Abstract
Summer buckwheat cultivation is expected to contribute to a stable production of high-quality, domestically produced buckwheat. However, the low yield is a serious problem. In this study, we examined the effects of foliar spraying of phosphite and micronutrients on the buckwheat yield and weed weight in farmers’ fields where buckwheat was sown from 30 March to 2 April, 2021. In experiment 1, the leaves were sprayed with phosphite on 17, 25 and 39 days after sowing (DAS). Foliar spraying of phosphite on 25 and 39 DAS, increased significantly at the 1% and 0.1% levels, the grain yield of buckwheat by 9.3 and 43.1 g/m2, respectively. In experiment 2, the leaves were sprayed with micronutrients on 17 DAS or with phosphite on 47 DAS. Foliar spraying of phosphite significantly increased at 0.1% level the grain yield of buckwheat by 38.2 g/m2, but spraying of micronutrients had no effect. In experiment 3, the leaves were sprayed with phosphite on 26, 40 and 47 DAS. The grain yield of buckwheat significantly increased from 18.7 g/m2 to 94.7 g/m2. Although the phosphorus and potassium contents of the soil before cultivation were appropriate, we discussed the hypothetical effects of a shallow hard soil layer and high groundwater level on phosphorus deficiency in buckwheat. Moreover, the foliar spraying of phosphite fertilizers did not increase the weight of weeds, which was a concern among the farmers. These findings suggested that the foliar spraying of phosphite fertilizers improves buckwheat yield.
