EFFECT OF PACLOBUTRAZOL APPLICATION COMBINED WITH POTASSIUM NITRATE AND BICOMINE SPRAY ON FLOWERING AND FRUITING OF MANGOSTEEN (GARCINIA MANGOSTANA L.)

A study was conducted to determine the effect of paclobutrazol application combined with potassium nitrate or bicomine on flowering and fruiting of mangosteen. Paclobutrazol was applied either by soil application at 2g a.i. per tree or foliar spray at 1000 mg L^-1 than followed by foliar spray of potassium nitrate or bicomine on preset timing prior to paclobutrazol application. The results showed that application of paclobutrazol combined with potassium nitrate or bicomine enhanced flowering and fruiting of mangosteen. However, only foliar spray of paclobutrazol followed by applications of KNO₃ or bicomine at one month after PBZ spraying and then repeated applications of this chemical during flowering and fruit development showed significant results. The proportions of fruits of different sizes at harvested (i.e. percentage of small, medium or large fruits) demonstrated certain differences among the treatments. However, fruit quality except fruit size during harvesting was not affected regardless of the treatments imposed to the trees.