Effects Of Different Cultivation Management Models And Nitrogen Application Rate On The Characteristics Of Floret Development And Grain Set In Winter Wheat

Improving the grain number is one of the important ways to high yield of wheat production. so the research and development of wheat flower formation and cultivation of grain number of control measures has theoretical and practical significance on wheat high yield, quality, efficiency, safety. The objectives of experiment 1 were to investigate the effects of different cultivation management modes on the characteristics of floret development and grain set of winter wheat cultivar /Yumai 48-198, therefore, to suggest a reasonable cultivation and management model in wheat production in Henan high-yield irrigation areas. The four different cultivation and management modes were Farmers Planting Cultivation mode, Low-cost and High-efficiency cultivation and management mode,Super high yield cultivation mode, High yield and high efficiency cultivation and management mode. Experiment 2 were conducted in the Science and Technology Demonstration Park of Henan Agricultural University during 2013-2014 growing seasons. The experiment involved the wheat cultivar Yumai49-198 and three nitrogen level treatment. The samples of different nitrogen levels N0, N90, N180 collected were observed to record: the young spikelets’ differentiation process of the main stem /the characteristics of young spikelet differentiation and the number of grains at different spikelet positions(basal, central, and apical) at different stages.The main results were as follows:1 the effects of different cultivation models on the characteristics of floret development and grain Set of winter wheatThrough on development process of different spikelets(basal, central, and apical) spikelet of winter wheat, and the results showed that wheat young panicle differentiation process, Optimized cultivation and management effectively promote wheat panicle development process and the quantity of flowers of each Spikelet development, especially for the Central and the base spikelets, and the effect of Super high yield and High yield and high efficiency cultivation and management mode are significant, providing a good foundation of improving grain of each spikelets. Studied the dynamic of floret initiation characteristics and grain Set of different cultivation models, and the results show that The dynamic of floret initiation in different cultivation management modes showed quadratic rising curve, floret degeneration and infertility showed the linear decrease with GDD after sowing, but the wheat of different cultivation management modes were in the parameters of the equations. the wheat of HH、SH and JH effectively increased the fertile florets and seed grains, and significantly increased the spikelet set, floret set and grain set, and HH was significantly higher than other models.With flowers growth progress, the trend of different cultivation models wheat per stem dry weight、 Stem nitrogen showed growth, while a flowers dry weight and nitrogen accounting per stem account first and then reduce, optimized cultivation models promote floret dry weight 、nitrogen content, perfect florets and spike dry weight、nitrogen accumulation and the effect of improving perfect flowers per square meter are obvious, and the cultivation management of high yield and high efficient effectiveness were significant. The final number of spikelets and perfect florets of anthesis, spike dry matter accumulation、nitrogen content and perfect flowers after five days of anthesis were significant positive correlation, and the correlation coefficient was above 0.9.Optimizated cultivation and management model ensure nutrient demand for wheat growth stages, to ensure the After flowering the accumulation of photosynthetic products, improved the contribution rate of post-anthesis assimilated dry matter to grain yield in order to obtain a higher yield. This study showed that, compared with FP, Optimizated cultivation and management model improved production mainly because of the differences in the number of spikes and spike, super high yield and High yield and high efficiency cultivation and management mode as commonly used in the cultivation and management mode, had more spikes and more grain number, and the final yield was significantly increased. While super high yield ensured adequate supply and distribution ratio of assimilation at floret stage, but put more resources; High yield and high efficiency cultivation and management mode efficient all-optimized yield cultivation techniques in one, able to balance the relationship between the three elements of production, can get higher set of fertile florets and grain number and improve the yield of wheat.2 The development of different nitrogen levels flowers and seed Difference AnalysisThe dynamic of floret initiation in different nitrogen levels showed quadratic rising curve, floret degeneration and infertility showed the linear decrease with the growing-degree-days(GDD) after sowing. This comprehensive study were analysed in detail floret development in wheat as affected by and found that the wheat of N90、N180 effectively increased the fertile florets by decreasing abortion rate. the basal spikelet florets abortion rate decrease by 22.60% and 70.24% respectively, the central spikelet florets abortion rate decrease by 38.68% and 57.61%, the apical spikelet floret’s abortion rate decrease by 25.58% and 51.15%. N90, N180 raised the percentage of fertile florets in different levels and significantly increased the wheat grain,especially the increased range of the N180 is the largest. Further analysis, N180 can significantly promote florets grain-setting at different floret position of the different spikelets, especially promote producing seeds of the No2,3,4 floret position which are weak florets. Reasonable nitrogen strategy can obviously reduce the different spikelet fertile floret abortion rate, so as to improve the grain set rate of fertile florets per spike and the final grain number.Through the the variance analysis of flower dry weight and nitrogen content development of different tillering wheat in nitrogen fertilization, appropriate amount of nitrogen is not only able to increase dry weight and nitrogen content of each tiller floret per stem in different developmental periods, but also reduces the death of Invalid wheat tillers and flowers, and the N180 is most significant. Reasonable amount of nitrogen promotes dry weight, nitrogen accumulation and perfect florets in anthesis, and plays an important role of increasing the number of mature grain nitrogen accumulation in each spike. The final number of spikelets and perfect florets of anthesis、 spike dry matter accumulation、nitrogen content were significant positive correlation, mature grains per spike and perfect flowers after five days of anthesis were significantly positive correlation.