Physiological and productive performance of papaya plants irrigated in a semiarid environment

Resumo

Papaya tree has great economic importance and potential of cultivation in semiarid environment. However, water scarcity in this region may inhibits photosynthetic activity and limit the production of this crop, being necessary to use strategies of irrigation management that rationalize water and allow the production of the plants without affecting photosynthetic activity. In this sense, this study aimed to evaluate the physiological and productive performance of papaya “Calimosa” under different water replacement rates in semiarid environment. Papaya plants were irrigated with four water replacement rates (50, 75, 100 and 125% ETo) from 30 days after transplant of seedlings to the experimental area.  At 10 months after transplant were realized evaluations of gas exchange and chlorophyll fluorescence, and at 12 months after transplant, it was started harvesting fruits to determine the yield. Water replacement rates significantly influenced the parameters of gas exchange of papaya with better results on rates of 125% ETo. However, application of water replacement rates of 100% ETo provide conditions adequate for the activity of gas exchange and better quantum efficiency of photosystem II, that contribute to fruit production in papaya. With rates less than 75% ETo occur drastic reductions in gas exchange, quantum efficiency of photosystem II, and fruit production of papaya, which impairs its cultivation in semiarid environments.