Physiological behavior of melon cultivars submitted to soil salinity1

ABSTRACT Melon is one of the most important vegetables for the Brazilian foreign trade. However, in semi-arid areas, the irregular rainfall, excessive use of fertilizers and, especially, poor quality water contribute to the soil salinization, becoming a limiting factor and damaging the photosynthetic apparatus, as well as affecting yield. This study aimed to evaluate the physiological behavior of melon cultivars submitted to soil salinity. For that, an experiment was conducted in a greenhouse, using a randomized block experimental design, in a 3 x 5 factorial scheme, with the first factor related to melon cultivars (Iracema, Goldex and Natal) and the second one related to soil salinity levels (0.3 dS m-1, 1.3 dS m-1, 2.3 dS m-1, 3.3 dS m-1 and 4.3 dS m-1 of electrical conductivity), with four replications. For soil salinization, a saturation extract with initial soil salinity of 0.3 dS m-1 was obtained, while the other levels were prepared by adding NaCl to the soil. The physiology of melon plants is negatively affected by the increased salinity in the soil. The evaluated cultivars do not show differences in tolerance for the physiological response to soil saline stress.