Incidence of Tomato Blossom-End Rot at Different Calcium Levels

摘要

Blossom-end rot (BER) is one of the most significant physiological disorders in the greenhouse tomato cultivation. It often occurs during tomato growing in the soil, but also in the soilless culture. Since the water and nutrients supply could be regulated in the hydroponics, the aim of this research was to determine the intensity of blossom-end rot occurrence at different calcium concentrations in the nutrient solution. Along with the standard nutrient solution which contained 0.85 mmol of calcium nitrate per liter, solutions with 50% reduced, and also 50 and 100% increased concentration of calcium nitrate were applied. Varying the concentration started four weeks after planting. Four tomato cultivars grown on rockwool were tested. Application of solutions with different calcium nitrate concentrations resulted with the proportion of BER affected fruits between 11.6 and 14% while the proportion of among cultivars varied from 9.3 to 21.3%. Interaction of tested factors resulted with a BER fruits proportion ranged from 7.1 to 22.5%. Between 75 and 100 marketable fruits weighing from 144 to 263 g were harvested per m~2. Marketable yield varied from 13.77 to 25.24 kg m~(-2). Application of decreased or increased calcium concentration in the nutrient solution resulted with the significant differences in BER affected fruits number between tested cultivars, which mean that the concentration should be adapted to the needs of each cultivar during the growing season. Beside the concentration of calcium and growing of cultivars resistant to the blossom-end rot incidence, special attention should be paid to the regulation and maintenance an optimum microclimate conditions in the greenhouse, in order to promote the absorption and transport of calcium through the plant.