The effect of nitrogenous fertilization and hand thinning by brush use on
thinning and clusters quality of Perlette Seedless were studied during 2003 and 2004
seasons. The fertilizer treatments were foliar application with urea (0.5 - 3 %) at full
bloom time. soil fertilization with ammonium sulphate (20.5%). The data revealed that
vegetative growth increased after nitrogen application. Whereas, foliar application with
urea at full bloom and 50- 70 g of soil nitrogen until full bloom time were very effective
in reduction flower set percentage. Furthermore, Brush use at full bloom was the
optimal treatment for reducing flower set. In this respect, most treatments lead no
effect on nitrogen content of leaves except treatment with 70 N units until full bloom
and brush use treatment. Only vines received 70 g of soil nitrogen until full bloom time
present significant effect on length and diameter of clusters. Coefficient of cluster
compactness was significant affected by addition 30- 40 g of soil nitrogen until full
bloom time. Foliar application with urea and 50-50 g of nitrogen significant increase
berry weight, brush use gave the highest value. 0 - 3 % urea at full-bloom and 5~70 9
soil nitrogen until full bloom time or brush use significantly decreased cluster weight
and yield.
Soil fertilizer at 50 9 N per vine had a major significant effect on yield, yield
components and fruit Quality compared with the control and other treatments