Crescimento e produção do girassol em consórcio com feijão e milho sob diferentes lâminas de irrigação.

Abstract

Growth and production of sunflower intercropped with beans and corn under different irrigation depths. An adequate water and soil management is necessary to increase plant production and make feasible the agriculture. Under semiarid conditions, the irrigation and the culture intercropping presents important productive, economic and environmental advantages. However, results related with the irrigation of the sunflower intercropped with feeding cultures, in the semiarid, are scarce. Thus, the purpose of this work was to evaluate the behavior of the sunflower in relation to the levels of water replacement and arrangements of the Hélio 253 hybrid sunflower and food plants. The experiment was conducted in the field of the Human and Agrarian Sciences Center of the Paraiba State University, Campus IV, Catolé do Rocha, Paraíba, adopting a 4 x 3 factorial randomized blocks statistical design with four levels of available soil water capacity of the soil (60, 80, 100 and 120%) and three cultivation systems (isolated sunflower, sunflower + caupi bean and sunflower + corn) with, three replications, totalizing 36 experimental units. The analyzed variables were plant height, steam diameter, leaf area, crop production and water and soil use efficiency. Independently of the crop arrangement utilized, the available soil water content increased the growth and the production of sunflower being these greater when sunflower was cultivated isolated. On the intercropping arrangements, apparently, the corn competed more for resources than the beans. The land use efficiency in the intercropping arrangements, evaluated by the Efficient Use of the Land Index, showed the viability of this technique for the local farming. Irrigation with 90 to 93 % of the available soil water capacity provided the maximum water use efficiency for all crop systems evaluated.