Effect of Mepiquat Chloride, Chlormequat Chloride, and Paclobutrazol on Flowering of Mango cv. Nam Dok Mai Si Thong

Abstract

The study on effect of mepiquat chloride, chlormequat chloride, and paclobutrazol on flowering of mango cv. ‘Nam Dok Mai Si Thong’ was carried out during July 2012 to March 2013 at Sansai district, Chiang Mai. The experiment was designed based on Randomized Complete Block Design (RCBD) with 5 treatments and 3 blocks (10 trees each); 1) control, 2) soil drench with paclobutrazol 1 g a.i/m², 3) foliar spray with mepiquat chloride 3,000 mg/l, 4) foliar spray with chlormequat chloride 1,000 mg/l, and 5) foliar spray with mepiquat chloride 3,000 mg/l plus chlormequat chloride 1,000 mg/l. The results showed that all growth retardant substances could induce flowering of mango trees faster than control, which flowered at 87-92 days after treatments. The treatment of soil drench with paclobutrazol 1 g a.i/m² gave the highest flowering about 96.16% whereas foliar spraying with mepiquat chloride 3,000 mg/l and chlormequat chloride 1,000 mg/l and mepiquat chloride 3,000 mg/l plus chlormequat chloride 1,000 mg/l showed lower flowering than paclobutrazol at 65.46-82.13%. All treated treatments gave similary flower quality, 67.11-77.54% of full flower, 22.46-32.89% of leafy flower. Moreover, paclobutrazol 1 g a.i/m², mepiquat chloride 3,000 mg/l plus chlormequat chloride 1,000 mg/l and chlormequat chloride 1,000 mg/l had more effect on flower number per panicle than mepiquat chloride 3,000 mg/l. However, all foliar spraying treatments promoted higher percentage of fruit setting than using paclobutrazol.