Pre-Harvest Application Of Retain [Aminoethoxyvinylglycine (AVG)] Influences Pre-Harvest Drop And Fruit Quality Of ‘Williams’ Pears
‘Williams’ is the late ripening pear cultivar mostly produced in Eğirdir region in Turkey. ReTain [15 % aminoethoxyvinilglycine (AVG)] is a plant growth regulator used to control pre-harvest drop and increase fruit weight and firmness. The aim of this research was to determine the effects of AVG treatments on the pre-harvest drop and fruit quality of ‘Williams’ pear. Pear trees of the cultivar ‘Williams’ were sprayed 30, 21 and 7 days before commercial harvest (DBH) with AVG, at doses of 100, 125 and 150 ppm, and assessed for pre-harvest drop, yield, maturity, delay in harvest, fruit quality [fruit width (mm), fruit weight (g), fruit firmness (N), soluble solids content (SSC, %), titratable acidity (TA, %), fruit colour (L*, a*, b*, C, h°), fruit macro and micro elements content], ethylene production (µL kg-1 h-1) and respiration rate (µL kg-1 h-1) at the harvest time. Maturation of the 30 and 21 DBH AVG-treated fruits was delayed as compared to the 7 DBH AVG-treated and control groups. The pre-harvest drop decreased with all AVG applications. AVG treatments increased fruit size, weight and firmness of ‘Williams’ pear. AVG applications also decreased ethylene production and the respiration rate of fruits. As a result, 30 DBH and 21 DBH AVG-treatments at 100 ppm can be recommended for ‘Williams’ pear cultivar on both pre-harvest fruit drop, as well as in harvest date and fruit quality.