Estratégias de manejo de irrigação e aplicação foliar de prolina no cultivo de Annona squamosa.

Abstract

Irrigation is crucial for fruit growing in the semiarid region of the Northeast, where water scarcity represents the greatest challenge. To mitigate the effects of water deficit, it is essential to adopt effective practices, which start with irrigation management, such as determining a watering schedule or applying elicitors, such as proline. In this context, the objective was to evaluate the effects of foliar application of proline on the physiological aspects, nutrition, production and post-harvest quality of sugarcane fruits grown under irrigation schedules, in two production cycles in the semiarid region of Paraíba. The research was developed at the ‘Rolando Enrique Rivas’ Experimental Farm of the Center for Agrofood Science and Technology of the Federal University of Campina Grande, located in the municipality of São Domingos, Paraíba. A randomized block design was adopted, in a split-plot scheme, with the plot having four irrigation shifts (1, 4, 8 and 12 days) and the subplots having two proline concentrations (0 and 10 mM), with four replicates and four useful plants per plot. Irrigation with a 12-day irrigation shift resulted in changes in the physiology in the second year of cultivation of the custard apple, negatively affecting the synthesis of photosynthetic pigments and maximum fluorescence. The production components and the quality of the custard apple fruits in the two years of cultivation were benefited by the increase in the interval between irrigation shifts. The foliar nutrient contents were altered with a 12-day irrigation shift; however, with the exception of nitrogen contents, the custard apple plants are at nutritional sufficiency levels. Despite contributing to the reduction of electrolyte extravasation in the leaf blade, foliar application of proline did not present benefits in the physiology and production components of pine trees. Irrigation shifts of up to 12 days proved efficient in optimizing water use in pine tree cultivation in the semiarid region of Paraíba.