The king fruit versus lateral fruit thinning effects on yield and fruit quality in apple

Abstract

This research was conducted to determine the king versus lateral fruit thinning effects on yield and fruit quality of 'Elstar', 'Granny Smith', 'Starkrimson Delicious', 'Ultra Red', 'Topred', and 'Jonagold' apple (Malus domestica Borkh.) cultivars grafted on MM106 rootstock in 2002-2003. Removal of the king fruit (KFR) treatment partially increased the yield in 'Jonagold', 'Elstar', and 'Granny Smith' cultivars while the effects were different by years in 'Starkrimson Delicious'. Leaving of the king fruit (KFL) treatment gave better results in the 'Topred' cultivar, and similar effects were obtained from both treatments in 'Ultra Red' cultivar. Non-significant differences were obtained from both treatments with respect to fruit weight in the 'Topred', 'Starkrimson Delicious', 'Jonagold' and 'Granny Smith' cultivars. Leaving of the king fruit treatment increased the fruit weight significantly in 'Elstar' and 'Ultra Red' cultivars in 2002. The values of fruit flesh firmness (lb), total soluble solids content (%), pH, titratable acidity (%), total and invert sugar quantity (g/100 g(-1)) were not found to be significantly different between the treatments with a few exceptions. The 'KFR' treatment that removed the dominant effect of the king fruit can be recommended for the 'Elstar' and 'Jonagold' cultivars because this treatment increased the yield and did not decreased the fruit weight significantly in these cultivars except for 'Elstar' in 2002. On the other hand 'KFL' treatment can be recommended for the 'Granny Smith', 'Topred' and 'Ultra Red' cultivars. Although this treatment decreased the yield of 'Granny Smith' it increased the mean fruit weight 45.6-62.7 g in the two experiment years. 'Starkrimson Delicious' did not show clear response to the treatments. (C) 2007 by The Haworth Press. All rights reserved.