Coeficientes da cultura e produtividade do consórcio de milho caatingueiro com feijão-de-porco e do repolho plantado na palhada

Abstract

The study of crops water demand throughout its development cycle enables the rational use of water, and this scarce study for maize intercropped with bean-to-pig and cabbage grown in maize straw. The objective of this work was to determine the crop evapotranspiration (ETc) and crop coefficients (Kc) of “caatingueiro” corn under monoculture and intercropping system with bean-to-pig, , and “fuyutoyo” cabbage planted on the straw, and to check the influence of the consortium in the production of corn and cabbage. The study was conducted in Seropédica-RJ, using weighing lysimeters, the Kc values were determined by the ratio between ETc and the reference evapotranspiration (ETo). The ETo was estimated by the FAO Penman-Monteith model. The ETc values were calculated using the water balance of the lysimeter-cropp-soil system. The cycle caatingueiro corn intercropped with jack bean and monoculture was March 18 to June 25, the Kc values were calculated for the four stages of crop development. The corn planted in three areas, one with corn intercropping and jack beans with full irrigation (C100), the other with intercropped with deficit irrigation (CD75) and the last with monoculture (Mon). Four samples were taken throughout the cycle to analyze the leaf area, plant height and cob insertion and end of the cycle data of productivity and of water use efficiency (WUE) were measured. The fuyutoyo cabbage was transplanted from the tray to the area 33 days and the cycle after transplant lasted from July 17 to October 26, the Kc values were calculated for the four stages of development. The Kc values for each phase of crop development in the intercropping system were: I (0.78); II (1.06); III (1.10) and IV (1.01), for the monoculture system, the kc values were: I (0.62); II (0.92); III (1.27) and IV (0.89). The corn had a Degree-Days accumulation of 1416.5 ° C throughout cycle, there was not significant difference in leaf area and number of corn cob between the three areas, The C100 area showed smaller values of plant height for all measurements, since the CD75 was lower than Mon only the first measurement. The productivity of C100 (6937.17 kg / ha) did not differ from that found in Mon (6055.34 kg / ha) and was higher than that found in CD75 (4328.91 kg / ha). The C100 showed higher WUE than CD75 and was similar to values found for Mon. The Cabbage has kc values for each phase of crop development: I (1.02); II (1.03); III (1.05) and IV (1.01) and had a degrees-day accumulation of 1439.2 ° C. The productivity cabbage RMon (34.76 T / ha) was higher than the area RC100 (18.99 T / ha), the WUE was lower in RC100. The RCD75 did not differ in the statistical tests. Corn consortium with beans had good result in corn yields in the area C100 and lower productivity in CD75 area, and had no satisfactory result in cabbage productivity in the area RC100