THAKUR, K.S.GHANSHYAM2016-05-312016-05-312013http://krishikosh.egranth.ac.in/handle/1/66491ABSTRACT The present investigations entitled “Postharvest handling and storage of nectarine (Prunus persica var. nucipersica Schneid.)” were conducted during 2011 and 2012. The whole programme of work was divided into four experiments. In Experiment-I an attempt was made to determine the optimum maturity for harvesting of nectarine cultivars May Fire, Snow Queen, Silver King and Red Gold on the basis of physicochemical characteristics of the ripened fruit after a ripening period of 7 days under ambient conditions. In Experiment-II and Experiment-III effects of various pre- and post-harvest treatments on changes in physicochemical characteristics of fruits of the cv. Snow Queen, have been observed during storage. While, in Experiment-IV the best concentration of each substances tried as pre- and post-harvest treatments were applied in concentration to develop a complete protocol. Fruits for experiments pertaining to standardization of maturity in relation to quality and storage and for other experiments were procured from HRS, Kandaghat. For assessing maturity, fruits of each variety were harvested at three day intervals commencing from 6 days before the expected harvest date, with the last sampling date being 6 days after the expected harvest date. On the basis of physico-chemical and sensory characteristics the optimum time for harvesting of May Fire, Snow Queen, Silver King and Red Gold was found to be 68± 3, 83± 3, 83± 3 and 89± 3 days, from the date of full bloom, respectivelly. A significant increase in fruit size, weight, volume, pulp: stone ratio, TSS, sugar and carotenoid content was observed with advancement of harvesting period, while, a decrease in firmness, titratable acidity and ascorbic acid content. After a ripening period of 7 days fruits harvested on 3rd harvesting date retained better physico-chemical and sensory attributes in comparison to fruits harvested on other dates. All the preharvest treatments showed a beneficial effect on physical, biochemical and sensory parameter of fruits in comparison to control. Among the preharvest treatments, calcium chloride @ 1.5 per cent, Neemazal @0.45 per cent, salicylic acid @3000 ppm and CPPU @15 ppm proved to be most effective in maintaining fruit quality and minimizing deterioration during 28 days storage at 3 ±1 ºC. CPPU @15 ppm, was the most effective treatment in increasing fruit size, weight and total soluble solids (TSS), reducing and total sugars, ascorbic acid and total phenol content in fruits. However, CaCl2 treatment @ 1.5 per cent proved to be the most effective in reducing physiological loss in weight and minimizing deterioration in fruit quality and in retaining maximum firmness, acidity, pectin, total phenols and overall acceptability of fruits during 28th day storage period. These treatments were also effective in reducing the respiration rate and enzymatic activities, thereby reducing the overall ripening process and prolonging storage life. Among postharvest treatments, fruits that were treated with 750 ppb 1-Methylcyclopropene (1- MCP) retained maximum TSS, sugars, titratable acidity, pectin, ascorbic acid and exhibited reduced respiration rate and enzymatic activities, thereby proving to be effective in increasing storage life and overall acceptability of fruits. Other treatments such as Starlight wax coating @50 per cent, 5 minute dip in 0.15% Neemazal @ 55°C, hot water dip @ 55°C for 5 minute and dipping in mint leaf extract @ 30% were also quite effective in retaining storage quality. Combination of pre and postharvest treatments were generally more effective than the individual treatments. Out of all the combinations tried CaCl2 (1.5%) + 1-MCP (750 ppb) fumigation was found to be most effective in maintaining quality during storage.enfruits, storage, acidity, harvesting, biological development, developmental stages, precipitation, peaches, application methods, organic acidsNECTARINE (Prunus persica var. nucipersica Schneid.)Thesis