Effect of soil moisture and fertilization on Pérola pineapple in Coastal Tableland areas of Brazil. (83)

Abstract

Most of the pineapple [Ananas comosus L. (Merrill)] production areas in Brazil, the Coastal Tablelands included, have a dry period causing water deficit to the crop. Therefore, irrigation is important to assure quality fruit production, even for off-season harvests. In addition, nutrient levels must still be determined for the irrigated crop. The interactive effects of soil moisture and fertilization on yield and fruit quality of Pérola pineapple was studied in an experiment carried out on a yellow Latosol at the Experimental Field of Embrapa Cassava & Fruits, Cruz das Almas, Bahia, Brazil. This site has an altitude of 220 m, an average annual rainfall of 1170 mm, and an average temperature of 24.5°C. The planting density was 51 280 plants ha-1. The experimental design was a split-plot in randomized blocks with five treatments (fertilization levels) and five sub-treatments (irrigation levels: 608 mm, 568 mm, 525 mm, 468 mm, and 334 mm yr-1). An effective precipitation of 671 mm yr-1 occurred during the experimental period. The fertilization levels were 0, 0.5, 1, 2, and 3 times the amount of 250 kg of N + 40 kg of P2O5 + 120 kg K2O ha-1, applied as castor oil cake, urea, simple superphosphate, and potassium chloride, during the second, fifth, and eighth month after planting. The irrigation was done by sprinklers in line (Line Source), spaced 6 m apart. Flowering was forced at 10 months and fruit harvests occurred during the 16th month after planting. Results showed a significant influence of water and fertilization levels on yield and fruit quality, but there was no significant interaction between the factors studied. Using a production function, according to the quadratic model, the maximum yield was estimated at 54.86 t ha-1, for a irrigation lamina of 596.28 mm and a fertilization 2.47 times higher than the one recommended for rainfed conditions.