Effect of Sowing Date and Planting Density on Population Traits and Grain Yield of Winter Wheat Cultivar Yumai 492198.

In order to provide suitable cultivation measures for the large-scale extension of wheat cultivar,Yumai 49-198,the effects of sowing dates and planting densities on population traits,grain yield and yield components were investigated.The results indicated that sowing date and planting density could adjust population characters.The highest stem number decreased with the delay of sowing date and reduction of planting density.Of all sowing dates,the final ear number of the early sowing date was less.The highest leaf area idex decreased with the delay of sowing date.The leaf area idex of the early sowing date decreased faster than that of the other sowing dates after booting stage.The dry matter accumulation after anthesis was the most when Yumai 49-198 was planted at October 12,followed by the late sowing date and the early sowing date.The effect of sowing date and planting density on grain yield and its components was significant.The influence of planting density on yield component is bigger than that of sowing date.Of all sowing dates,the average yield sown at October 12 was significantly higher than that sown at October 5,but not significant higher than that sown at October 19.Of all planting densites,the average yield of the density of 1 950 thousand seedlings per hectare was the highest,but not significant to that of the density of 2 700 thousand seedlings per hectare.According to this result,when the highest leaf area idex and dry biomass accumulation were around 9.5 and 21 t per hectare,respectively,grain yield of Yumai 49-198 could reach up to 9 000 kg per hectare,while the responding suitable sowing date respectively was middle October and planting density was 1 950~2 700 thousand seedlings per hectare.