Fontes e doses de zinco no feijoeiro cultivado em diferentes 谷pocas de semeadura = Sources and doses of zinc in common bean cultivated in different sowing seasons

作者：Itamar Rosa Teixeira; Aluizio Borem; Alessandro Guerra da Silva; Hamilton Kikuti

来源：Acta Scientiarum - Agronomy, 2008.

• Phaseolus vulgaris
• rendimento
• aduba o
• micronutriente
• Phaseolus vulgaris
• yield
• fertilization
• micronutrient

Este trabalho teve por objetivo avaliar, em diferentes 谷pocas de cultivo a produ o do feijoeiro, submetido 角 aplica o foliar de fontes e doses de zinco. Foi utilizado o delineamento de blocos casualizados, em esquema fatorial 3 x 2 x 5, com quatro repeti es. Os tratamentos envolveram a combina o de tr那s safras de cultivo (inverno, 芍guas e seca), duas fontes de zinco (sulfato e cloreto de zinco) e cinco doses de zinco (0, 100, 200, 400 e 800 g ha-1), aplicadas via foliar, aos 25 e 35 dias ap車s emerg那ncia da cultura.Na safra de inverno, foram obtidos os maiores rendimentos de gr os e de seus componentes (n迆mero de vagens por planta e n迆mero de gr os por vagem) e teor foliar de zinco, comparativamente, 角s safras das 芍guas e seca. N o houve efeito da intera o entre 谷pocas desemeadura, doses e fontes de zinco. Em solos com teor de Zn pr車ximo de 2,1 mg dm-3, n o houve aumento de produtividade para o feijoeiro com a utiliza o de cloreto ou sulfato de zinco, aplicados via foliar. This work was carried out with the objective of evaluating dry bean yield in different seasons, submitted to foliar application of different sources and doses of zinc. A randomized block design with four replications was used in a 3 x 2 x 5 factorial arrangement. The treatments were formed by the combination of three growing seasons(※fall/winter§, ※spring/summer§ and ※fall/summer§ seasons), two zinc sources (zinc sulfate and zinc chloride) and five zinc doses (0, 100, 200, 400 and 800 g ha-1), divided into leaf sprayings at 25 and 35 days after emergence (DAE). For the winter crop, a greater increasewas observed in grain yield, its main components (number of pods per plant and number of grains per plant) and leaf-zinc content, as compared to the other two seasons. There was no interaction between growing seasons, doses and sources of zinc. In soils with zinc contentof 2.1 mg dm-3, the addition of this nutrient by foliar application did not result in increase of bean yield.