Mandrin fruits showed a reduction in juice acidity during storage at room temperature (25 C). Concerning changes in vitamin âCâ during storage. Bilisli et al.
J. Agric. Sci. Mansoura Univ., 25 (12): 8027 - 8037, 2000.
EFFECT OF CALCIUM AND POTASSIUM FOLIAR APPLICATION ON LEAVES NUTRIENTS CONTENT, QUALITY and STORAGE LIFE OF CITRUS (WASHINGTON NAVEL ORANGE) UNDER DRIP IRRIGATION IN CLAY SOIL El Shobaky, M.A.* and M.R. Mohamed** * Horticulture. Res. Ins, Agric. Res. Center, Giza, Egypt. ** Plant Nutrition Dept., Soil, Water and Environment. Res. Ins., Agric. Res. Center, Giza, Egypt.
ABSTRACT This study was carried out in seasons of 1998 and 1999 on Washington Navel Orange trees grown at Dakahlia Governorate, Egypt. The obtained data indicated that spraying potassium 2% (solupotasse) increased significantly fruit weight, juice volume and T.S.S but acidity and ability to storage is decreased. Calcium (sequestrated calcium) applications is more effective to reduce post-harvest losses of fruit and hold on fruits maintaining acceptable quality under ambient conditions longer time prolonging the marketability and storage shelf-life of the treated fruits. Spraying calcium and potassium together increased fruits quality and storage ability compared with the control and potassium treatments. For that potassium is important to increase fruit weight and crops but calcium very vitail and effective factor to maintaining better fruit quality for longer time under room temperature. K application gave a significant increase in N% in leaves at all stages compared with control in both seasons, while resulted in a significant decrease on P, K and Ca% in most stages. Ca application gave a significant increase in Ca% in leaves at all stages, but N% increased in second and third stages in both seasons. N, P, K and Ca% were increased significantly compared with control under K + Ca application in both seasons.
INTRODUCTION In Egypt, citrus (Washington Navel orange) is one of the most important fruits. It is considered the first crop from the different citrus cultivars grown in Egypt, Washington Navel orange is one of the leading varieties, for local market and especially export. The improvement of fruit quality and shelf life of Washington Navel orange are of the most important objective in Egypt. in this study trees put under drip irrigation system. Several practices have been tried to achieve this aim by foliar applications of potassium and calcium at preharvest. Potassium appears to be necessary for the synthesis of amino acids. It differs from carbon, hydrogen, oxygen and other essential elements in that. It is not a constituent of the manufactured compounds or a part of any living tissue. Nevertheless, plants don’t grow in the absence of potassium (El-Boray et al. 1996; Edmond et al. 1975).
El-Shobaky, M.A. and M.R. Mohamed A number of experiments have reported a positive correlation between sizes and percent K in leaves (Chapman and Brown, 1950 and Jone and Embleton, 1956). K content of citrus leaves can be increased markedly by using foliar applications of K NO3 solution and that the absorbed K is readily translocated to new growth (Page et al., 1962). Calcium is one of the pre-harvested or post-harvest treatments which has been widely used in several studies since 1956 to control many of physiological and chemical changes affecting quality characteristics of fruits. The major role of Ca2+ is in the formation of the cell wall structure where it is fixed in soluble form giving support to the skeleton of the fruit. Most of the calcium introduced into fruit tissue accumulates in the cell wall-middle lamella region, where it forms ionic bridges within and between pectic polymers, conferring rigidity to cell wall (Burns and Pressey, 1987 and Poovaiah, 1993). The present study aimed at clarifying the effect of potassium and calcium on fruit weight, quality, shelf-life and concentration of these nutrients in leaves of Washington Navel orange.
MATERIALS AND METHODS This investigation was carried out during two seasons of 1998 and 1999 to study the effect of foliar applications of K+, Ca2+ and K+ + Ca2+ on fruit quality, shelf life and mineral composition of leaves on Washington Navel orange under drip irrigation in clay soil. This study was performed on 12 years-old orange growing in private orchard at Miniet Samonod, Dakahlia Governorate, Egypt. The trees were under drip irrigation system in clay soil. Trees were spaced at 5 5 meters and received the cultural practices commonly adopted in that area. The selected trees were almost uniform as possible concerning vigor and free from diseases. During two seasons 48 trees were selected and arranged in a randomized block design, 3 replicates in each replicate, 4 trees were chosen at random to receive one of the 3 practices shown in Table (1). Table (1): Various practices applied. No
Practices used
1
Control
2*
Calcium at 1%
3**
Potassium at 2%
4
Calcium + potassium at the same concentration
* Ca (10% Ethylene diamine tetra acetate (sequestrated calcium). ** K (50% potassium oxide (K2O) water soluble (solu. Potasse).
Notes: 1- Control was sprayed with tap water. 2- Ca2+ was sprayed at 3 dates.
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J. Agric. Sci. Mansoura Univ., 25 (12), December, 2000. (A) before bloom. (B) after fruit set. (C) at verasion stage. 3K+ was sprayed at 3 dates. (A) before bloom. (B) after fruit set. (C) at verasion stage. 4- Ca2+ + K+ by the same concentration and dates.
I. Determination at harvest: When the fruits reached to the harvesting stage, a sample of about 10 fruits was taken per replicate and the following characteristics were determined. 1- Average fruit weight (gm). 2- Average fruit peel weight (gm) and thickness (mm). 3- Juice volume (cm3). 4- Total soluble solids %. 5- Total acidity %. 6- T.S.S/acid ratio. 7- Vitamin C. II. Determination at storage: For each determination time. Each replicate was 10 fruits put in carton boxes (each contain about 2.5-3.5 KGS.) and held at room conditions of about 18-20 C and about 85-90 relative humidity for 60 days. Samples in four boxes were taken in each sampling period (15 days interval) to be subjected to the following determinations: 1- Decay percentage due to diseases (gm). 2- Fruit weight losses percentage (gm). 3- Total loss (Decay + loss in weight). 4- Average fruit peel weight (gm) and thickness (mm). 5- Juice volume (cm3). 6- Total soluble solids %. 7- Total acidity %. 8- T.S.S/acid ration. 9- Vitamin C. Before growing season the experimental units irrigated two times with surface irrigation to leach the soil using Nile water. The drip irrigation from well. Each row of trees between to pipe lines. Each tree received 16/L/h from 4 valve. In winter tree received 16/L/h/daily and in summer tree received 48/L/3h/daily. Table (2): Some chemical analysis of irrigation and drainage water of the farm. Sample Irrigation
E.c dS/m 0.8
Soluble anions meq/L Co 3 0.2
HCo 3 4.8
Cl3.0
Soluble cations meq/L
SO 4 0.00
8029
Ca++
Mg++
K+
Na+
2.6
2.0
0.27
3.13
El-Shobaky, M.A. and M.R. Mohamed Drainage
4.4
0.00
10.0
31.2
2.8
20.0
4.0
0.27
19.73
Soil samples were collected from profile to represent: 0-30, 30-60 and 60-120 cm. Irrigation and drainage water sample were collected before seasons. Leaves samples were collected at different three physiological stage each one was taken after 7 days of spraying. The chemical analysis of all samples leaves, water and soils were done according to Black (1965). The obtained data were statistically analyzed according to Snedecro and Cochran (1967). But the obtained data of N, P, K and Ca % of leaves were statistically analyzed according to Gomez and Gomez (1984).
RESULTS AND DISCUSSION (A) Effect of K application on mineral composition of leaves: Data of Table (4) indicated that, N% was increased significantly compared with control at all three physiological stages in both seasons as influenced by K+ application. P and K% were reduced significantly compared with control at second and third stages in both seasons, while increased significantly at first stage in both seasons. Ca% was decreased significantly compared with control at all three physiological stages in both seasons. This result agree with those obtained by Johanson et al. (1998) on pears leaf Ca concentration. (B) Effect of Ca application on mineral composition of leaves: Data of Table (4) show that N% was increased significantly at second and third stages, but decreased significantly in first stage in both seasons compared with control. P% increased significantly compared with control in first stage, but reduced significantly at second and third stages in both seasons. K% was reduced significantly in first and third stages compared with control, while increased significantly at second stage in both seasons. Ca% was increased significantly in most stages in both seasons except in 1999 season where it decrease at second stage compared with control. (C) Effect of K+Ca application on mineral composition of leaves: Data of Table (4) illustrated that, N and K% were increased significantly at all three physiological stages compared with control in both seasons. P% was increased significantly at first and second stages, while reduced significantly at third stage in both seasons compared with control. On the other hand Ca% did not show any trend compared with control in both seasons at all stages. I. Fruit quality at harvest: Fruit weight: The average fruit weight was greatly increased significantly by spraying K+ and K+ + Ca2+ (Table 4). The values are 327.0 to 326.1 and 315 to 310.2 gm. in the two seasons. The lowest fruit weight, however, was obtained from
8030
J. Agric. Sci. Mansoura Univ., 25 (12), December, 2000. control untreated ones. Such results are in line with Embleton and Jones (1972) on Marsh grape fruit, Lotfy et al. (1990) on Guava and EL-Shobky (1995) on Thompson seedless grape. Peel weight and peel thickness: Data presented in Table (5) reveal an obvious significant increased in peel weight and thickness of fruit sprayed with calcium if compared with other treatments and control in two seasons under study. Fruits peel thickness and peel weight as affected by calcium of both seasons ranged between 4.32 to 4.47 mm and 78.9 to 80.73 gm for Navel fruits. The corresponding values for the control were 3.1 to 3.1 mm and 40.47 to 39.47 gm. These results agree with the finding of Helal (1999) on citrus. 3
8031
El-Shobaky, M.A. and M.R. Mohamed 4+5
8032
J. Agric. Sci. Mansoura Univ., 25 (12), December, 2000. Juice volume, T.S.S, acidity and T.S.S/acid ratio: Concerning fruit juice statistical analysis showed significant differences. K+ gives high value compared with the other treatments and control in the two seasons. With respect to the effect of K+ on T.S.S percentage and T.S.S/acid ratio. Data of Tables (6 and 7) indicate that K+, significantly increased the value of T.S.S and decreased the value of acidity compared with the control. Vitamin “C”: From Table (7) it is clear that vitamin “C” content was affected by spraying with calcium and calcium + Potassium. The spraying with calcium more effective and significantly increased vitamin “C” content in the juice fruits in the two seasons of the study. These results agree with Helal (1999). II. Fruit quality at post-harvest during storage: Concerning changes in peel thickness and weight during storage period showed in general, a gradual decrease as the storage period advanced. Studies on juice volume behaviour of stored fruits indicated that an obvious decrease in juice volume with strong time. Results of changes in chemical fruit characteristics during storage period till 60 days under room conditions clearly indicated that pre-harvest treatments of Navel orange with K+ and K + Ca solutions increase T.S.S and T.S.S/acid ratio if compared with control. As for juice acidity behaviour during period the results of EL-Gazawy (1973) with stored lime fruits and Angadi and Krishnaurthy (1992) with Coorg Mandrin fruits showed a reduction in juice acidity during storage at room temperature (25 C). Concerning changes in vitamin “C” during storage. Bilisli et al. (1970) working with 2 cvs. of lemon and found that vitamin “C” in juice was decreased during storage at room temperature. They added that the decrease is due to an increase in “VC” oxidation in fruit juice with the increasing of storage temperature. The pre-harvest Ca2+ application on trees may be succeeded to delay fruit ripening and increase resistance to storage disorders, improve storage quality and prolong shelf-life of the fruits (Mulas et al., 1995; Pathmanaban et al., 1995 and Droby et al., 1997). As for changes in fruit weight loss and decay EL-Nawam (1991) with Navel oranges and Ahamed (1993) with Balady Mandarin reported that fruit weight loss significantly increased as the storage period advanced. Salem and EL-Khoreiby (1991) with March seedless grape fruit trees found that pre harvest sprays with 1% Ca have an effect similar to that of decreasing storage temperature on lowering fruit weight losses and decay percentage during storage. Data in Table (8) are in harmony with the present result. In this study K+ give high losses in weight and decay if compared with control.
6+7
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El-Shobaky, M.A. and M.R. Mohamed
8
8034
J. Agric. Sci. Mansoura Univ., 25 (12), December, 2000.
REFERENCES Ahmed, F.G. (1993). Effect of pre storage treatments on physico chemical changes of Balady mandarin fruits (Citrus reticulata L.) during cold storage. M. Sc. Thesis, Faculty of Agric. Alex. Univ. Angadi, G.S. and S. Krishnaurthy (1992). Studies on storage of Coorg Mandrin (Citrus reticulata Blanco). South Indian Hort., 40 (5): 289-292. Bilisli, A.; A. Ayanoglu and N. Baykent (1970). Vitamin “C” losses from stored lemons. Yalova Bachekulturderi Arastirmava Egitin uerkezi Dergisi, 3 (3): 45-49. (Hort. Abst., 42: 23261). Black, C.A. (Ed) (1965). Methods of Soil Analysis. Part 2, No. 9, Amer. Soc. Agron. Madison, Wisc. USA. Burns, J.K. and R. Pressey (1987). Ca in cell wall of ripening tomato and Peach. J. Amer. Soc. Hort. Sci., 112: 783-787. Chapma, H.D. and S.M. Brown (1950). Analysis of orange leaves for diagnosing nutrient status with reference to potassium. Hilgardia, 19: 501-510. Droby, S.; M.E. Wisniewski; L. Chen; B. Weiss; D. Touitou; Y. Eilam and E. Chalutz (1997). Influence of CaCl2 on penicillium digitatum, grapefruit peel tissue and biocontrol activity of Pichia guilliermondii. Phytopathology, 87 (3): 310-315. Edmond, J.B.; T.L. Senn; F.S. Andrews and R.G. Halfacre (1975). The essential elements. Fundamentals of Horticulture, Mc. Graw-H. 11 Book company, 4th ed., 131 pp. El-Boray, M.S., Fahmy, M.M., Iraqi, M.A., Lo’ay, A.A. (1996). Effect of potassium soil and foliar fertilization on leaf potassium content, yield and berry quality of Thompson seedless grape. J. Agric. Sci. Mansoura Univ. 21, 1153-1162. EL-Gassawy, A.G. (1973). Physiological studies on lime and lemon fruits during handling, Packing and storage. M. Sc. Thesis, Faculty of Agric., Ain Shams Univ., Egypt. EL-Nawam, S.M. (1991). Rind creasing and quality of Washington Navel orange fruit in relation to application with some growth substances M. Sc. Thesis, Faculty of Agric., Alex. Univ., Egypt. EL-Shobky, M.A. (1995). Storage life of Thompson seedless grapes as affected by some field practices. Ph. D. Thesis, Fac. of Agric., Mansoura Univ., A.R.E. Embleton, T.W. and W.W. Jones (1972). Correction of potassium deficiency in grape fruit. The California Citograph, 227-231. Gomez, K.A. and A.A. Gomez (1984). Statistical procedures for Agriculture Research “John Willy and Sons, Inc. New York. Helal, E.M. (1999). Effect of pre-Harvest and Pot-Harvest treatments on citrus fruit contents and the susceptibility to storage. Ph. D. Thesis, Fac. of Agric., Mansoura Univ., A.R.E. Johnson, D.S.; T.J. Samuelson; K. Pearson and J. Taylor (1998). Effects of soil applications of potassium sulphate on the mineral composition and eating quality of stored ‘Conference’ and ‘Doyenne’ du ‘Comice’ Pears.
8035
El-Shobaky, M.A. and M.R. Mohamed Hort. Res. Int., East Malling, Kent ME 196 BJ, UK (Journal of Hort. Science & Bio-technology 73 (2): 151-157. Jone, W.W. and T.W. Embleton (1956). The relation of Potassium to fruit size in oranges. Better crops with Plant Food, 40 (4): 22-25. Lotfy, H.O.; Ikram Saad EL-Din and M.E. Said (1990). Effect of Potassium sulphate foliar application on guava trees. Agric. Rec. Rev. Cairo, 68(5): 949. Mulas, M.; M. Schirra; I. Chessa; A. Ait and M. EL-Otmani (1995). Responses of March seedless grape fruit to pre-storage Ca Cl2 treatments with or without fungicides. Post harvest physiological, Pathology and Technologies for Horticultural commodities; Resent Advances Proceedings of an International symposium held at Agadir, Morocc, 1612 January, 51-56. Page, A.L.; J.P. Martin and T.J. Gange (1962). Foliar absorption and translocation of potassium by citrus. Amer.Soc.Hort. Sci.; 82: 165-171. Pathmanaban, G.; M. Nagarajan; K. Manian and K. Annamalianathan (1995). Effect of used calcium salts on post-harvest preservation in fruits. Madras Agricultural Journal, 82, (1); 47-50. Poovaiah, B.W. (1993). Biochemical and Molecular aspects of calcium action. Acta. Hort., 326: 139-147. Salem, A.T. and A.M.K. Khoreiby (1991). Effect of pre-harvest sprays of calcium chloride and storage temperature on quality and decay percentage of grape fruit. Bulletin of Fac. of Agric. Cairo Univ., 42 (4): 1285-1298. Sendecor, G.W. and W.G. Gochran (1967). Statistical methods, 6th ed. Iowa State Univ., Press, Ames. 395.
ت أثير ال رش بالكالس يوم والبوتاس يوم عل ى محت وى األوراق م ن العناص ر اللغذائي ة والجودة ومدة تخزين الثمار فى الموالح (البرتقال أبو سرة) تحت ظروف الرى بالتنقيط فى أرض طينية. محمد عاطف الشوبكى -محمد رضا عبد الھادى محمد معھد بحوث البساتين -قسم تغذية النبات -معھد بحوث األراضى والمياه والبيئة مركز البحوث الزراعية -الجيزة -مصر. أجرى ھذا البحث لدراسة تأثير الرش بالكالسيوم (شيالت الكالسيوم) البوتاسيوم (سولو بوتاسيوم) على صفات الجودة ومدة تخزين البرتقال أبو سرة فى أرض طينية تروى بنظام الرى بالتنقيط وذلك خالل عام ١٩٩٩ ،١٩٩٨وكانت التركيزات المستخدمة ھى %٢ ،%١على التوالى لكل عنصر. وقد وجد أن الرش بالبوتاسيوم أدى إلى زيادة معنوية فى وزن الثمار وحجم العصير ونسبة المواد الصلبة الذائبة وتقليل الحموضة لكنه أدى إلى تقليل من حياة الثمار أثناء التخزين على درجة حرارة الغرفة. أما الرش بالكالسيوم فقد أدى إلى زيادة معنوية فى سمك ووزن قشرة الثمار وكذلك زيادة نسبة فيتامين ج إلى جانب له دور ھام فى تقليل الفقد فى الوزن وزيادة مدة حياة الثمار أثناء التخزين على درجة حرارة الغرفة .أما الرش بالكالسيوم والبوتاسيوم معا ً أدى إلى زيادة فى وزن الثمار وحجم العصير ونسبة المواد الصلبة الذائبة وفيتامين ج مقارنة بالكنترول -كذلك أدى إلى زيادة معنوية فى سمك القشرة ووزنھا مقارنة بالكنترول والبوتاسيوم فقط وعلى ھذا األساس يعتبر البوتاسيوم عامل ھام فى زيادة المحصول ولكن يعتبر الكالسيوم عامل ھام جدا ً فى زيادة مدة تداول الثمار لتسويقھا فى السوق المحلى والتصدير.
8036
J. Agric. Sci. Mansoura Univ., 25 (12), December, 2000. أدى التسميد بالبوتاسيوم إلى زيادة معنوية فى تركيز النتروجين كنسبة مئوية فى األوراق فى كل المراحل بالمقارنة مع الكنترول ،بينما أدى إلى نقص معنوى فى كل من الفوسفور والبوتاسيوم والكالسيوم فى معظم المراحل .كما أدى إضافة الكالسيوم إلى زيادة تركيز الكالسيوم فى األوراق كنسبة مئوية فى جميع المراحل فى كل من الموسمين وزيادة النتروجين فى المرحلة الثانية والثالثة .أما إضافة الكالسيوم والبوتاسيوم معا ً أدى إلى زيادة واضحة فى تركيز كل العناصر كنسبة مئوية فى األوراق فى كل من الموسمين فى معظم المراحل.
8037
J. Agric. Sci. Mansoura Univ., 25 (12): 8027 - 8037, 2000.
Table (3): some chemical analysis of the soil profile. Sample Ec dS/m in depth 1:5 extract
T.S.S in 1:5 extract
pH 1:2.5
Soluble amions meq/100 g Soluble cations meq/100 g Co 3
Hco 3
Cl-
Ca++
Mg++
K+
Na+
So 4
Available nutrients N ppm P ppm K ppm
Ca %
0-30
1.7
0.054
7.9
0.00
0.5
0.12
0.23
0.2
0.1
0.03
0.5
38
12
280
2.66
30-60
3.3
0.106
8.0
0.00
1.2
0.21
0.24
0.2
0.1
0.02
1.36
33
11
270
2.66
60-120
3.4
0.109
8.0
0.00
1.2
0.18
0.32
0.3
0.3
0.08
1.02
23
10
251
2.66
* T.S.S = Total soluble salts
El-Shobaky, M.A. and M.R. Mohamed
Table (4): Effect of Ca, K and Ca + K foliar application on mineral composition of leaves, and fruit weight at harvest time of fruit in 1998 and 1999 seasons. First Date before bloom 1998
Treatments
second date after fruit set
1999
1998
Third date at version stage
1999
1998
fruit weight (g)
1999
N%
P%
K%
Ca%
N%
P%
K%
Ca%
N%
P% K% Ca%
N%
P%
K%
Ca Ca% N% P% K% %
Ca N% P% K% % 1989 1999
2.45
0.11
1.50
2.20
2.33
0.11
1.36
2.10
2.10
0.16 1.50 2.85
1.94
0.15
1.50
2.75 2.17 0.23 1.79 1.80 2.17 0.21 1.75 1.75 223.0 220.0
Ca T2
2.07
0.13
1.10
2.60
2.17
0.12
1.09
2.60
2.25
0.14 1.80 3.87
2.21
0.10
1.86
3.68 2.60 0.08 1.75 3.60 2.49 0.07 1.72 3.43 278.3 275.2
K T3
2.60
0.20
1.50
1.80
2.59
0.17
1.68
1.75
2.40
0.10 1.40 2.65
2.36
0.11
1.42
2.68 2.75 0.07 1.55 1.77 2.64 0.07 1.50 0.50 327.0 320.1
K+Ca T4
2.90
0.23
1.50
2.10
2.91
0.22
1.51
2.03
2.80
0.21 1.57 2.87
2.92
0.21
1.59
2.70 2.88 0.08
L.S.D 0.05
0.15
0.006
0.23
0.16
0.05
0.06
0.06
0.13
0.20
0.019 0.19 0.11
0.07
0.015
0.08
0.12 0.14 0.009 0.08 0.12 0.07 0.20 0.10 0.27 2.31
1.8 1.85 2.77 0.06 1.77 1.81 315.0 310.2 2.33
Table (5): Effect of Ca2+, K+ and Ca2+ + K+ on peel weight and peel thickness during room storage in 1998 and 1999 seasons. Treatments
Peel weight (g) At harvest ---
Peel thickness (mm)
Period in days at room temp. 15
30 1998
1999
45
At harvest 60
Period in days at room temp.
---
15
30
45
60
1998
1999
1998
1999
1998
1999
1998
1999
1998
1999
1998
1999
1998
1999
1998
1999
1998
1999
Control
40.47
39.47
36.50
36.70 32.63 33.43 30.30
30.37
23.23
24.17
3.10
3.10
3.03
2.97
2.80
2.90
2.68
2.63
2.57
2.50
Ca
78.90
80.73
74.43
76.67 62.27 66.23 52.20
57.37
37.23
40.33
4.32
4.47
4.10
4.30
3.88
4.10
3.78
3.87
3.17
3.50
2
K
69.57
70.37
64.53
66.23 52.13 58.43 45.27
51.23
23.40
29.87
3.50
3.40
3.30
3.10
3.07
3.10
3.10
2.90
2.87
2.80
K + Ca
75.93
78.20
70.90
72.73 50.17 53.20 42.40
44.37
31.73
33.63
3.93
3.83
3.82
3.67
3.50
3.4
3.53
3.17
3.03
3.03
L.S.D 0.05
0.88
0.70
3.46
0.50
0.55
0.28
0.92
0.19
0.16
0.06
0.19
0.19
0.12
0.17
0.15
0.12
0.21
0.50
0.36
0.33
J. Agric. Sci. Mansoura Univ., 25 (12), December, 2000.
Table (6): Effect of Ca2+, K+ and Ca2+ + K+ on juice volume and T.S.S during room storage in 1998 and 1998 seasons. Juice volume (cm3) At harvest
T.S.S**
Period in days at room temp.
At harvest
Period in days at room temp.
Treatments
---
15
1998 1999 1998
30
45
60
---
1999
1998
1999
1998
1999
1998
1999
15
30
45
60
1998 1999 1998 1999 1998 1999 1998 1999 1998 1999
Control
80.0
85.0
71.0
76.0
66.3
67.3
60.7
66.0
61.0
63.0
11.23
11.27
12.37
11.80
12.33
12.47
12.73
12.60
13.10
13.03
Ca
111.0
108.0
105.0
104.0
98.0
99.3
90.3
92.7
88.3
90.0
11.57
12.13
12.90
12.57
13.17
12.70
13.30
13.30
13.73
13.90
K
118.3
120.3
108.3
112.3
103.0
108.7
101.0
102.0
96.0
100.0
12.67
12.73
13.67
13.43
13.67
13.60
13.77
13.90
14.70
14.70
K + Ca
115.0
113.0
106.0
111.0
103.0
106.3
89.7
95.3
88.0
92.0
12.40
12.20
12.70
12.73
13.33
12.77
13.77
13.07
13.63
13.67
L.S.D 0.05
1.91
1.91
2.23
1.91
1.53
1.29
1.37
1.10
1.91
1.73
0.49
0.40
0.65
0.43
0.46
0.37
0.24
0.48
0.31
0.23
** T.S.S = Total soluble solids
Table (7): Effect of Ca2+, K+ and Ca2+ + K+ on acidity, T.S.S/acid ratio and Vitamin “C” during room storage in 1998 and 1999 seasons. Treatments
Acidity
T.S.S/acid ratio
3
Vitamin C
At harvest period in days at room temp. --15 30 45 60 Cont. Ca K K + Ca
At harvest period in days at room temp. --15 30 45 60
At harvest period in days at room temp. --15 30 45 60
98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 98 99 0.980 0.972 0.916 0.901 0.895 0.872 0.861 0.854 0.854 0.832 11.45 11.60 13.50 13.10 14.44 14.76 15.50 15.66 40.33 39.10 37.38 35.60 34.48 32.20 33.78 30.37 30.62 29.37 13.7714.21 0.903 0.895 0.894 0.841 0.873 0.820 0.852 0.801 .0826 0.790 12.81 13.53 14.42 14.94 15.78 16.61 16.67 17.39 54.56 52.87 53.62 51.07 51.88 49.75 51.23 47.32 49.07 46.40 15.0915.49 0.900 0.892 0.890 0.882 0.871 0.864 0.825 0.822 .0816 0.810 14.07 14.27 15.35 15.23 16.69 16.92 18.01 18.15 51.15 49.33 47.37 45.77 45.79 45.60 43.72 41.97 41.57 40.63 15.6915.75 0.951 0.902 0.891 0.864 0.852 0.815 0.832 0.828 0.821 12.81 12.82 14.06 14.29 15.78 15.70 16.46 16.64 53.13 50.90 52.62 47.70 50.38 46.73 48.80 44.03 45.39 41.37 15.3415.98 0.963
L.S.D 0.010 0.003 0.007 0.002 0.007 0.004 0.006 0.005 0.009 0.004 0.43 0.47 0.77 0.45 0.48 0.47 0.71 0.53 0.51 0.30 1.20 0.41 0.76 1.26 0.33 0.63 0.45 1.88 1.02 0.75
0.05
El-Shobaky, M.A. and M.R. Mohamed
Table (8): Effect of Ca2+, K+ and Ca2+ + K+ on loss in weight, decay and total loss during room storage in 1998 and 1999 seasons. Loss in weight %
Decay %
Tot al loss %
Period in days at room temp.
Period in days at room temp.
Period in days at room temp.
15
30
45 1998
1999
60 1998
15
30
45
60
1999
1998
15
30
45
1999
1998
60
199
1999
1998
1999
1999
1998
1999
1998
1999
1998
1999
1998
1999
1999
1999
1998
1999
Control
7.20
8.23
9.13
10.60 15.72 17.60 22.27 23.87
0.00
0.00
8.40
7.60
14.60 15.37 22.83 23.17
7.20
8.23
17.53 18.20 30.32 32.97
45.1
47.04
Ca
5.14
6.17
7.60
0.00
0.00
0.00
0.00
5.14
6.17
35.15
36.99
Treatments
8.70
11.50 12.50 15.68 16.89
4
4.0
2.3
19.47 20.10
7.60
8.70
15.50 14.80
K
6.90
7.90
13.63 14.53 16.20 16.87 26.17 27.37
0.00
0.00
9.70
8.8
15.00 16.33 27.07 28.13
6.90
7.90
23.33 23.33 31.20 33.20
53.24
55.50
K + Ca
6.56
7.40
12.43 13.80 14.15 15.14 24.69 25.60
0.00
0.00
4.20
5.50
13.27 14.50 24.17 25.70
6.56
7.40
16.63
48.86
51.30
19.3
27.42 29.64
L.S.D 0.05
0.3 0.3 0.1 0.4 0.2 0.5 0.2 0.4 0.0 0.0 0.1 0.1 0.2 0.2 0.5 0.3 0.3 0.3 0.2 0.4 0.2 0.5 3
7
8
7
1
4
9
7
0
0
5
5
7
5
2
8
3
3
7
2
2
7
3
0.58
0.6 9
