Lâminas de irrigação e polímero hidroabsorvente no crescimento, fisiologia e produção do maracujazeiro amarelo

Abstract

Passion fruit is a tropical climate culture that exerts economic importance to Brazilian fruit growing, being cultivated in several regions of the country due to its adaptation to the different edaphoclimatic conditions. The objective of this study was to evaluate the growth, thermal requirements at the phenological stages, phyllochron, plastochron, substrate fertility, NPK levels in plants, physiological and productive aspects of yellow passion fruit irrigated with irrigation depths and hydrogel polymer. The experimental design was a randomized block with a factorial arrangement 2 × 5, relative to the soil without and with hydrogel polymer and five irrigation depths corresponding to 60, 70, 80, 90 and 100% of the ETc. The analyzed variables were growth, thermal accumulation, substrate fertility, NPK contents in the leaves, physiology and production in yellow passion fruit plants. The results were submitted to analysis of variance by the "F" test and the irrigation depths were submitted to regression analysis using SAS© software version 9.3. The growth in height, main stem diameter and number of leaves grew with the age of the plants after the transplant of the seedlings. The increase in water depths reduced thermal time in °C day, transplanting period pruning of the main stem and side branches and emission of floral buds fertilization of flowers increased the phosphorus content to the depths 79% of Etc. Irrigation depths, regardless of the substrate without or with hydrogel polymer, did not interfere in the accumulation of NPK in the leaves of the plants. The increase of the irrigation depth up to 81% of ETc provided stimulated the quantum yield of photosystem II, photosynthetic rate, stomatal conductance and efficiency in the use of water by yellow passion fruit plants. The highest number of fruits harvested, average fruit mass, yield per plant and yield of yellow passion fruit were obtained in the treatments with 100% of ETc in the substrate without hydrogel polymer.