Effects Of Plant Density And Nitrogen On Yield And Agronomic Traits Suitable For Mechanical Harvest For Winter Rapeseed In The Middle Reaches Of Yangtze River

This experiment was conducted simultaneously in Yangluo exp. base in Wuhan, Hubei Xiaochangcounty and Anhui Chaohu in the year of2011/12and2012/13. Zhongshuang11and Dadi55were used asexperimental matetials to carry out the experiment aimed at systematically studying the effects of nitrogenand plant density on yield and agronomic traits suitable for mechanical harvest for winter rapeseed. Usingtwo factors secondary saturated D-optimal design to optimization rapeseed cultivation and providing atheoretical basis for the realization of high-yielding oilseed rape and mechanized harvesting. The results wereas follows:1Effect of Nitrogen and plant density on the height of the rapeseedWhen the plant density is48,000~56,000per667m2and the nitrogen fertilizer is14.4~18.00kg per667m2,the height of Zhongshang11rapeseed is up to195cm;while the height of Dadi55rapeseed is higherthan182cm when the plant density is48,000~56,000per667m2and the nitrogen fertilizer is12.60~16.20kgper667m2.2The effect of Planting Density and Nitrogen Coupling on the first branch site of rapeseedWhen the plant density is40,000~48,000per667m2and the nitrogen fertilizer is3.6~7.2kg per667m2,the first branch site of Zhongshuang11rapeseed is at a higher position; While the first branch site of Dadi55rapeseed is at a higher position when the plant density is32,000~40,000per667m2and the nitrogenfertilizer is14.4~18.0kg per667m2.3The effect of Planting Density and Nitrogen Coupling on the number of valid branches ofrapeseedWhen the plant density is29,300~36,000per667m2and the nitrogen fertilizer is10.20~13.80kg per667m2, there is as more as7.39valid branches of Zhongshuang11rapeseed; While the number of validbranches of Dadi55rapeseed is about8.50when the plant density is29,300~37,300per667m2and thenitrogen fertilizer is10.20~13.80kg per667m2.4The effect of Planting Density and Nitrogen Coupling on the yield of rapeseedWhen the plant density is36,000~44,000per667m2and the nitrogen fertilizer is10.20~13.80kg per667m2, the yield of Zhongshuang11rapeseed is up to3,350.00kg per hectare; while the yield of Dadi55rapeseed is more than3,000.00kg per hectare. When the plant density is36,000~44,000per667m2and thenitrogen fertilizer is14.40~18.00kg per667m2.5The effect of Planting Density and Nitrogen Coupling on the thousand-grain weight of rapeseedsWhen the plant density is32,000~40,000per667m2and the nitrogen fertilizer is9.00~12.60kg per667m2, the thousand-grain weight of Zhongshuang11rapeseed is on a higher level and up to4.7g;whilethe thousand-grain weight of Dadi55rapeseed is more than4.05g when the plant density is32,000~40,000per667m2and the nitrogen fertilizer is11.40～15.00kg per667m2.6The effect of Planting Density and Nitrogen Coupling on mechanical harvest lost weightWhen the plant density is32,000~57,300per667m2and the nitrogen fertilizer is9.00～14.40kg per 667m2, the mechanical harvest lost weight Zhongshuang11reached to the lowest value, which is lowerthan74.00kg/hm2; while the lowest mechanical harvest lost weight of Dadi55could reach to64kg/hm2,when the plant density is48,000~60,000per667m2and the nitrogen fertilizer is3.00～6.60kg per667m2.The main conclusions：When the plant density is32,000~40,000per667m2and the nitrogen fertilizer is9.00~12.60kg per667m2,both the rapeseeds of Zhongshuang11and Dadi55have the common features:thinner stalk,lessbranches,higher position and shorter of the branches, etc, which are conducive to the mechanical harvestingof the rapeseed.Compared with the conventional seedling transplanting of the rape, it is easier to achieve high densitythrough and longer main roots by mechanical drilling. At the same time, under reasonable density itshortened the growing period by7-14d and can also easier get higher yield. The total loss weight ofmachinery Combine Harvest (one-time gains) is hardly affected by mechanical drilling while the oil contentof the rape seeds was enhanced compared with the conventional seeding transplanting.