Fontes e doses de zinco na nutrição e produção de feijão-comum e mamona em consórcio

Abstract

Intercropping is commonly used in Brazil, specially at small rural properties. Nevertheless the real advantage of this technique in relation to monocropping turns more evident when the cultivation concerned presents differences between their demands of available resources, qualitative or/and quantitative. Also, satisfactory productivity of the involved cultures will be archived only with the knowledge of the real nutritional demands of the intercropping cultures. Facing that, this work aimed to evaluate nutrition, agronomical characteristics and the physiologic quality of the common bean and castor bean seeds used in intercropping subjected to different sources and doses of zinc in. The randomized block design was used in a factorial arrangement 2 x 5 + 2 with three repetitions. The treatments were composed of two zinc sources (zinc oxide = 15% de Zn and zinc sulfate = 20% de Zn) combined with five zinc doses (0,0; 1,0; 2,0; 4,0 and 8,0 kg ha-1 of Zn on the ground) in common bean and castor bean intercropping plus additional treatments in the monocropping of bean and castor bean. It concludes that: a) the fertilizing using zinc affected the leaf percentage of phosphorus, calcium, magnesium, manganese and zinc in these cultures specially zinc sulfate. In general, the leaf nutrient content in castor beans and beans submitted to intercropping under sources and doses of zinc were within the range considered suitable for the development of both crops; b) fertilization with 4.1 and 4.9 kg/ha of zinc led to higher yields of beans and castor beans seeds under intercropping with maximum heights of 1,850 kg/ha and 1951 kg/ha for the respective cultures; c) there was no difference in nutrition and the agronomic part of the bean and castor bean cultivated in monocropping and intercropping systems; d) the intercropping of common bean and castor bean system was more efficient than the monocropping according to the values of UET - 1.98 for the different doses of zinc added by means fertilizer.