PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Custard apple is a climacteric fruit and starts ripening soon after detachment from the tree. It is a highly perishable fruit with a short shelf life of 1 to 2 days after ripening. The steady increase in area under custard apple has enhanced the fruit flow into the markets, which most of the time leads to a glut in the markets. There is a lack of information on the physiological studies to enhance the shelf life of the custard apple fruit after harvest. Therefore, it is necessary to investigate the effect of emulsions and chemicals to enhance the shelf life of custard apple and conserve the quality of the produce. The experiment was laid out in a Randomised Block Design with two replications. The experiments were framed with sixteen treatments. The varieties APK (Ca)1, Rayadurg, Balanagar and Mammoth were used as experimental materials with all normal cultural practices followed for aonla cultivation during 2022-2023.  The post-harvest physiological parameters such as., Specific gravity, physiological loss in weight (%), TSS (°Brix) and acidity (pH) and percentage in decay loss were recorded after treatments. Among the treatments the fruits stored at room temperature without any treatment registered higher PLW (2.04, 3.01 and 4.07%) on 2^nd, 4^th and 6^th day of storage and least physiological loss in weight was observed in wax emulsion 10% (0.39, 0.78, 1.26 and 1.60% at on 2^nd, 4^th, 6^th day and 8^th day of storage). Among the treatments, the fruits stored at room temperature without any treatment (control) registered the highest decay loss (14.86%) on the 6^th day of storage, and the least was observed in wax emulsion treatments. Among the different pretreatments on the 4^th day of storage, fruits without any treatment (control) recorded higher TSS (21.73%), but on the 6^th day, total sugar decreased to 20.72%. Wax-treated fruits did not ripen even after on 8^th days of storage. On the 6^th day of storage, fruits treated with Calcium chloride (1.5 %) recorded higher TSS (21.68%). On the 4^th day of storage, fruits without any treatment (control) recorded lower acidity (0.27%). On the 6^th day of storage, fruits without any treatment (control) recorded lower acidity (0.28%), but fruits started to decay and fruits treated with Calcium chloride (1.5 %) recorded lower acidity (0.25%). Fruits treated with Calcium chloride (1.5 %) showed a longer shelf life of 5.98 days, while a shorter shelf life of 4.65 days was noticed in the control. Fruits treated with Wax emulsion (10%) showed a longer shelf life of 9.35 days, while a shorter shelf life of 5.72 days was noticed in the control.