522 Study on the Effect of GA4+7, GA3, and Dimethoate on Russeting of `Golden Delicious' Apple

Abstract

Skin russet in apple fruit, which causes a considerable decrease in marketing and exporting potentials, is one of the major problems in the word fruit markets. In this project, the effect of GA4+7, GA3, and dimethoate on russeting of `Golden Delicious' apple was examined. A complete randomized-block design with 13 treatments and four replications was used. In all treatments, the trees had the same size and medium growth and were homogeneous. The distances between trees were 6 x 6 m and the age was 18 years. The total number of trees, including controls, was 52. The 12 treatments were GA4+7 and GA3 with 10 ppm and 20 ppm concentrations in one and two times of spray in petal fall (PF) and PF + 10 days. Dimethoate at a concentration of 0.03% and 0.05% in one and two times of spray in PF and PF + 10 days. Fruit russeting was reduced in all treatments except with GA3. The largest decrease of russeting was caused by GA4+7, especially with 20 ppm and also dimethoate with a significant decrease in russeting. Seed number also decreased significantly with GA4+7 and GA3, but dimethoate had no significant effect on TSS, while ACD ratio was decreased significantly by GA4+7 and dimethoate, but GA3 had no significant effect. Compared with the control, the treatment did not show differences with the other characteristics.