The effects of plant growth regulators on red blush development on peel of mango ‘Mahachanok’

Abstract

'Mahachanok' mango is accounted as one of the most important Thai mango cultivars for export. 'Mahachanok' mango has an attractive red blush peel preferred by consumers. The development of red blush on the mango peel is related to many factors such as sunlight, temperature and some kinds of plant growth regulators (PGRs). In this study, the application of 100-2,000 mg L(‑1) jasmonic acid or 14 mg L(‑1) salicylic acid on 'Mahachanok' mango at 55-60 days after flowering and also the sunlight exposure which affected to the red blush development was investigated. The results showed that the fruit at outside of the canopy had more intense red blush compared to the fruit at inside of the canopy. The application of 300 mg L(‑1) jasmonic acid to the fruit at outside of the canopy and bagged showed the most intense red blush with the anthocyanin of 0.09-0.53 mg 100 g(‑1) FW and more red blush peel fruit than the other PGR treatments. Moreover, this treatment had no effect on fruit quality after ripening. The smell and taste were normal with soluble solids of 14.1-14.4% and titratable acidity of 0.21-0.26%. However, the control group for which the fruits were applied by water at the outside of the canopy, and had no bagging, also showed intense red blush and were sometimes better than those fruits applied with 300 mg L(‑1) jasmonic acid and bagging. This revealed that the sunlight exposure has more impact to the red blush development than with PGR application. Therefore, the most effective way to promote red blush development on the bagged mango is to use the effective PGR together with orchard management (shrub pruning) that lets the fruits expose to sunlight.