Effect of pruning, defoliation and nitrogen fertilization on growth, fruit set and quality of Abdel-Razik annona cultivar.

Includes reference.

This investigation was carried out during two successive seasons of 2003 and 2004 on AbdelRazik cultivar Annona. The trees were II years old grown in a private orchard at Badr Center, Behera Governorate. The study aimed to show the effect of some pruning levels, defoliation and nitrogen fertilization on growth, fruit set and quality. Results revealed that, N fertilization combined with pruning regimes gave the greatest values. Such treatments led to increase the lateral shoots number and number of leaves per shoot. The effective treatment was heading back by removing 20 cm. from shoot top plus N fertilization. All pruning treatments including defoliation either with or without N fertilization advanced flowering date while flowering period was not affected. The investigation showed that pruning regimes and pruning combined with N fertilization treatment increased number of flower per shoot, fruit set percentage and yield. The effective treatment, in this respect, was heading back by removing 10 cm. of shoot top + N fertilization. Such treatment had the highest value of fruit weight. No significant differences between different treatments and control concerning the fruit height, diameter and WD, ratios were found. Treatments with N fertilization decreased the presence of TSS while total acidity was increased; this led to decrease in TSS/acid ratio. N fertilization increased leaf content of N and P while leaf content of K was not affected. Results revealed that, N fertilization supported with pruning improved growth, fruit set and fruit quality.

Summary in Arabic.

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