Effects Of Potassium On Grain Yield And Quality Formation In Weak-gluten Wheat

Soil potassium effectiveness, the effects of potassium on wheat growth and development, grain yield and quality, and potassium application techniques have been studied by many scholars at home and abroad. However, different studies selected different varieties, test soil fertility levels, and potassium rates, the results were different. And less study was done before in weak-gluten wheat. The effects of potassium on grain yield and quality formation in weak-gluten wheat varieties Ningmai13, Yangmai15 and Yangfumai 2 were studied at the experiment field of Jiangsu Provincial Key Lab of Crop Genetics and Physiology of Yangzhou University from 2005 to 2006. The main results were as follows.1. In this experiment, different ratios of N:P:K had different effects on plant characteristics in weak-gluten wheat. Increasing potassium application ratio properly could raise leaf area, tiller number, secondary root number, root length, root surface area and root volume, so photosynthetic production capacity strengthened and dry matter accumulation amount increased. But too high proportion of potassium was not good for the growth of plant above ground and root system at seedling stage, and grain yield and quality were negatively affected. The suitable N:P2O5:K2O ratio was 1:0.6:0.6.2. Under the condition of nitrogen and phosphorous being properly applied, raising potassium application amount or top-dressing potassium ratio could increase grain yield and protein content. But excessive amount of applied potassium or top dressing potassium would result in the decrease of grain yield and protein content. The proper ratio of N:P2O5:K2O was 1:0.6:0.6 and the suitable ratio of basal to top dressing potassium was 5:5 in Yangfumai 2 or 7:3 in Ningmai 13 and Yangmai15, which could result in high grain yield and good quality.3. Under the condition of nitrogen and phosphorous being applied, raising potassium application amount or top-dressing potassium ratio reasonably could increase NPK contents and accumulation amounts in plants at maturity.4. In order to get high grain yield with good quality in weak-gluten wheat, the suitable application ratio of N: P2O5 : K2O was 1:0.6:0.6, and the reasonable ratio of basal to top dressing potassium was 7:3 or 5:5.