. Jawal, M. Anwarudin Syah, E. Mansyah, Martias, T. Purnama, D. Fatria, and F. Usman. 2010. The Effect of Drip Irrigation and Fertilization to Control the Yellow Latex Incidence on Mangosteen Fruit. The yellow latex is a major problem on mangosteen fruit quality, especially for export. The yellow latex occured in the fruit flesh caused improper taste. The experiment was conducted in the mangosteen production center, Pesisir Selatan, West Sumatera. The experiment was designed as super imposed trial. The data was analized using factorial randomized block design with two factors and three replications. The first factor was irrigation (no irrigation and with irrigation) and the second factor was fertilizer (no fertilizer, NPK, NPKCa, and NPKCaMg). Drip irrigation was applied continously on the generative phase. The objective of this experiment was to find out the control technique of the yellow latex on mangosteen fruit. The parameter observed were the percentage of yellow latex on outer and inner skin fruit of mangosteen. The results of the experiments indicated that drip irrigation during the generative phase was able to decrease the yellow latex incidence on the inner fruit skin of mangosteen up to 36%, but the decreased of yellow latex incidence on the outer fruit skin of mangosteen was not consistent. Fertilization did not significantly reduce yellow latex incidence on mangosteen fruit.