Effects of some plant growth regulators on ‘Namdokmai Sithong’ mango fruit maturation

Abstract

© 2020 International Society for Horticultural Science. All rights reserved. ‘Namdokmai Sithong’ is one of the major mango cultivar grown in Thailand. Late season mango had higher price than on-season mango. The objective of this study was to find the effects of some plant growth regulators (PGRs) on maturation of ‘Namdokmai Sithong’ mango. The experiment was conducted in Mae Tang district, Chiang Mai province, by randomized complete block design (RCBD). The treatments included spraying young fruits with different PGRs e.g. 1) 50 mg L-1 GA3, 2) 100 mg L-1 BA, 3) 100 mg L-1 NAA, 4) 50 mg L-1 GA3 with 100 mg L-1 BA, 5) 50 mg L-1 GA3 with 100 mg L-1 NAA, 6) 100 mg L-1 BA with 100 mg L-1 NAA, and 7) spraying distilled water as the control. Application of these PGRs to retard fruit maturation and ripening did not succeed. On the other hand, spraying 100 mg L-1 NAA at 50 days after full bloom (DAF) and re-applying every two weeks for four times accelerated fruit maturation and ripening for 5 and 7 days, respectively, comparing to the control, without any effects on fruit size at maturity. However, there were slightly negative effects as by decreasing the total sugar content and uronic acid (component of pectin) content in ripe mesocarp. This result can be adapted to be used for early-season mango production before most of mangoes will be on the market.