Khachathan Phonrong and Sayan Sdoodee

pp. 701 - 712

Abstract

To assess crop load effect on yield and quality of mangosteen fruits, an experiment was established in a farmer’s orchard at Tambol Koh Hong, Hat Yai, Songkhla. The experiment was arranged as a completely randomized design with 4 treatments: 1) <500 fruit pt^-1 2) 501-1000 fruit pt^-1 3) 1001-1500 fruit pt^-1 and 4) >1500 fruit pt^-1 with 6 replicates. Twenty-four 14-year mangosteen trees were used. It was found that the mangosteen trees in the treatment of 1001-1500 fruit pt^-1 provided a significantly high yield (84.23 kg pt^-1) with a high percentage (66%) of standard fruit size (>70 g.), while the mangosteen trees in the treatment of <500 fruit pt^-1 gave the lowest yield. Although the significantly highest yield (119.89 kg pt^-1) was found in the treatment of >1500 fruit pt^-1, most of the fruits were of small size. It was remarkable that the mangosteen trees in the treatment of >1500 fruit pt^-1 exhibited high physiological response with high stomatal conductance and water uptake. After harvesting, leaf flushing and root growth of the plants in the treatment of >1500 fruit pt^-1 were poor. This would lead to an occurrence of alternate-bearing in the consecutive year.