mid-season variety, soon followed. This cultivar has good storage ability, higher yield and is of better quality than other varieties. In 2003 two more yellow plums, Golden Kiss and Sun

In 1977 the third locally bred mid-season plum cultivar, Reubennel, was released. The cultivar was deemed to have superior characteristics to its breeding parents (Gaviota, Wickson and Methley). It was resistant to bacterial spot, had reduced delayed foliation, and had good yield and fruit size. Reubennel is still amongst the top 14 exported cultivars to date.

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But finding fruit cultivars that flourish naturally within the South African climate has always been a challenge for local growers. It is therefore not surprising that as early as 1945 researchers were called in to help develop technologies and breeding cultivars to enable growers to participate in the world market.

Precious Tshabalala

By 1982 improved cultivars represented more than 60 percent of the plantings. Plantings increased as new producers entered the field and there were dramatic increases in total production. Sixty-six percent of the total quantity produced was ascribed to new cultivars — all mid-season varieties — and the industry was faced with the hurdle of peak deliveries with gaps in-between. To curb this, plums would be stored for long periods with the consequence that the fruit arrived at overseas markets in poor condition. The problem would only be solved by developing a new cultivar that would fill in that gap between peak deliveries.

C R Y S TA L B A L L I N G S T O R A G E L I F E : T H E D PA D I L E M M A Breeze, were released, with Sun Breeze being an improvement on Songold. Amongst yellow plums, Golden Kiss was outstanding in terms of cold storage and shelf life performance. However, Sun Breeze failed to live up to its expectations and five years later it was not amongst the significantly produced cultivars. Golden Kiss is still in the top 24 significantly produced and exported cultivars in the country. In 2008, Infruitec released the much anticipated African Delight plum whose aim was to reduce production costs. This cultivar was well received by producers as it had the following characteristics; high sugar content, good storage ability allowing the marketing period to be manipulated, and low chilling requirements. Due to its excellent performance, within four years of its release, this cultivar was the country’s fourth largest produced and exported variety. Further new releases and improvements on existing plums, include: • Solar eclipse (a black-skinned plum), • African Rose (a red-skin early season plum), • Ruby Star (an early season red-skin plum). These cultivars have great potential as they have all proven themselves to have a high yield/tree ratio of more than 20 kg/tree. Other improvements include: • Ruby Sun – a late-season red-skin plum which is an improvement on Sapphire • Red Crunch a red-skin plum, as well as Satin Gold a yellow plum which is an improvement on Songold. Although impressive results have come out of the plumbreeding researchers at the ARC continue to breed in pursuit of more new and improved cultivars.

said that understanding the importance of the lag structure of R&D is crucial. The lag structure refers to the effects of investing in research over time. “The lag structure emphasizes the need for regular and stable funding, otherwise you lose out on the profit that research brings – even ten years down the line.” According to Liebenberg in countries like Nigeria – where research funding is unstable - one can clearly see the impact it has on capacity. Lag structure showed that research can even have an impact on an industry up to 55 years after initiation. When you think about it that way, it is really scary, and if R&D is cut the negative effects will be felt by the next generation long after we are gone.”

In 2008, discerning industry role players anticipated the restriction of fruit storage elixir Diphenylamine (DPA) by the European Union (EU). In response to this threat they launched an innovative research strategy, exploring alternatives to DPA, and to allow growers to still export to the EU. Elise-Marie Steenkamp investigates the DPA dilemma and the timely germination of various research projects that resulted in several tools in the box for growers. Apples and pears are harvested once a year and kept in cold storage for as long as twelve months. South African fruit growers wanting to deliver quality deciduous fruit from the remoteness of southern Africa to other parts of the world, have always had to find innovative ways to extend storage life.

Richard Hurndall

A failure to increase publicly funded agricultural R&D will likely have long-term consequences for the sustainability of agriculture in a competitive global environment and for the natural resources on which it depends.

▶ ROI The aim of the study was to estimate the rate of the return on investment (ROI) of the plum research breeding and evaluation and research programme at Infruitec/Nietvoorbij. The period evaluated were from 1980 – 2012. The study found that the ROI of the plum research programme was 14.23 % with a ten year lag.

The results of the study imply that plum research was beneficial for the industry and that investing in profitable technologies can improve agricultural productivity. It just makes economic sense for beneficiaries to fund R&D efforts, thus reducing the reliance on public funds, said Liebenberg.

“Cold storage is essential as it lengthens our marketing period to deliver good quality fruit,” says Richard Hurndall, HORTGRO Science Research and Technology Manager. “The tabooing of DPA for superficial scald control by the EU potentially meant a reduction of imports of apples and pears from South Africa to the EU.” Kobus van der Merwe

DPA - originally a vulcanizing agent to stabilise rubber - has been in use to prevent superficial scald in apples and pears in South Africa since 1962. The World Health Organisation (WHO) evaluated the safety of DPA several times since the 1960’s. In 2007 the WHO stated that, “the long-term exposure was unlikely to present a public health concern”. “It has always been a tricky thing,” says Hurndall. “Public opinion usually holds sway in the EU, and there is no silver bullet for replacing something like DPA.” “We realised that we needed a coherent strategy for life without DPA,” says Hurndall. “We got together a working group to strategize and investigate alternatives to DPA. When the axe finally dropped, we already had a couple of tools in our box and we could advise the growers about the way forward.” Early in 2008 the European Food Safety Authority (EFSA) began pressing

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“We used an analysis technique to estimate the lag structure that exists from the time when research and development investments were made, to the time when the effects are felt. In this regard we found that the effects of the R&D were immediate and highest return was experienced in the fifth year. In a 10 year lag, significant relationships between R&D investments and output were experienced in all the years. These relationships were all statistically significant (at a confidence level of 95%),” said Tshabalala. Dr. Frikkie Liebenberg, Agricultural Economist from the University of Pretoria and supervisor for the thesis,

Superficial scald, a physiological disorder of some apple and pear cultivars, creates problems for cold storage and long shipping periods (up to 6 weeks for long-haul destinations). However, such discolouration is prevented when fruit is drenched in DPA - an antioxidant which controlled several postharvest disorders - that subsequently became the cold storage treatment of choice.

the chemical industry for more information about DPA. The World Apple and Pear Association (WAPA) requested inputs from member countries, including South Africa, regarding cultivars and volumes affected by the possible non-inclusion. Following a survey of local packing operations, South Africa provided statistics, together with a strongly-worded objection to the WAPA. European officials, however, were not satisfied about the safety of DPA.

“HORTGRO Science foresaw the problem - we anticipated the nonavailability of DPA for the EU market; evaluated various options, and looked for various strategies and research to deal with the non-use of DPA; and developed a toolbox with solutions for growers.” Richard Hurndall

WHAT IS SUPERFICIAL SCALD?

▶▶ DPA Fact File

Superficial scald is the brown

• •

discolouration that occurs on the skin of the susceptible apple and pear cultivars after a period of

•

approximately 2 months in cold storage and as a result of the

• •

breakdown of natural antioxidants. It is usually initiated in cold stores and

•

develops after transfer to ambient

•

temperature. In severe cases superficial scald can develop in cold storage.

1962

1990’S

DPA approved for use in SA to prevent superficial scald.

EARLY?

Bertie Truter at ARC starts trials looking for alternatives for DPA.

1960’S

WHO

2000

Regular DPA evaluation by WHO (health and safety).

2007

WHO

WHO declares: “Long-term exposure to DPA unlikely to present health concerns.”

Experico* commissioned by Agrofresh Inc. to do registration trials for SmartfreshSM (1-MCP or 1-methylcylopropene) on apples and pears.

13

*Capespan Technology Development, as the unit was then known

In anticipation of DPA restrictions, HORTGRO Science initiated research projects to investigate alternatives to DPA, such as Dynamic Controlled Atmosphere (DCA), single and repeated initial low oxygen stress (ILOS) and others. “Our main objective was to provide growers with viable alternatives to DPA,” says Richard.

“We did have the option to continue using DPA and lose the EU/UK market, but then we had to find alternative markets fast. 42 percent of our apples and 78% of our pears were destined for the UK/EU, which is a big market to lose.”

Luckily SmartFreshSM, albeit more expensive, which also controls superficial scald, was introduced some time ago. In 2000, ExperiCo, or Capespan Technology Development, as the unit was then known, was commissioned by AgroFresh Inc. to do registration trials for SmartFreshSM (1- MCP or 1-methylcylopropene) on apples and pears. SmartFreshSM is however not suitable for certain pear varieties such as Packham’s Triumph. This is where research conducted at the Agricultural Research

2008

HORTGRO Science, discerning industry role players anticipate restriction: launch strategy exploring several alternatives to DPA.

2008

European Food Safety Association (EFSA) pressurise chemical companies for safety ‘proof’.

DPA on its own is not believed to be harmful, says Kobus van der Merwe, ARC researcher and DPA expert. However, of the concern was related to impurities; carcinogens called nitrosamines – not something you want to find on your everyday apple.

2010

Several other trials commissioned. No great successes.

2010

2012

DCA trials start.

EFSA: “Chemical industry failed to prove DPA safety”.

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2013

MRL reduction: EU slashed tolerance level 0.1part/million.

2015

Grower toolbox: DCA; ILOS; SmartfreshSM


DPA ‘silver bullet’ against superficial scald.

In South Africa DPA amounts to drench treatment; whereas in Europe they use thermo-fogging – which amounts to a vapour applied in a room, thereby increasing the risk of contamination of the room. In the gas stage, DPA infuses everything within the room. DPA breaks down over time. The DPA used in the fruit industry is “a benign growth regulator”, also called an “antioxidant”. Scald is a major defect with tolerance between 1 – 2%. EU MRL reduction: - The maximum residue level (MRL) for the use of DPA in EU/UK up to the end of 2013, was 10ppm for pears and 5 ppm for apples.

•

Council (ARC) into DCA demonstrated that the technology controlled scald on Packham’s Triumph (and other pear cultivars) under South African conditions. DCA also controls scald on apples but there is a limitation of at least six weeks of subsequent regular atmosphere before scald may reappear. Dissatisfied with the “poor investigation,” the European Food Safety Authority (EFSA) concluded that the manufacturers had failed to prove that DPA was safe and, in 2012, severely limited its use on apples. In March 2013, the EU slashed the tolerance level of DPA on imported apples to 0.1 parts per million - so low a level that nobody would be able to adhere to it.

- In the rest of the world it remained unchanged. - From 2014, new MRL regulations imposed a 0.1 ppm limit (100 x less than the norm). Fruit that were previously treated with DPA in South Africa, include: - Apples: Granny Smith, Red Delicious, Cripps’ Pink, Cripps’ Red, Golden Delicious, Braeburn, Fuji and Pears: Packham’s Triumph.

SO WHAT WOULD HAPPEN IF MRL IS EXCEEDED? It would be declared illegal to sell fruit with an MRL over the determined level, resulting in the return of the fruit at the grower’s cost and/or the rerouting of the fruit to another market outside the EU/UK. The biggest problem now with DPA is the contamination that occurs during its gaseous phase. In South Africa fruit is drenched in DPA; whereas in Europe fruit was thermofogged – which amounts to a vapour applied in a room, thereby increasing the risk of contamination of the room.

“South Africa’s fruit industry is unique and we have unique challenges,” says van der Merwe. Twenty years ago, researchers like Bertie Truter, were already looking for alternatives to DPA. Bertie Truter conducted research on ILOS, which was partially successful for limited storage periods.

According to van der Merwe, research showed severe and far-reaching contamination of cold stores, wall joints, porous surfaces, bins (plastic and wood), and even the paint on the walls. Also pack lines, all fruit contact surfaces, and flumes may be contaminated.

“We have limited resources and infrastructure, but we still manage to provide the industry with excellent research. I honestly think our researchers deserve a medal for what they have achieved. As they say, ‘‘n Boer maak ‘n plan’.”

“Growers were faced with huge dilemma and had to make serious decisions about their marketing plans,” says Richard Hurndall. “If a grower planned on supplying the EU/UK market they had to dedicate infrastructure to being DPA-free – as anything that was remotely touched by DPA was potentially contaminated without a prospect of being cleaned. Research by Experico has subsequently shown that the risk of contamination from bins, walls and other surfaces is relatively low. The risk is highest when fruit treated with DPA is stored together with untreated fruit.

In the end there were 2 feasible alternatives to DPA i.e. DCA and SmartFreshSM, with others such as single and repeated ILOS currently being evaluated. In addition research was conducted to identify the risks of contamination with DPA and results showed that it is only a high risk if treated fruit is stored in the same room as non DPA-fruit. The combination of SmartFreshSM treatment with DCA is gaining prevalence in Europe for better quality and shelf-life.

▶▶ Alternatives to DPA Non DPA superficial scald control strategies

Treatment 1-MCP (SmartFreshSM) • All fruit should be of similar maturity. • Treat within 7 days of harvest. Multiple applications recommended to stay within 7 day protocol. • Do not mix cultivars • Cultivars for treatment: any apple cultivar susceptible to scald, except possibly Braeburn! Initial low oxygen storage (ILOS) • 6 - 8 months control for apples at 0,5% O2 and 1% CO2 for 10 days; then normal CA • 12 weeks control at 0,5% O2 and 1% CO2 for 10 days; then normal CA + 6 weeks RA on Packham’s Triumph from Grabouw (1 year’s data) • Repeated ILOS currently being trialled on Granny Smith

Effectiveness

Status / Constraints

• Effective control; • No detectable residues • Increased cold storage and shelf-life

• Product cost • Capacity limitations - require gas tight CA chambers

• Residue free

• Capacity constraints • Risk of treatment not being 100% effective

• Residue free • Effective control for 9 months

• Capital outlay • Management intensive • Post-DCA RA storage limitation

Dynamic CA

Other strategies, such as heat treatment, higher temperature storage, Vitamin C & E derivatives, were investigated, but are not effective treatment options at this stage.


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EPN - OUR BIOLOGICAL SUP ERWEAPON?

Elise-Marie Steenkamp

When Matthew Addison originally started thinking about using entomopathogenic nematodes (EPN) to treat codling moth infested wooden fruit bins, he never dreamed that it could possibly turn out to be a biological superweapon that could potentially save the deciduous industry millions of rands and in the process spawn a vast scientific research network.

Ten years ago, Addison, Crop Protection Manager at HORTGRO Science, had R30 000 funding but nobody to take the research further. A great believer in biological control as a fundamental aspect of integrated pest management he realised the potential, but was at a loss as to how to proceed. Dr Antoinette Malan, then Principal Plant and Quality Officer at the National Department of Agriculture, stepped in. Malan had at that stage, in an attempt to continue nematology at the Stellenbosch University, replace retired nematologist, Prof Bertus Meyer. “Even though I am a nematologist, I didn’t know anything about EPN’s. Nobody knew anything about them as it was a totally different concept. I had no one to ask, no one to train me. It was new to us all,” says Malan.

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Back in Stellenbosch Malan found an enthusiastic student, Jeanne de Waal, who was willing to take on EPN and eventually completed her MSc and PhD under Malan’s guidance. “Together we did research and taught ourselves.” It helped that EPNs are what Malan calls “model organisms”. “I previously worked with plantparasitic nematodes – notoriously difficult to study. EPN are exciting and highly satisfactory to work with. We were very motivated.” In 2003, the industry funded a survey of local EPN. The survey was important as nothing of the local EPN occurrence and distribution was known. The survey was successful and during the following year a project was launched that investigated the use of EPN for controlling codling moth larvae in fruit bins. During this time Citrus Research International also came on board and research was expanded to include false codling moth, mealy bug, and the banded

Dr Antoinette Malan Matthew Addison

commercialization of local EPN species.

fruit weevil. These positive results made it possible to develop culture methods for local EPN species and launch investigations into their physiology and temperature tolerances.

This grant will allow for commercial outdoor application of EPN in the different industries such as deciduous, citrus and grapevine. The research programme is still active and proposed research includes the integration of EPN with fungi that attack insects. If history is anything to go by, it will be an interesting and productive process.

Today the development of effective biological control agents for use in the deciduous fruit industry is regarded as a priority, says Addison. “Pest management cannot rely on a single method of control. It is imperative that we expand the management options available.”

For Addison a good analogy is that of a table that cannot stand on one leg. “The more legs - the more stable the object. The same with pest management.” The integration of biological control agents supplements existing management methods. They are stable over time and can be highly effective. EPN are an attractive natural option with the added benefits that they have adapted to local conditions and are generalists. Their positive effect on the environment cannot be measured in monetary terms, says Addison. To date the deciduous fruit industry has invested R 2.74 million and the citrus industry 1.2 million in the EPN research effort. Altogether 10 post graduate students have completed their studies, and 38 peer reviewed publications have been published along with numerous popular articles. The programme has drawn the attention of the pest management community, and a huge government grant was recently awarded to a development company, which will allow for the full


Nematodes are among the most ubiquitous organisms on earth. They occur in virtually every possible environment, either as free-living nematodes or as parasites of vertebrates and invertebrates. There are many different kinds of nematodes, but the ones creating the buzz are the insect-parasitic or entomopathogenic nematode or just EPN for short. EPN attack and feed only on insects. Malan was fascinated. She got onto the internet and

started researching the matter. She read almost every paper she could find and connected with international researchers. She soon found herself on a plane heading for the University of Florida, USA, to train and learn with Dr Khuong Nguyen. “He taught me everything: how to identify them, how to find them in the soil, and all the other research techniques.” Another big help was Prof Ralf-Udo Ehlers, then based at the Christiaan Alberts University of Kiel, in Germany.

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What is Biological Pest Control?

Trends and Future Possibilities in Biological Control

Biological pest control is the reduction of pest populations by using natural enemies. It is important because crop pests become resistant to chemical pesticides. It thus forms an integral part of the integrated pest management (IPM) approach.

• The advantages and limitations of biological control are viewed in comparison with chemical pesticides. • Natural predators are usually very specific in their range of prey. Natural enemies actively seek out their prey and can increase the level of control over time. The arguments against chemical pesticides are that they not only kill the pest, but also other species, including natural predators. Furthermore chemical control is limited to area application, frequent application may be required which are costly. • The main limitation of biological control agents is that it is a slow process which requires the predators to establish themselves. • EPNs as a biological control measure have had excellent results in closed orchards. • Future research will focus on applying EPNs in local “open” orchard conditions. • 50% reduction in a given pest population can be expected. • Elimination of pest individuals with possible chemical resistance. • Seeding of orchard soil with nematodes. • Secondary control against insects in soil such as fruit fly and weevils.

How are bio-control agents found? The first step is a survey of the natural enemies of the target pest. Researchers observe the natural cycle to make sure that the biological control agent does no other damage. Then it can be reared and released in large numbers. What are EPNs? Entomopathogenic nematodes are a group of nematodes (round worms) that kill insects. The term entomopathogenic has a Greek origin entomon, refers to insect, and pathogenic, which denotes causing disease. Although many other parasitic round worms cause diseases in living organisms, entomopathogenic nematodes are specific in only infecting insects. EPN live parasitically inside the infected insect host, and are therefore described as endoparasitic. They infect many different types of insects of which some stages are in contact with the soil, like the larval forms of moths, butterflies, flies and beetles as well as adult forms of grasshoppers and crickets. EPN have been found all over the world in a range of ecologically diverse habitats. The most commonly studied EPN are those that can be used in the biological control of Steinernematidae and Heterorhabditidae. Implications for growers? • Currently scientists are investigating the application of EPN to the soil and directly onto trees. • EPN cannot be treated the same as chemical applications – they are little animals and sensitive to environmental conditions. • Knowledge of handling nematodes is imperative for their success – especially a full understanding of their life cycle. • There are major differences between aerial and soil applications. • When applying EPNs aerially onto trees certain considerations apply: Insects such as codling moth and mealy bugs are highly susceptible; there is only a short window period for application; temperature and humidity remain the main problems – as trees must stay wet before and after application.

Did you know? • The use of biological control for the management of pest insects pre-dates the modern pesticide era. The first historical record of biological control dates back to around AD 300 when predatory ants were used to control pests in citrus orchards. In the modern era an imported ladybird was widely used to control cottony-cushion scale on American citrus crops in California in the 1880s. • There are about 120 EPN species worldwide with a total of 24 EPN species on the African continent – of which 12 are new discoveries. In South Africa 6 new species have been described.

Further reading: Bale, J.S., Van Lenteren, J.C. & Bigler, F.(2008): Biological Control and Sustainable Food Production, Royal Society London Biol Sci.363(1492):761- 776 http://rstb.royalsocietypublishing.org/ content/363/1492/761.abstract

The Big Challenge - Grower Education

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In an effort to produce more and better fruit, growers worldwide prefer pesticides as a means of pest control. It’ s not an easy task to convince growers to adopt a systems approach to pest management and make greater use of biological control agents. Once a good natural enemy has been found, it is important to train the extension service and farmers in its use. There is a big attitudinal barrier that needs to be broken down before growers will opt for biological control agents. Future pest management will depend strongly on biological control because it is the most sustainable, environmentally safe, although not the cheapest system of pest management. Biological control is expected to account for a significant increased proportion of all crop protection methods by the year 2050 (Bale, Van Lenteren & Bigler, 2009).

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55 784 000 TREES

LADDER MOVEMENTS

INDIVIDUALLY PRUNED, TRAINED, THINNED, HARVESTED UP TO 5 TIMES

60 APPLES PICKED PER/MIN

150G

AVERAGE FRUIT SIZE

LABOURERS EMPLOYED IN THE SOUTH AFRICAN FRUIT SECTOR FRUIT SECTOR - 108 404

CROP PRODUCTION 54 350

70 DAYS HARVESTING PER PERSON

APPLES

HECTARES PLANTED IN SA

906,827,000kg

23 625 AREAS (HA) APPLE PRODUCTION

33 063 328 APPLE CARTONS

R2150

WATER COSTS 6,045 BILLION APPLES 12 700HA PEAR TREES

42% PEAR EXPORTS GO TO EUROPE

12 697HA PEAR TREES

INTRODUCTION CROP PRODUCTION

Dear Deciduous Fruit Grower,

Prof Wiehann Steyn

The Crop Production articles published during 2015 in the SA Fruit Journal provides a snapshot of recently completed research. All project leaders commit (when we accept their research proposals) to write a popular article on their research findings for publication in the journal. This is because we know that many of you learn about the research done for you through the latter publication. We request the articles to be popular (i.e. easy to read “gesels trant” with nice, supportive photos) because we want them to be accessible to you as grower. We realise that scientific articles (which the researchers also need to write for their employers) are often difficult to read since they tend to be wordy (sacrificing readability for the sake of completeness and backing all statements with references) and scientifically intimidating (science articles generally require a formal writing style and uses very specialised – researchers will say precise – terminology).

is that is doesn’t provide the context of the research – where does it fit in, why did we do it, what will be the benefit to you, the levy-paying grower? 22

I thus come to what I thought would be of most benefit to you in my introductory piece for this first issue of our SA Fruit Journal HORTGRO Science Tech book article series, which would be to state the focus areas of the Crop Production programme and to indicate where each of these articles fit in.

The research conducted in the Crop Production programme, is aimed at achieving (literally) the Orchard of the Future and addressing the risks to it. The Orchard of the Future is highly productive, very uniform and considerably more efficient than our current orchards. We don’t want to rely too heavily on a weak Rand to stay competitive. We achieve this orchard by focusing on optimising our planting systems (productive rootstocks, efficient tree shapes and good nursery trees). The major Crop Production risks are water availability, climate change (drought, heat, lack of winter chill) and extreme climatic events (e.g. hail). The articles in this series may seem like a bit of a mixed bag, but they

all fit in with our overall objectives and stem from research needs identified by various workgroups. First of all, there is feedback on the demo-block “Orchards of the Future” where leading grower groups are trialling dwarfing rootstocks (M9 and Geneva) at higher plantings densities than the norm. Piet Stassen also reports on his stone fruit rootstock research – some of the new rootstocks are definite improvements over our industry-standard Kakamas and Mariana in certain specific conditions. Nets provide a way to soften the climate and address some of the main risks to the Orchard of the Future by decreasing the heat-load on the fruit and tree as well as by saving water. One of our great inefficiencies is the amount of fruit we send to juice. Research on broken stones in plums and increasing fruit size in Abate Fetel is aimed at increasing packout and, in the case of the plums, provide pointers to breeders. Mechanical thinning of stone fruit has great potential to increase orchard efficiencies and also fruit size – due to the earliness of the thinning. Gerrit van der Merwe’s evaluation of platforms has pointed out how labourer unfriendly our (mostly pome fruit) orchards are and has provided further impetus for the move to higher density, spindle or fruiting wall type orchards. Lastly, we have also included some articles stemming from overseas visits. Comparing our industry with our counterparts and competitors illuminates our strengths and weaknesses and also provide some direction as to the changes we should make in order to keep our Orchards of the Future competitive and profitable.

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Publishing our research in the SA Fruit Journal is, however, not the ultimate, perfect communication tool. A major shortcoming

We increasingly try to address these shortcomings within the articles – you will note the improvement in 2016 SA Fruit Journal articles. However, our research covers a very broad field and we do not have the luxury considering our limited space in the Journal to specify for every project exactly where it fits in.

ON TOUR DOWN UNDER

Four South Africans and Prof Luca CorelliGrappadelli of Bologna University in Italy, toured through the main fruit producing regions near Brisbane and Melbourne, Australia. HORTGRO Science Crop Production Manager, Prof Wiehann Steyn, shared his thoughts with Elise-Marie Steenkamp. Prof Karen Theron, from Stellenbosch University, Anton Müller, KROMCO technical advisor and Dr Piet Stassen, Agricultural Research Council researcher were also part of the group.

“The main aim of our visit was to network, survey the Aussie apple industry and evaluate their progress to date; we were also on the lookout for possible synergies – and found many,” said Prof Steyn. The first day of their tour was spent at Stanthorpe (about 3 hours west of Brisbane) on invitation by Dr Heidi Parks, a horticultural scientist from the Queensland Department of Agriculture, Fisheries and Forestry. “We visited several orchards and had discussions with researchers from Applethorpe Research Station about their work. All the orchards in this area - which reminded me of the Highveld - are netted, due to regular hail storms. We saw high density orchards using M9 or M26 rootstocks despite relatively mediocre soil. Climate change and dormancy are some of their main research priorities.” The group then travelled to Melbourne, Victoria, as guests of Kevin “Colonel” Sanders – a leading figure in the Aussie apple industry.

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•

“Saunders and his brothers are shifting the boundaries of high density apple farming and he has his own nursery that produces large, branched trees on M9 rootstock. He believes nursery tree quality is vital and non-negotiable for orchard success. He started his own nursery, because commercial nurseries did not deliver the standard of tree that he needs.”

•

Apple farming in Australia is an expensive business. Establishment costs are around R800 000/ha and operational costs are expensive with R350/hour as the minimum labour wage. This is why they focus heavily on mechanisation and automatisation as research priorities. They have a lot of hail and netting is everywhere and is not as expensive as in South Africa, because they have access to a lot of wood and poles are cheap. Despite the high establishment and operational costs, growers can break even after 5 to 6 years. This is because local supermarkets by-and-large only sell Australian apples, said Prof Steyn.

•

• •

•

“We visited the Tatura Research Station of the Dept. of Environment and Primary Industries at Shepparton where we met with researchers including: Dr Ian Goodwin (irrigation needs of apples); Dr Mark O’Connell (spatial technology and precision management of orchards); and Dr Rebecca Darbyshire (climate change predictions). There is great potential for collaboration with these researchers.”

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A lot of two-dimensional fruit walls on dwarfing rootstocks, M9 in particular – which makes spraying more effective, are “labour-friendly” and ideal for mechanisation. These structures are relatively simple and makes for good light distribution. We complain about the low productivity of our labour force, yet our trees are much more complex than those we saw in Australia. We also learned a lot about the Future Orchards programme and how they used it to modernise their industry and improve their use of technology in fruit orchards. Their challenge was to lower production costs, whilst improving production and quality. It seems as if they have been quite successful. The Aussie breeding programmes are impressive. Not only were the Western Australia breeding programme responsible for Pink Lady, but they have just come up with a new “Black Apple” that still needs to be named. Another new, scabresistant variety, Kaylee, is the product of the Queensland breeding programme. They focus a lot on developing precision tools for agriculture, because labour is so expensive. They did a lot of research on netting – they don’t have a choice due to sunburn, hail and pests such as parrots and flying foxes. Their research is also focusing on the impacts of climate change and their situation is similar to ours. There are great opportunities for possible collaborations, especially on irrigation, dormancy and fruit quality. (Dr Esmé Louw, researcher from the US Department of Horticultural Sciences, has already made contact with Australian colleagues; exploring possible research collaborations on dormancy). “I also strongly believe that we should focus research into the development of enabling technologies that will allow us to adapt to future adverse climatic conditions (i.e., lack of winter chill, heat waves, increasing frequency of severe weather events, decreasing access to irrigation water). Otherwise our goose will be cooked.”


On tour … in front of the Department of Agriculture, Fisheries and Forestry at Stanthorpe, Queensland, Australia; in the back row: Dr Piet Stassen, from the ARC, Profs Luca Corelli-Grappadelli, University of Bologna, Wiehann Steyn, HORTGRO Science and Karen Theron, Dept. of Horticultural Science at SU, Anton Müller,technical advisor KROMCO and Simon Middleton, Queensland Department of Agriculture, Fisheries and Forestry. In the front: Dr Heidi Parks, Alan McWaters and Osi Tabing, all from the Queensland Department of Agriculture, Fisheries and Forestry.

▶▶ What we saw:

On the last day, the group visited the Yarra-valley, south-east of Melbourne, where Colonel Saunders showed them his farm – again all orchards were netted.

POLAND APPLE INDUSTRY IN CRISIS

Hugh Campbell

Prof. Karen Theron, senior navorser by die Departement Hortologie aan die Universiteit van Stellenbosch, gee haar indrukke:

“Hulle lê baie klem op klimaatsverandering en die impak wat dit op hul produksiesisteme gaan hê. Só, doen hulle byvoorbeeld baie werk oor die impak van nette op boorde. Plat nette vs gegewelde nette. Weens klimaatstoestande het hulle amper nie meer ‘n keuse nie en dit is ‘n konstruksietema wat al outomaties deel van is van nuwe aanplantings. Hulle persepsie oor boomkwaliteit was ook interessant. Hulle sukkel blykbaar om geskikte bome uit hul kwekerye te kry, wat sommige produsente daartoe noop om self hul eie bome te kweek. Weens swak grondkwaliteit soek hulle natuurlik groeikragtige onderstamme soos M9’s en M26’s. Die Aussies se produksie aspekte is hoogs gemeganiseerd en hulle boorde is ook uiters verbruikervriendelik.”

Dr. Piet Stassen, ARC Infruittec-Nietvoorbij:

“Ek was veral beïndruk met wat die Australiërs in ‘n kort tyd vermag het - om boordeffektiwiteit en –produktiewiteit te verhoog. Een van Apple and Pear Australia Ltd. se inisiatiewe was die ‘’Future Orchard®’’ projek waaraan meeste produsente deelneem om nuutste inligting te verkry en onderling uit te ruil asook kundigheid in te trek. Dit het meegebring dat meer

A group of six intrepid South Africans and one Zimbabwean under the leadership of Peter Dall, undertook a technical tour to the apple production areas of Poland, Bodensee (Germany), Switzerland and South Tyrol (Italy). This article will mostly focus on Poland.

Poland, the fourth largest producer of apples in the world and by far the largest producer of apples in Europe was in a state of shock when we arrived there in early October 2014. Many of the growers had lost their primary market over-night. The ban on imports of fruit and vegetables from EU Countries, Norway and Australia imposed by Russia meant that Polish growers had to find alternative markets for their 2014 apple crop estimated at 3,5 million tons as around 70% of their fresh apples (50% of the production processed) were traditionally marketed in Russia. The main apple growing area in Poland around Skierniewice is basically very flat and is a patchwork of production blocks of 10 hectares. The average farm size of an apple producer is 10 hectares with no farms greater than 50 hectares in size. About one third of the apple production is seen to be highly productive producing around 80 tons per hectare with

27

an average fruit size of in excess of 80mm. The general orchard design was similar to what one saw in South Tyrol and Germany. We visited numerous brand new, state of the art packsheds paid for by 75% subsidies (EU and Polish Government). These cooperative packsheds supported around 350 hectares of production and had packaging and storage capacity (with DCA) way beyond the present demand implying that there is huge scope for expansion.


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intensiewe boorde met sagter, kalmer dra-eenhede onwikkel is. Meegaande figuur verduidelik die ontwikkeling miskien die beste. Hulle het ook soos ons meer groeikragtige onderstamme verkies (MM106) en geleidelik beweeg na M26. Die laaste paar jaar word nuwe appelaanplantings toenemend op M9 onderstamme gemaak. Bome is nader gespasieer as sentrale leiers, bi- en self trileiersisteme. Die 1:3 verhouding van draereenhede tot leier het plek gemaak vir 1:4. Onderste takke word gebuig maar daarna word die drag gebruik om alles in beheer te hou. Alle boorde is onder net en nie net om teen hael en voëls te beskerm maar ook om toestande te skep vir beter groeitoestande en om kwaliteit van vrugte te verbeter. Minimum snoei word toegepas. Boorde is ook ontwikkel om meganisasie in die hand te werk en selfs latere gebruik van robotte te akkomodeer.

Pieter de Wet, Larry Whitfield and Peter Dall outside one of the many new pack sheds with extensive cold storage facilities including DCA built in Poland (75% subsidy from the EU and Polish Government).

DO SHADE NETS EASE THE BURN OR DO THE Y BURN A HOLE THROUGH YOUR POCKET ▶▶ Observations and lessons learnt:

▶▶ Why did we do the work?

•

Sunburn is a major defect of apples produced for the fresh markets under the warm growing conditions in South African. Affected fruits are characterized by bleached or golden brown discoloured areas or, in its most severe form, necrosis of the peel. Since the visual appearance of the fruit plays an import part in the consumer preference, affected fruit are downgraded. In ‘Granny Smith’, which is very susceptible to sunburn and where even the slightest bleaching is visible, the pack-out may be as low as 40% (personal communication: Two-a-Day technical team).

•

• •

•

• • • • •

One needs to diversify ones markets. It is very dangerous to rely on one market – no matter how successful one has been in the past. In a South African context, the need for access to a diversity of markets is critical. One must plant the best and newest commercially successful varieties that are in demand in a variety of markets. We visited the biggest nursery in Poland producing in excess of one million apple trees where the main varieties being made were focused on the Russian market and are not varieties demanded in Western Europe and other markets. One must always produce top quality fruit. Good quality fruit is always easier to sell. Often we require major catastrophes to catalyse change. After the 1987 freeze Poland lost 30% of their trees to winter damage. This created the opportunity to establish high density orchards on M9 Rootstock which helped the industry greatly. We need to be proactive and make the changes that are required timeously. Virtually all the apple plantings viewed in the countries visited were high density plantings (3,000 and more trees / hectare) on M9 rootstock. The fruit size, precocity and tree size benefits of M9 are very evident. South Africa needs to select the right apple rootstocks and develop these as fast as possible. We need to select no more than three main rootstocks. Mechanisation and the use of harvesting platforms. Self-propelled platforms were seen on all operations Orchard floor management. Orchards are designed to accommodate machinery and are therefore very level allowing for platforms and spray rigs to spay at 8 – 10 km/h. Tree height is at 100 – 120% of row width. Platforms have allowed for the optimisation of tree height. Hail and shade netting. The general trend is to cover orchards for hail. All structures viewed were able to open and the structures were rather over designed than under-designed. Subsidies are not always good. They often over-capitalise in one area at the expense of another.

Sunburn is caused by high light levels and high fruit peel temperatures. Sunburn browning occurs at a peel temperature of 48 ºC while 10 minutes above 50 ºC is enough to kill peel cells resulting in necrosis. These seem like very high temperatures, but bear in mind that radiant heating may increase the fruit surface temperature by up to 16 ºC above air temperature. Shade nets decrease sunburn by decreasing the light exposure and thereby also the radiant heating of the fruit peel. This makes shade netting the most effective means to reduce sunburn on apples.

•

Adam Lajitjé a large Polish farmer who farms on 50ha and vice President of the Coop in a young apple block.

Population: 38 million people Annual rainfall: 500-600mm Poland 4th largest apple producer in world Poland - largest apple producer in Europe 2013 apple production: 3m tons 2014 apple estimate: 3,5m tons Processing apples: +- 50% 2013 exports: 70% of fresh apples to Russia (1m tons) Main varieties: Idared, Jonagold sports, Ligol (Polish variety), Szampion (Czech variety)

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3Dutoit Agri

Population: 49 million people Annual rainfall: 500-2500mm South Africa 16th largest apple producer in the world Not applicable

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•

1HORTGRO Science

2Two-a-Day Technical Dept.

An example of sunburned apples produced without shade netting and apples that were protected by netting.

South african apple production: • • •

Daan Brink1,2, Willie Kotze1,3 Wiehann Steyn1

In 2007, Two-a-Day Pty Ltd and Vegtech initiated a project to evaluate the production of different apple cultivars under shade nets in the Elgin, Grabouw, Vyeboom, Villiersdorp (EGVV) area. Funding for the project was obtained from HORTGRO Science. Different coloured nets were used in the trials; however, we here only present the effects of the netted strips (nets) to uncovered (control) strips due to unsuitable trial design and inconsistent effects obtained for the different colour nets.

Poland apple production: • • • • • • • •

Findings of a study in the EGVV on the use of shade netting to reduce sunburn in apple.

▶▶ What did we do?

▶▶ What did we find? ‘Granny Smith’

Full-bearing ‘Granny Smith’, ‘Cripps’ Red’, ‘Cripps’ Pink’ and ‘Fuji’ orchards were selected in the EGVV area. Alternating double rows of ‘Granny Smith’ on MM109, ‘Cripps Red’ on M25 and ‘Cripps’ Pink’ on M25 were covered in an orchard of producer (6), while alternating double rows of ‘Granny Smith’ and ‘Fuji’ on M793 were covered in an orchard of producer (66). ‘Fuji’ trees on a M25 were also covered at producer (41). An area of approximately 0.5 ha was covered with horizontal nets. Adjacent uncovered trees served as control. There were at least 5 replicates for each treatment. Data were collected only from central trees under each strip.

and alternate bearing in the last season resulted in yield losses under the nets. Although not assessed, the decrease in yield was possibly due to reduced flower bud development. Previous research has shown that ‘Fuji’ shows a very strong growth response to netting (Smit, 2007) and this may have a detrimental effect on both fruit red colour and yield regularity.

Fig. 1 shows that the nets substantially reduced the incidence of sunburn in ‘Granny Smith’. On average, sunburn at the ‘Granny Smith’ (6) site was reduced by 25% per annum over a 4 year period. At the Granny Smith (66) site, sunburn was reduced to lesser extent due to intermittent net coverage. The decrease in sunburn was directly reflected in a considerable increase and decrease in the percentage class 1 and 3 fruit, respectively (Fig. 2). The average yield for netted ‘Granny Smith’ was not affected compared to the uncovered strips (Fig. 3).

‘Cripp’s Red’, ‘Cripp’s Pink’ and ‘Fuji’ Netting almost completely eliminated sunburn in ‘Cripp’s Red’ and ‘Cripp’s Pink’ and reduced sunburn by ±10% in ‘Fuji’ on average (Fig.1). On the downside though, the nets also decreased fruit red colour resulting in a large increase in the percentage of poorly coloured fruit (Fig. 4). There was a trend for average yields of ‘Cripp’s Red’ and ‘Cripp’s Pink’ to increase under the nets although these increases were not statistically significant (Fig. 3). The apparent increase in yield can be ascribed to an increase in tree bearing area under the nets due to an increase in shoot growth. The effect on ‘Fuji’ yield and pack out was variable over the different seasons

CLASS 1

Vigour control was adjusted under the nets, but irrigation, nutrition and all other orchard practices were managed the same as the control. This is not ideal since netting affects irrigation and nutritional demands and also affects fruit set, therefore requiring adjustments in thinning programmes. Pearl, white, yellow and red nets were supplied by Vegtech while Knittex supplied a blue net. The nets were all classified as 20% shade net, which means that 20% of the area covered by the net consists of the net material; the amount of light absorbed by the nets differs based on the absorbance characteristics of the net material, i.e. a 20% black net absorbs more light than a 20% white net. Please refer to the suppliers for specifications on the different nets.

Fig. 2 - The class distribution of the different cultivars as affected by the treatments.

80 70 60 50 40 30 20 10 t/ha

Granny Smith (6) ****

Cripps’ Red (6) **

Fuji (41)*

Fuji (66)*

Cripps’ Pink (6)****


Granny Smith (66) **


Fuji (41)*

Fuji (66)*





Fuji (41)*

Fuji (66)*


Nets

Control

30 25

CLASS 2

20

Fig. 1 - Sunburn as percentage of all the fruit on the tree.

15 10 5 0 t/ha

30 25 20

CLASS 3

40 35 30 25 20 15 10 5 0 %




Fuji (41)*

Fuji (66)*


10 5 0 t/ha

Nets

Control

(#) Indicates the site number. *Number of * indicates the numbers of years of data for each orchard that were available for data analysis.

(#) Indicates the site number. * Number of * indicates the numbers of years of data for each orchard that were available for data analysis.

30

31



15

•

In ‘Cripp’s Pink’, the slight decrease in sunburn (± 6 %) did not compensate for the loss in red colour (± 20 %) despite the slight increase in yield observed in some years. More class 2 and 3 and less class 1 were produced (Fig. 2). In ‘Cripp’s Red’, the decrease in fruit with adequate red colour was evened out by the reduction in sunburn. Hence, due to the slight increase in yield, nets

Fig. 3 - Fruit with inadequate red colour as percentage of all the fruit on the tree. 50 45 40 35 30 25 20 15 10 5 0 %

increased the class 1 fruit produced. In ‘Cripp’s Pink’, the slight decrease in sunburn (± 6 %) did not compensate for the loss in red colour (± 20 %) despite the slight increase in yield observed in some years. More class 2 and 3 and less class 1 were produced (Fig. 2). In ‘Cripp’s Red’, the decrease in fruit with adequate red colour was evened out by the reduction in sunburn. Hence, due to the slight increase in yield, nets increased the class 1 fruit produced.

•

The reduction in sunburn in less sunburn-sensitive and in red and blushed cultivars does not justify the cost of netting. The economics may improve for orchards on dwarfing rootstocks like M9 or G222 and with better coloured strains of blushed cultivars.

•

It’s not a good idea to cover orchards on vigorous rootstocks under nets except maybe if the trees for some reason are stunted or if you like pruning very much and have a mountain of growth retardants in the chemical store. Whereas the growth response under nets may be a benefit in the case of trees on dwarfing rootstocks, on vigorous rootstocks it results in poor colour in blushed cultivars, decrease fruit quality in general and may also negatively affect total yield and the regularity of cropping.

▶▶ So what’s the net result? Cripps’ Red (6) ** Nets

Fuji (41)***

Fuji (66)**


Control


•

It makes economic sense to cover new ‘Granny Smith’ plantings under nets. The reduction in sunburn alone justifies the considerable cost of netting.

Older ‘Granny Smith’ orchards may also benefit from a reduction in sunburn under nets. Nets may also invigorate worn out ‘Granny Smith’ orchards, resulting in a potential yield increase.

•

•

•

•

The project did not answer the question of whether coloured nets are better than the durable and most commonly used black nets. However, such research is difficult due to the effect of coloured nets on both the light spectrum and quantity of light that is allowed through.

may be an aid when planting precocious dwarfing rootstocks. Research under local conditions is needed so that informed decisions that consider all potential benefits and drawbacks of netting can be made. Dr Simon Middleton of the Queensland Department of Agriculture, Fisheries and Forestry at Stanthorpe, Australia, did some great work on netting. Interested readers are referred to a summary of his work published in the Compact Fruit Tree as Middleton, S. & McWaters, A. 2002. Hail netting of apple orchards – Australian experience. The Compact Fruit Tree 35 (2): 51-55. The article can be accessed on the web at: http:// www.virtualorchard.net/idfta/cft/2002/april/ page51.pdf Those who believe that local is lekker and are not afraid of thick books can request Armand Smit’s MSc thesis from the authors of this article. Armand’s study was conducted under the supervision of Prof Stephanie Midgley at Stellenbosch University. Smit, A. 2007. Apple tree and fruit responses to shade netting. MScAgric, Stellenbosch University, Stellenbosch.

▶▶ Further net benefits not assessed in this study, but that should be part of the equation: It falls outside the scope of this study, but the economics of netting improves dramatically in hail-prone regions, especially for the most lucrative cultivars. This is a risk decision the producer takes together with his insurer and bank manager.

•

Apart from the obvious reduction in sunlight levels under nets, netting also increases humidity and lowers wind speeds. Hence, netting may decrease irrigation needs, allow spraying for pests and diseases when conditions outside are unsuitable and allow better drying of spray chemicals. Full enclosure of orchards– like the Oak Valley Orchard of the Future – may keep out some insect pests. A net covering provides some of the same physical benefits of a mulch layer, such as buffering soil temperature and decreasing evaporation of irrigation water from the soil.

•

The increase in growth in response to netting

Fig. 4 - The effect of netting on average yield of the different cultivars.

100 90 80 70 60 50 40 30 20 10 0 %

Granny Smith (6) **** Nets



Fuji (41)***

Fuji (66)**


Control


32

Fig 5: Airial view of the ‘Granny Smith’, ‘Cripps' Red’ and ‘Cripps' Pink’ net trial at site 6. Note that the control trees are fairly sparse.

Fig 6: Airial view of the ‘Fuji’ net trail at site 41. Note the volume, indicative of vigour, of the control trees.

33


•

R O O T S T O C K S F O R E A R LY N E C TA R I N E S A N D P L U M S I N A L O W CHILL REGION

Dr Piet Stassen, ARC Infruittec-Nietvoorbij: The South African stone fruit industry needs a variety of rootstocks to choose from because of the variability of soil textures, the presence of Criconemoides xenoplax, Meloidodogyne incognita and M. javanica, calcareous soils, high water tables during winter and spring as well as different climatic conditions. Stassen (2011) and Stassen and Reinten (2011) discussed some of the variables and how rootstocks can affect the performance of nectarine and plum trees under such conditions. The local rootstocks Kakamas seedling, Marianna, Maridon and Royal seedling are still widely used because of their ease of propagation at lower cost. All these rootstocks have their limitations that can result in decreased

production, a negative effect on fruit size and even the die-back of trees under certain conditions. Imported rootstocks from different breeding programmes (Reighard and Loreti, 2008) are available. However, their ability to optimise scion performance under local conditions must be determined. For this purpose, 16 trials were planted in different soil and climatic conditions. This paper discusses rootstock performance in terms of yield, yield efficiency, fruit mass and trunk circumference of nectarine and plum trees at four of these sites.

▶▶ Materials and methods The first two trials are at the same location in the northern fruit region (S 24º25’63’’, E 28º35’79’’) on a commercial farm (Bufland) in the Mpumalanga Province and were

34

‘African Delight’ plum trees on 10 rootstocks were planted during June 2008 as part of a commercial orchard on the farm Elkana in the Berg River valley, Western Cape Province (S 33º50’ 20.60’’, E 18º 57’ 57.60’’ and altitude, 138m).

▶▶ Results and discussion 1.

‘African Delight’ plum trees on 11 rootstocks were planted during 2008 as part of a commercial orchard in the Little Karoo on the farm Sonskyn (S 33º51’ 3.90’’, E 19º59’19.80’’ and altitude, 157m). Soil is sandy (89.4 % fine sand, 7.1% silt and 3.5% clay) with a pH [KCl] 7.6 and Richardson chilling units during the experimental period varied between 350

2008 nectarine planting at Bufland (Table 1, Fig.1 Cumulative yield of trees on Flordaguard is the highest, but does not differ significantly from that on Atlas. Fruit weight of trees on Flordaguard, Cadaman and Atlas are not statistically different, but significantly better than on Tsukuba 5, SAPO 778 seedling and Kakamas seedling. The Fruit weight of trees on Flordaguard are 14% better than on Kakamas seedling. The cumulative yield over four harvests are double for trees on

▶▶ Table 1 Average yield values, fruit mass and trunk circumferences for ’Alpine’ nectarines on eight rootstocks after four harvest seasons at Bufland, 2008 planting. Rootstock

Average yield (kg/tree)

Ave yield efficiency** (kg/cm2)

Cum. yield (t/ha)

Flordaguard

5.00 a

0.1437 a

52.54 a

99.42 a

Cadaman

4.35 ab

0.1077 c

41.54 bc

94.65 ab

267.94 a

Atlas

4.23 bc

0.1379 ab

46.85 ab

95.59 ab

247.44 bc

Guardian

3.59 cd

0.1149 c

34.11 cde

90.42 bc

243.00 bc

Tsukuba 5

3.55 cd

0.1235 abc

39.47 bcd

87.49 c

248.93 abc

SAPO 778*

3.46 de

0.1150 c

32.22 de

87.80 c

240.11 c

GF 677

2.95 de

0.1251 abc

29.07 e

90.61 bc

218.77 d

Kakamas*

2.80 e

0.1191 bc

26.48 e

85.55 c

214.75 d

0.0255

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