Influence of bagging on fruit quality and mineral composition of Himsagar mango grown in new alluvial zones of West Bengal

Abstract

The effect of polybagging of mango (Mangifera indica L.) fruits was evaluated at different stages of fruit development (35, 45, 55 and 65 days after fruit set). Fruits were harvested at different stages of maturity (75, 85 and 90 days after fruit set) and allowed to ripen at room temperature (34-36°C, RH 85-90%). The use of bagging at different stages of fruit development improved the appearance of fruit, fruit weight and size through other effects such as increased relative humidity and a consequently reduced fruit water loss. The maturity of fruits, at all stages of fruit harvest, was delayed with increasing bagging duration. Early bagging of fruit (35 days after fruit set) delayed the development of ripening characteristics in comparison to delayed bagging and unbagged control fruit, which ripened earliest. This was clearly evident from the carotene content in the mango flesh, at the different stages of harvest and of ripening fruit, which was the result of  higher temperature inside the bags. In bagged fruits usually day/night temperature fluctuations were reduced and there was a cut off in the temperature curve inside the bag. The total soluble solids and sugar content were higher and titratable acid content was always less in unbagged fruit at all stages of fruit harvest and fruit ripening. Mineral elements were also affected by the number of days of bagging. The reduced Ca concentration in long-duration bagging (early bagging) might be due to increased RH around the fruits. Fruits bagged for 55 days recorded an  increased content of N, P, Zn, Mn and Fe while fruit calcium concentration was reduced by bagging for 55 days. Anthracnose and stem-end-rot (SER) caused by Colletotrichum and Diplodia spp. Respectively were reduced by bagging in both years through a reduction in contact between disease propagules and fruits. These results indicate that bagging can improve fruit quality by reducing disease, lead to a better appearance of fruit and increase fruit weight and size.