Melon cultivation in various regions of the world is conditioned by water limitations. This study was developed to evaluate the potential damage to the photosynthetic structures of the F1 Caribbean Gold RZ hybrid melon cultivar grown under conditions of saline stress. The experimental carried out in a greenhouse, in the city of Recife, Pernambuco. The experimental design consisted of randomized blocks in a 2 × 4 factorial scheme with four replications. The melon plants were subjected to nutrient solutions with electrical conductivity of 2.0 or 3.5 dS m−1 applied by daily irrigation levels to maintain 55, 70, 85 and 100% soil moisture. The parameters were evaluated: dynamics of the photosynthetic surface, content of photosynthetic pigments, and chlorophyll a fluorescence, subjected to analysis of variance, using the F-test, at a probability level of 0.05. It was found that in plants exposed to 70% soil moisture, the effect of using nutrient solutions with 2.0 or 3.5 dS m−1 produced similar photosynthetic results. The proportionality adopted between the depth irrigation and nutrient apport led to characteristics of nutritional deficiency, observed as one of the causes of the reduction of photosynthetic surface and photosynthetic pigments in plants exposed to humidity levels below 70%.
Santos et al. (Sun,) studied this question.