Effect of combined application of fungicides and hot water quarantine treatment on postharvest diseases and quality of mango fruit

摘要

Postharvest diseases and disorders reduce mango fruit quality and cause severe losses, sometime yielding completely unmarketable fruit. Further, the risk of fruit fly presence has made it mandatory to use hot water quarantine treatment (HWQT) as a pre-requisite for market access to countries like China and Iran. In this study, different fungicides and hot water quarantine treatments combinations were evaluated for their effects on mango fruit cv. Samar Bahisht Chaunsa, which were stored for 21 days at (13±1°C, 85±5%RH). Application of Topsin-M @ 1 g L-1 as field dip for 1 min (pre-transport) followed by HWQT @ 48°C for 60 min., significantly suppressed postharvest diseases. HWQT generally led to increased internal discoloration as compared to control, and hot water injury was higher in fruit subjected to Iran protocol (45°C for 75 min) compared to China protocol (48°C for 60 min). NaOCl alone or with HWQT, caused higher internal discoloration of fruit. All physical treatments induced some degree of soft nose but combination of NaOCl with HWQT was found to accelerate the problem compared to control. Fruits subjected to NaOCl @ 2.5 g 10L-1 and Topsin-M @ 1 g L-1 both followed by + HWQT @ 48°C for 60 min showed higher levels of total titratable acidity. However, non-significant effects of the treatments were observed on fruit colour, total soluble solids, total and non-reducing sugar contents and organoleptic acceptability of the fruits. Overall, postharvest, pre-transport application of Topsin-M @ 1 g L-1followed by HWQT (48°C for 60 min) helped reduce incidence of postharvest diseases, besides fulfilling market access criteria. The higher degree of soft nose development in HWQT fruits; and generally poor post-storage peel colour development warrant further studies.