Produtividade e qualidade de frutos de goiabeira (Psidium guajava L.) irrigada por gotejamento.

Abstract

Due to the poor distribution of rainfalls during the production cycle of guava in Santa Maria, RS, it becomes increasingly necessary to use supplementary irrigation, as a tool that can alleviate the effects of drought for the crop. In this way, the irrigation has proven to be one of the most recommended methods for guava. Thus this study aimed to evaluate the increments of productivity and quality of guava fruits drip irrigated in the municipality of Santa Maria, besides evaluating the effect of climatic factors on the quality of fruits (pH, soluble solids and titratable acidity), and propose an efficient way to manage irrigation on local conditions. The experiment was installed in the Fruticulture Sector of Polytechnic School of the Universidade Federal de Santa Maria in Rio Grande do Sul. The study was made on randomized complete block design distributed in five treatments with six repetitions. The treatments consisted of applying water depth by drip, corresponding to replacement of 0, 40, 60, 80, and 100%, being applied to each 20 mm of maximum cumulative evapotranspiration (ETmac) by the culture of guava. As for data analysis of pH, total soluble solids (SST) and titratable acidity (ATT) of the fruits, treatments were arranged in a randomized block design but in factorial arrangement 5x3, being five irrigation depth and three cropping season fruits. The reference of evapotranspiration was estimated from the automatic data collected from Weather Station located at UFSM with the Penman Monteith equation. The results showed no statistically significant differences in the parameters, length, diameter, length / diameter relation, number of locules, mass, pH, SST and ATT of the fruits under the influence of irrigation water, however irrigation influenced the number of fruits per plant, productivity and the volume of fruit. It was also observed that the factors sunlight, solar radiation and air temperature interfered significantly in the chemical parameters of fruit.