Effects of Plant Growth Regulators on Flowering of Mango cv. Dang-Jakkrapad in Chiang Mai Province

The study of effects of plant growth regulators on flowering of Mango cv. Dang-Jakkrapad in Chiang Mai Province aimed to induce off-season flowering of mango cv. Dang-Jakkrapad. The experiment employed Randomized Complete Block Design (RCBD) by assigning 18 plants as 1 block, with 3 blocks in total, and comparing 9 methods. The results showed that soil drenched with paclobutrazol at the rate of 1 g a.i./m2, foliar spraying with mepiquat chloride and with chlormequat chloride resulted in earlier flowering than the control group. Flowering emerged during 71 - 76 days after the application. Pouring the soil with paclobutrazol at the rate of 1 gram of the active ingredient per square meter of the area under the canopy resulted in flowering as high as 88.83 percent, the inflorescence was as high as 87.39 percent, and the average number of flowers per inflorescence was 1,526.66 flowers. Therefore, the use of pacobutrazol is appropriate for inducing flowering of the mango cv. Dang-Jakkrapad as it affects the percentage of flowering. The total number of inflorescences and the number of flowers per bouquet are higher than other treatments. This study provides guidelines for managing mango cv. Dang-Jakkrapad for effective off-season flowering and increasing grower income in Chiang Mai. This study can therefore be used as a guideline for effectively managing the Mango cv. Dang-Jakkrapad to achieve off-season flowering, thereby helping to increase the income of farmers growing this variety of mango in Chiang Mai province.