Document Type : Original Article
Authors
Horticulture Research Institute, A.R.C., Egypt.
Abstract
This investigation was carried out during 2005/2006 and 2006/2007 growing seasons to study the effect of holding irrigation periods and foliar application with urea on vegetative growth, leaf chlorophyll content, leaf carbohydrate fractions and fruit quality of lime trees. The treatments were; holding irrigation for 15,30,45 and 60 days with three urea spraying treatments; once, twice and without spray. The obtained results indicated that, holding irrigation for 30 days with spraying once or twice, in both seasons, gave the best intereaction for increasing shoot length and leaf area. As for leaf chlorophyll and carbohydrate concentrations, the results revealed that, holding irrigation for either 30 or 45 days with urea spraying twice, in both seasons, markedly increased leaf chlorophyll catogeries (A&B) and carbohydrate fractions concentrations and gave the best interactions. Moreover, holding irrigation for 15 days without foliar urea, in both seasons, gave the highest interaction for leaf starch and total carbohydrates when compared with holding irrigation period for 60 days with urea spraying twice. For physical fruit properties; including fruit length and diameter; the results proved that, in the first season, holding irrigation for either 15 or 45 days with urea application; once, twice or without foliar urea (as a control) markedly increased fruit length and diameter and gave the best interactions. However, in the second season, the differences were not significant in this respect. Fruit juice volume, in both seasons, significantly increased when irrigation was held for 15 days. Besides, no effect of foliar urea spraying treatments in this respect; especially, in the first season. Moreover, the best interactions for lime juice volume were obtained between holding irrigation for 15 days with urea spraying once. For chemical fruit properties, including total soluble solids, fruit juice acidity and vitamin C percentages; by holding irrigation for either 30 or 45 days and urea application twice, in both seasons, caused significant increase in their fruit juice content of these tested variables and gave the best interactions. On the contrary, holding irrigation for 60 days with or without foliar urea sprays had a negative effect on all the above mentioned parameters and reduced fruit quality.
Main Subjects
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