Document Details
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Document Type |
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Thesis |
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Document Title |
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Effect of some growth regulators spray on fruit quality of Barhee dates at harvest and after cold storge تأثير الرش ببعض منظمات النمو على خواص جودة ثمار التمر صنف البرحي عند الحصاد وبعد التخزين البارد |
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Subject |
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Department of Arid Land Agriculture |
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Document Language |
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Arabic |
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Abstract |
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Barhee’ is a mid season cultivar being extensively cultivated in the KSA and the Gulf region. There is a growing demand in international market, for excellent quality dates of cultivars such as ‘Barhee’. ‘Barhee’ dates are different than other cultivars in which fruit are marketed and consumed fresh at the mature full yellow (bisir) stage as a crispy apple-like fruit due to low contents of soluble tannins. However, at the rutab stage (ripening), fruit become softer and sweeter but their market value decreases. Under the KSA conditions, ‘Barhee’ dates reach the bisir stage during extremely hot dry summer (early to mid July). After harvest, fruit ripen rapidly especially at ambient conditions and thus lose much of their marketing value. Generally, there is little literature information on storage of ‘Barhee’ dates as well as on other cultivars that are especially consumed at the bisir stage. Therefore, searching for additional pre- and postharvest treatments to enhance the cold storage efficiency in prolonging the storage life of bisir ‘Barhee’ dates is critically required. It is well known that growth regulators (GR) have important role in fruit maturation and ripening. In this study, uniform ‘Barhee’ date palms were sprayed (only the bunches) with some growth regulators gibberellic acid (GA3), naphthalene acetic acid (NAA), benzyladenine (BA) and salicylic acid (SA) (at 50 or 100 ppm) at two stages of development namely the hababouk (4-5 weeks from pollination) and the kimri stage (9-10 weeks from pollination) as an attempt to prolong the cold storage life of bisir ‘Barhee’ dates. This experiment was conducted at the Agriculture Research Station of the College of Meteorology, Environment and Arid land Agriculture in Hada Al-Sham valley, KSA and the laboratories of the college. Each treatment was repeated three times in a completely randomized design. Fruit maturation was followed (color change from light green to yellow was recorded). At the bisir stage, fruit samples were picked for quality measurements (fruit, flesh and seed weight, diameter, length, sugars, total phenols, soluble tannins, acidity and vitamin C concentrations) both at harvest and also during 45 days of cold storage period at 1oC. The results sowed that the percentage of bisir (mature) fruit gradually increased close to the harvest time. All the applied growth regulators slightly delayed fruit maturation (the transition from kimri to bisir stage according to yellow color development) compared to the control. In this respect, SA at 100 ppm and GA3 at 50 ppm were the most effective treatments. NAA and GA3 at both concentrations and SA at the low concentration had no effect on bunch weight despite it increased fruit weight, length and diameter, in contrast to BA at both concentrations and SA at high concentration. This is possibly due to the effect of these GR on fruit number/bunch. At harvest, most of the physical quality characteristics of fruit were improved by GR spray compared to control. SA at 50 ppm and GA3 and NAA at 50 and 100 ppm significantly increased fruit weight, length and diameter compared to control. All the GR treatments except for SA at 50 ppm significantly increased the flesh/seed ratio compared to control. TSS concentration significantly increased by GA3 at 100 ppm, NAA and SA at both concentrations compared to control and other GR treatments. Also fruit acidity was significantly higher at NAA and the low concentration of GA3 and BA compared to control and other GR treatments. However, SA at 100 ppm decreased fruit acidity compared to control but this treatment resulted in a significant increase in vitamin C concentration compared to all other treatments. In this respect, both total phenols and soluble tannins concentrations were not significantly affected by the applied GR. During 45 days of storage at 1oC, NAA at 50 ppm gave the lowest rutab percentage compared with all the other treatments, except for GA3 at 100 ppm which was similar to control. On the other hand, SA at 100 ppm followed by GA3 at 50 ppm produced the highest rutab percentage that was significantly higher than control. The rutab percentage gradually increased during cold storage to reach 12.3, 53.0 and 60.4% after 15, 30 and 45 days, respectively. Non of the applied GR affected the weight loss of fruit during cold storage. However, the weight loss of fruit significantly increased during to storage reaching 1.73% after 45 days. TSS concentration significantly decreased in bisir fruit during cold storage. NAA and GA3 at 50 ppm, and SA and BA at 100 ppm significantly decreased TSS concentration compared to control. Fruit acidity decreased during storage. Most of the applied GR decreased fruit acidity compared to control, except for both GA3 and SA at 50 ppm. It is interesting that all the GR treatments especially SA significantly increased the concentration of vitamin C during cold storage compared to control. The concentration of vitamin C gradually decreased as the storage period prolonged. The concentration of total phenols and soluble tannins gradually decreased during storage and were slightly affected by GR treatments. In conclusion, the results showed that pre-harvest spray of growth regulators at earlier developmental stage (the hababouk and the late kimri stage) especially with NAA at 50 ppm or GA3 at 100 ppm improved fruit quality at harvest and delayed rutab development during cold storage compared to control. In this respect, SA at 50 ppm significantly increased fruit weight, length and diameter at harvest compared to other treatments. However, the GR treatments showed slight effects on fruit quality characteristics and ripening during the subsequent cold storage at 1oC. Therefore, additional treatments together with GR such as packaging or storage at modified atmosphere conditions were suggested for future research. |
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Supervisor |
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Prof. Adel.D.Alqurashi |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1434 AH
2013 AD |
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Co-Supervisor |
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Dr. Refaat.A.Abohassan |
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Added Date |
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Saturday, June 15, 2013 |
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Researchers
| عبد الله بركان المطيري | al mutairy, Abdullah burkkan | Researcher | Master | |
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