Effects Of Phosphorus On Grain Yield And Quality Of Weak-gluten Wheat

To investigate the effects of phosphorus on grain yield and quality of weak glutenwheat, weak gluten wheat varieties Yangmai 9,Ningmai 9 and Yangmai 13 were used astest materials, and grain yield and quality formation characteristics were studied. Theexperiment was carried out on the field of Taixing Regional Agriculture ResearchInstitute of Jiangsu, and on the experimental field of Crop Cultivation and PhysiologyKey Laboratory of Jiangsu Province, Yangzhou University in 2003-2005. The mainresults were as follows.1. The amount of phosphorus application and the ratio of based to top dressingphosphorus could significantly affect grain yield and yield components. Grain yieldhad a quadratic relationship with phosphorus application amount With the increasing ofphosphorus application amount below 108 kg/hm²(P₂O₅), grain yield increased. Underthe same phosphorus application amount, the ratio of basal to top dressing phosphorus5:5 could get the highest yield.2. Grain protein content in all treatments showed a high-low-high change. Grainprotein content declined to the lowest on the 21st day after anthesis (DAA). At earlygrain filling stage, albumin and globulin contents were relatively high, then declinedgradually with grain filling; while gliadin and glutenin contents increased gradually withgrain development. Albumin and globulin were mainly formed at early grain fillingstage, whereas gliadin and glutenin were at middle and late stages.3. The contents and the accumulation amounts of amylose, amylopectin and starch ingrains showed "S" type dynamics with grain development, while the accumulation rate of amylose, amylopectin and starch was an unimodal distribution. The maximumaccumulation rate of amylose, amylopectin and starch appeared on the 21-28th DAA4. With the increasing of phosphorus application amount less than 108 kg/hm²(P₂O₅),grain protein content increased, but amylose, amylopectin and starch contents decreased.When phosphorus application amount was more than 108 kg/hm²(P₂O₅), grain proteincontent decreased, while amylose, amylopectin and starch contents increased. Under thesame phosphorus application amount, with the rising of top dressing phosphoruspercentage below 50%, grain protein content increased, while amylose, amylopectin andstarch contents decreased, but when the percentage was greater than 50%, with the rising,grain protein content decreased, whereas amylose, amylopectin and starch contentsincreased.5. Both N and P contents in plants had a peak value during the period fromemergence stage to wintering. Plants had the greatest N and P contents in the treatment of108Kg/hm²(P₂O₅) phosphorus application amount or basal to top dressing phosphorusratio 5:5.6. According to the results above, it might be suggested that the suitable phosphorusapplication amount was 108 kg/hm²(P₂O₅) and the reasonable ratio of basal to topdressing phosphorus was 5:5, which could result in high yield and good quality forweak-gluten wheat.