AGRO-ECONOMIC EFFICIENCY OF THE INTERCROPPING OF CARROT X COWPEA-VEGETABLE UNDER DIFFERENT SPATIAL ARRANGEMENTS AND POPULATION DENSITIES

ABSTRACT The objective of this study was to evaluate the agro-economic efficiency of the intercropping of carrot with cowpea-vegetable under different spatial arrangements and population densities in the semi-arid conditions of the Brazilian Northeast. The study was conducted at the "Rafael Fernandes" Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA) during the period July 2013 to February 2014. The experimental design was of randomized complete blocks with four replications and treatments arranged in a 3 × 4 factorial scheme, where the first factor consisted of spatial arrangements (2:2; 3:3 and 4:4) and the second factor by population densities of cowpea-vegetables (100, 80, 60 and 40% of the recommended population in sole crop [RPSC]). All treatments were fertilized with roostertree (Calotropis procera [Ait.] R.Br.), which is a spontaneous species of the Caatinga biome. The indices of agronomic efficiency of the intercropping systems assessed were: land equivalent ratio, productive efficiency index and score of the canonical variable. The following economic indicators were also evaluated: gross income, net income, rate of return and profit margin. The agro-economic efficiency of the intercropping system of carrot with cowpea- vegetable was influenced by the spatial arrangements, with the 2:2 arrangements standing out from the others. The greatest agro-economic efficiency of the intercropping of carrot with cowpea-vegetable was obtained in the population density of 100% of the RPSC when the value of the productive efficiency index was 0.75.