Effect of Different Concentrations of Foliar Applications of Urea, NAA and Ethrel on Fruit Thinning of ‘Dolce’ Olive cv.

Document Type : Original Article


THIS EXPERIMENT was executed in an olive private farm in ……...Cairo Alexandria desert road (64 kilometer) to study the effect of spraying with Urea at 2% and 4%, NAA at 100 mg.L-1 and 150 mg.L-1 and Ethrel at 150 mg.l-1 and 300 mg.l-1 on ‘Dolce’ olive cv. trees (7 years-old) were planted 6 x 4m and irrigated with drip irrigation. The farm received the recommended managements of Horticulture Research Institute publication (2011). As for thinning NAA with at 150 mg.l-1 concentration gave the might percentage of thinning, however the foliar application of urea 2 % concentration and Ethrel at 150 mg. l-1 gave the least ratios and the rest of the treatments showed the middle values between them. The remaining fruits per meter before harvesting were less when sprayed with NAA with at 150 mg.l-1concentration, also the highest thinning ratios was before harvesting (resulted from thinning + June dropping + dropping before harvesting) in both seasons. It is obvious that spraying NAA with at 150 mg. l-1concentration leads to the increasing significantly of the length, diameter and weight in addition to the fruit volume and yield during the two growing seasons. Although those treatments didn't gave any significant difference in the fruit moisture percentage, spraying with NAA gave the highest significant difference in oil percentage as dry weight. Depending on these results we can recommend the spraying of NAA with at 150 mg. l-1 concentration to improve the production and quality of "Dolce" olive fruits through thinning.