PRODUCTION COMPONENTS OF Vigna unguiculata (L. Walp) IRRIGATED WITH BRACKISH WATER UNDER DIFFERENT LEACHING FRACTIONS

ABSTRACT The objective of this work was to evaluate the production components of cowpea (Vigna unguiculata L. Walp) subjected to irrigation with brackish water and different leaching fractions. The experiment was conducted in a lysimeter system of the Department of Agricultural Engineering of the Federal Rural University of Pernambuco, Recife campus. The treatments, consisting of two water salinity levels (ECw) (1.2 and 3.3 dS m-1) and five leaching fractions (0, 5, 10, 15 and 20%), were evaluated using a completely randomized design in a 2x5 factorial arrangement with four replications. The variables evaluated were: number of pods per plant, 100-grain weight, number of grains per pod, grain and shoot dry weight, grain yield and harvest index. The soil salinity increased with increasing salinity of the water used for irrigation, and reduced with increasing leaching fraction. The salinity of the water used for irrigation influenced only the variables number of pods per plant and grain yield. The estimated leaching fractions of 9.1% and 9.6% inhibited the damage caused by salinity on the number of pods per plant and grain yield, respectively. Therefore, the production of V. unguiculata irrigated with brackish water, leaching salts from the plant root environment, is possible under the conditions evaluated.