The Effects of Boron, Zinc, Manganese and Iron Application on Seed Yield and Yield Components in Adzuki Bean

Abstract

To clarify the optimal application of trace elements to Adzuki bean, the effect of fertilizers containing boron, zinc and manganese (Experiment 1); and, that containing iron and zinc (Experiment 2) on the yield of two Adzuki cultivars was investigated. The cultivars were grown in Hokkaido at Ebetsu on gray upland soil and at Obihiro on volcanic ash soil. At both sites, the pre-experiment soil contents of boron, zinc, and iron were near the lower limit of the soil diagnostic standard. Application of fritted trace elements, Agri-Ace (citric acid-soluble boron , zinc and manganese), and water soluble fertilizer (water-soluble boron, zinc and manganese) increased yield by 19%, 13%, and 8%, respectively, in Experiment 1. The yield increase reflected increased absorption of boron. In Experiment 2, soil application and foliar application of soluble iron and zinc increased yield by 20% and 38%, respectively. Zinc and iron absorption from the foliar application was expected to be higher than that from the soil application. The maximum increase in the soil concentration of boron, zinc, and iron after harvest was 0.2, 1, 5 ppm, respectively, and none of the trace elements accumulated to toxic concentrations. The two experiments indicated that application of boron at 360 g/10 a and zinc at 900 g/10 a was effective in increasing Adzuki bean yield.