Pengendalian Getah Kuning Pada Buah Manggis Dengan Irigasi Tetes dan Antitranspiran Chitosan (Control of Yellow Latex on Mangosteen Fruit by Using Drip Irrigation and Chitosan Antitranspirant)

ABSTRACT. Mangosteen is the largest exported fresh fruit from Indonesia, but only about 12.79% of the total production can be exported due to low quality. Yellow latex or gamboge disorder is the main cause of low quality mangosteen fruit. This study aimed to control the yellow latex of the mangosteen fruit by using drip irrigation and Chitosan antitranspirant. The study was conducted at farmer’s mangosteen garden in Munduk Bestala Village, Seririt Subdistrict, Buleleng Regency, during dry season (April–November 2011). The research was arranged as split plot design which consisted of two factors in a randomized block design. The main treatments were two levels of drip irrigation such as drip irrigation (It) and control (Ik), while the subplot treatments were three levels concentration of Chitosan antitranspirant such as 0 % (A0), 0.15% (A1), and 0.30% (A2). The experiment was replicated nine times. The result of experiment indicated that interaction between drip irrigation and Chitosan antitranspirant has no significant different on yellow latex of mangosteen fruit. In contrast, drip irrigation decreased significantly yellow latex both at outer fruit skin and aril. The aril without yellow latex on drip irrigation treatment was 83.70%, whereas in control only 36.30%. Chitosan antitranspirant also increases the percentage of outer fruit skin and fruit aril without yellow latex. Fruit aril without yellow latex at concentration of 0.15% and 0.30% was 60.00% and 64.44%, respectively, while at control was only 55.56%. In addition, Chitosan antitranspirant was not decrease photosynthesis process which was reflected by not reducing of sugar content, total sugar, and sucrose of leaves. Keywords: Garcinia mangostana L.; Yellow latex; Photosynthesis; Antitranspirant; Drip irrigation