Increased productivity of Thai fruits by using plant growth regulators
Plant growth regulators (PGRs) play an important role in the increase of fruit production efficiency and availability all year round. As seen in 2016, Thailand imported PGRs 2.7 million t or 84.3 thousand USD. From the Hazardous Substance Act issued in 1992, PGRs are accounted for agricultural hazardous substance, same as pesticide and plant disease control substance. However, before launching any PGRs in markets, those PGRs have to be registered by the Department of Agriculture. Currently, the registered PGRs are suggested to be widely used with fruits, vegetables, ornamentals, field crops, rice, and rubber. Most registered PGRs are used for fruits, especially paclobutrazol. It is used to induce flowering in mango. Next is ethephon inducing flowering in pineapple. Moreover, there are some researches done by the Horticultural Research Institute during 2011-2015 on applying PGRs in fruit. One of those is the study of using PGRs to control flowering in rambutan. This study found that applying 1,000 ppm paclobutrazol or 15,000 ppm mepiquat chloride or 5,000 ppm ethephon on the main branches of rambutan 2 months before flowering could hasten flowering 5-6 days. Another study is using jasmonic acid to increase red blush on 'Mahachanok' mango peel. This study showed applying 300 ppm jasmonic acid on mango fruit at 55-60 days after blooming helped develop red blush on the fruit peel by increasing of anthocyanin content. Therefore, PGRs help distribute the fruit production and improve the quality to meet the market requirements in both quality and time. However, PGRs have to be used on the right kind, rate, time, and way to get the highest efficiency.
Makkumrai, W., Sangudom, T., Chatbanyong, R., Tongtao, S. and Daoreung, C. (2018). Increased productivity of Thai fruits by using plant growth regulators. Acta Hortic. 1206, 175-182
ethephon, flowering, paclobutrazol, production