Quality and nutrient level of mango cv. 'Tommy Atkins' as affected by calcium application before harvest

The effect of calcium on quality and nutrient level of mango cv. "Tommy Atkins" was studied when applied prior to harvest on a ten-year old orchard, in Petrolina, State of Pernambuco, Brazil. Three levels of two commercial calcium sources (5.8; 11.6 and 17.3 mmol L-1 of Ca as chelate Ca and 45.0; 90.0 and 135.0 mmol L-1 of Ca as the soluble salt CaCl2H2O), and a control treatment were evaluated, in a randomized complete block design with four replications. Calcium was applied every two weeks, starting at the fruit set stage (fruits 5 to 10 mm long) up to two weeks before harvest. Six sprayings of solutions containing the calcium treatments were applied providing 12.5 L of the solution/plant in each application. The fruits were harvested in the ripening stage 2. Forty fruits were grouped in four lots of ten, placed into cardboard boxes with capacity for 6 kg and stored for 0, 20, 30 and 40 days under refrigeration (10.5 +/- 1.0 degrees C and 90 +/- 5% RH). After removed from the cold chamber, the fruits were kept for five days in a ripening room at 21 +/- 1 degrees C and 60 +/- 5% RH. N, K, Ca and Mg contents in the flesh and skin were determined in the lot equivalent to the shortest time of storage and the incidence of internal breakdown was evaluated in all four lots. Calcium application in both chelate and soluble salt forms increased the nutrient contents in the skin. Applications of chelate Ca showed to be efficient in increasing the calcium contents in the fruit flesh, contributing to prevent the occurrence of internal breakdown in short storage periods.