ملخص البحث
Three years old Anna apple trees budded on MM106 and Malus rootstocks were sprayed with Hydrogen Cyanamide (Dormex) in winter at (1.0, 2.0 and 3.0 %), while 0.0% served as control. The effect of
Dormex on bud break, fruit set, fruit quality and vegetative growth were studied. Dormex markedly advanced buds break and increased the final fruit set at different concentrations for spurs and buds on one year old
shoots, also increased significantly average fruit weight, fruit size, fruit length, fruit diameter, TSS % and TSS/acid ratio in compare to the control. However, Dormex especially at 2 and 3 % decreased significantly both
firmness and fruit acidity. The percentage of bud break of spurs buds, final fruit set; average fruit weight, fruit size, fruit length, fruit diameter, total soluble solids and TSS/acid ratio were significantly higher on MM106 than
on Malus rootstock in both seasons. However, L/D ratio, acidity and firmness of fruits were higher on Malus than on MM106 rootstock. In general, trees grown on MM106 and treated with Dormex gave the highest values
of final fruit set, average fruit weight, fruit size, fruit length and fruit diameter in compare to the other treatments. Dormex improved all vegetative growth parameters of trees grown on both rootstocks in compare to the control. All vegetative growth parameters were higher on Malus than those on MM106.