Effects of Aminoethoxyvinylglycine and High Temperatures on Fruit Set and Fruit Characteristics of Heat-cultured Satsuma Mandarin

Abstract

The effects of temperature and aminoethoxyvinylglycine (AVG), an ethylene synthesis inhibitor, on fruit set and growth of satsuma mandarins (Citrus unshiu Marc.), using 6- and 14- year-old potted trees in a temperature-controlled growth chamber and in a greenhouse, respectively, were studied. Trees, kept at 30°C in the daytime from bloom to the physiological fruit drop, resulted in severe fruit abscission more than did those kept at 25°C. Application of 200 ppm AVG at the start of blooming reduced ethylene production from flower and young fruit, and improved fruit set at 30°C. Fruit size, rind color, and juice characteristics indicated that high temperature and treatment with AVG advanced fruit growth and maturity, compared to temperatures presently used commercially. Therefore, the combination of AVG, which promotes fruit set, and heating to 30°C are useful management tools to accelerate fruit growth and quality.