اثرهاي اوره و كارباريل برتنك ميوه سيب رقم گلدن دلنشين

EFFECTS OF THE UREA AND CARBARYL ON FRUIT THINNING OF APPLE ʹGOLDEN DELICIOUSʹ

An experiment was conducted in 2001 in east of Maragheh region to study the effects of time of application of carbaryl and urea on fruit thinning in ʹGolden Delicious^ apple. The factorial experiment was arranged in randomized complete block design with two replications. Experimental factors included: time of chemical application (5 and 25 after full bloom), carbaryl at 0, 300 and 600 mg 1-1 and urea at 0. 2, 4 and 6%. Some criteria such as percent of fruit thinning, fruit weight, length and diameter, fruit length/diameter ratio, total soluble solids, russeting and damage rate of shoots were analyzed. The results showed that the effect of carbaryl on percent of fruit thinning was very significant (P<0.01). The highest level of thinning obtained from 600 mg 1-1 carbaryl. The effects of urea concentration on weight, length and diameter of fruit and percentage of fruit thinning was significant (P<0.05). The highest weight and length/diameter of fruit obtained from 2% and highest fruit thinning with 6% urea. The interaction of urea concentration and time of application on shoots damage was very significant (P<0.01). The highest damage to the shoots was observed with 4 and 6 % urea that applied 5 d after full bloom. Regarding these results and considering environmental pollution with carbaryl application and harmful effect against pollinator insects, urea application at 2% in 25 d after full bloom for fruit thinning of ʹGolden Deliciousʹ apple is recommended.