Pre-harvest Application of Calcium Maintained Fruit Quality in Cold Stored Plum

An experiment was conducted to study the influence of pre-harvest applications of different concentrations of calcium nitrate on various physico-chemical parameters of plum (Prunus salicina L.) cv. Satluj Purple under cold storage conditions. Uniform and healthy plants of plum cv. Satluj Purple were sprayed with calcium nitrate (1.0,1.5 and 2.0%)in 2^nd and 3^rd week of April and control plants were water sprayed only. Fruits from both treated and control plants were harvested at colour break stage, and then stored at low temperature conditions (0–1°C and 90–95% RH) for 35 days. Evaluation of different physico-chemical parameters were made on 0 day and after 7, 14, 21, 28 and 35 days of storage. The results revealed that two sprays of Ca(NO₃)₂ @ 2.0% retained maximum pulp: stone (15.37), total soluble solids (12.93%), titratable acidity (0.69%), reducing (6.52%) & non-reducing sugars (2.64%) and total phenolics content (101.19 mg 100g⁻¹) at the end ofstorage. The fruits treated with two sprays of Ca (NO₃)₂ @ 2.0% were effective in maintaining the quality of fruits without any spoilage up to 35 days under low temperature storage conditions.