Singh, V. P.Dangwal, Vivek2022-10-152022-10-152022-08https://krishikosh.egranth.ac.in/handle/1/5810188957The present investigation was carried out in the mrig bahar of year 2021 at Horticulture Research Centre, Patharchatta as well as in Postharvest Laboratory of Department of Horticulture, College of Agriculture, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar. The experiment was laid out in randomized block design and complete randomised design with three replications comprising of 13 treatments (Potassium nitrate and potassium sulphate @ 1.0, 2.0 and 3.0% each, calcium nitrate and calcium sulphate @ 0.5, 1.0 and 1.5% each and control). The results showed that the maximum leaf and fruit nutrient (N, P and K) content, leaf length, breadth, area and total chlorophyll were recorded in T3 (potassium nitrate @ 3.0 %). Maximum fruit yield per plant, fruit yield per hectare, fruit retention and fruit weight as well as least amount of fruit drop and fruit cracking were recorded in T2 (potassium nitrate @ 2.0%). The fruits were stored in ambient condition after harvesting for further observations. The result revealed that pre-harvest sprays of potassium and calcium compounds were effective in increasing fruit yield, quality and shelf life of winter season guava fruit. T9 (calcium nitrate @ 1.5%) treatment recorded the highest fruit length, breadth, inner diameter, thickness of the flesh, seed weight, pectin content and shelf life. T2 treatment (potassium nitrate @ 2.0%) recorded maximum fruit weight, fruit volume, specific gravity and biochemical parameters i.e. total soluble solids, total sugars, reducing sugar, non-reducing sugar and ascorbic acid. Over all, it can be concluded that pre-harvest foliar spray of potassium nitrate @ 2.0 per cent i.e. first spray at fruit set and second spray at one month after first spray, is beneficial for increasing fruit yield, quality, shelf life and reducing fruit cracking of winter season guava cv. ‘VNR Bihi’ under Tarai conditions of Uttarakhand.EnglishThesis