Study On Mechanism And Cultural Technique For High Yield And Good Quality Of Late-sowing Wheat

50 STUDY ON MECHANISM AND CULTURAL TECHNIQUE FOR hIGH YIELDAND GOOD QUAL1TYOFLATE-SOWING WHEAT Postgraduate: Yang Yong Supervisor: Prof. Guo Wenshan Prof. Peng Yongxin Prof. Feng Chaonian (Yangzhou Univ., Yangzhou, 225009) ABSTRACT The experminents were carried out to determine the effect of different densities and fertilizer managements on development~, diy matter pnxluction and distribution,nutrition absorption,yield formation and grain quality with Yangmei 158 and Yangmei 10æ•€in 1998-2000 in the crop cultivation and physiological key laboratory, Yangzhou University. The results were as follows: 1 .Compared with the optimal-sowing wheat ,the developmental progress was slow in the earlier stage,quick in the middle stage and stable in the later stage.Total leaf numbers and the effective tiller were reduced.Total floret nunibers,fertile floret numbers and grain numbers all had been decreased.Dry matter accumulation was lower in every growth stage.CGR(crop groth rate) was higher from jointing to anthesis and from anthesis to mature.The ratio of dry matter accumulation to dry weight of grain and economics index was higher.The trend of dry matter accuniulution was lower in the former and higher in the later.In the earlier stage of grain fihling(14d after anthesis),the intensity of filling was higher in middle stage and lower in later stage(14d to 28d after anthesis).The grain weight was lower.Insufficient spike numbers and lower grain weight were the main limitation for high yield. 2.The content of N(nitrogen) in the plant was increased remarkably with delay of the sowing date.Compared with optimal-sowing wheat,the peak of N uptake was mainly from jointing to anthesis and from anthesis to mature. the intensity of N uptake were doubled.The highest rate of N uptake was after anthesis.The N amount of population 51 and intensity after anthesis were both positively correlated to yield (r41.9054** 0.9051 * *) .The productivity of N was increased with the basic seedling numbers and N application rate in later stage at the identical basic seedling numbers,and was positively correlated to yield(r~09999**).P2O5 was absorbed mainly after antheis,and had the most accumulution with the treatment (360,3:3.5:3.5).K20 accumulution and uptake intensity were lower before jointing,and higher from jointing to anthesis,and the uptake intensity was doubled. 3 .The optimal basic seeding numbers was increased with the delay of sowing date. Spike number per hectare improved with the increase of N rate in the basic fertilizer ,grain number per spike improved with the amount of N in the later fertilizer. Per thousand grain numbers weight of the treatments of heavy amount in later fertilizer and equal amount in two stage was higher than the treatment of heavy amount in basic fertilizer one by different fertilizer mangement.The heavy amount in later fertilizer resulted in the maximum yield. The delay of the sowing date could improve the content of protein,wet gluten,and decline the ratio of straight and branch starch with the identical density and fertilizer management. T...