Cultivo da pinheira (Annona squamosa L.) em função da disponibilidade hídrica na zona da mata Alagoana

Abstract

The sugar apple (Annona squamosa L.) is considered a very important fruit tree in the context of the northeastern semi-arid region because it is a potentially productive crop that generates income and employs labor in regions with problems of poor rainfall distribution, and understanding the response of this crop to the specific environmental conditions of the region is essential for improving agricultural management. The aim of this study was to determine the productivity and economic analysis of the pine tree as a function of different water availability in the soil, in Rio Largo - AL. The research was carried out during the dry season, from November 2021 to April 2022. The experimental area is located at the Campus de Engenharia e Ciências Agrárias (CECA) of the Federal University of Alagoas (9°27'58.7'' S; 35°49'47.2'' W; 127 m) in the municipality of Rio Largo, Alagoas. The experimental design adopted was entirely randomized (DIC), with five replications. Four irrigation treatments were tested, equivalent to L1: (dry), L2: 50%, L3: 100% and L4: 150% of crop evapotranspiration (ETC), totaling 20 experimental plots. The ETC was obtained by multiplying the reference evapotranspiration (ET0) and the crop coefficient (KC). Irrigation was carried out using 32 L h -1 micro-sprinklers spaced 3.0 x 3.0 meters apart. The crop's water balance was calculated using the Thornthwaite and Mather method on a decadal scale. In this study, the total water table was defined as total irrigation plus effective rainfall. The variables analyzed were: number of fruits per plant, fruit mass per plant (kg), average fruit mass (g), fruit diameter (mm), °Brix, yield (tha -1) and water use productivity (kg ha -1 mm-1). The average maximum air temperature during the research was 31.1°C, the average relative humidity was 70.5%, and the total accumulated rainfall was 505.2 mm. This resulted in an effective rainfall of 267 mm and, under rainfed conditions, a water deficit of 179 mm and a surplus of 238 mm were estimated. The accumulated ET0 was 732.5 mm and the ETC 353 mm in the 147-day period after pruning the pine tree. All the variables analyzed showed significant differences for the different amounts of water available in the soil. The highest number of fruits per plant (63 units) was obtained without applying any water. The maximum fruit mass per plant (12.85 kg), the highest average fruit mass (0.234 kg), the maximum fruit diameter (67.19 mm) and the highest value for soluble solids (18.25) were obtained with the application of 446.68 mm (95% of the CTS). The maximum productivity of the pine tree crop was 14,280 kg ha -1 with the application of 446.68 mm (95% of the ETC) and the maximum productivity of water use (31.98 kg ha -1 mm-1) was obtained with the application of 446.68 mm (95% of the ETC). The maximum physical productivity (MPP) of the pine tree is 12,825.93 kg ha-1 with an estimated total irrigation rate of 431.54 mm (effective rainfall + irrigation). The productivity of maximum financial efficiency (PMEF) of the pine tree crop, with an average price of R$ 4.39 reais per kilo, and the value of the millimeter applied of R$ 2.07 reais, is 12,825.68 kg ha-1 with a total irrigation depth of 430.48 mm (effective rainfall + irrigation). It can be concluded that irrigation is a promising alternative for growing pine cones in the Zona da Mata region of Alagoas. Keywords: Anonaceae; Production; Crop evapotranspiration; Economic profitability.