倒伏是玉米生产中常见的现象。玉米倒伏后加大了收获难度和成本，本研究通过调查玉米田间倒伏率与机械粒收产量损失率，建立倒伏率与机械粒收损失率之间的量化关系，通过改变割台高度和收获方向等措施，明确不同收获方式对产量损失的影响。结果表明，倒伏对玉米产量影响主要表现为落穗损失，与根倒相比，茎折对玉米产量损失的影响更大，茎折每增加1%，落穗率增加0.28%；根倒每增加1%，落穗率增加0.17%。茎折发生的部位越低，落穗率越高。收获时降低收获机割台可以减少部分产量损失，但是容易造成收获机割台堵塞，收获速度和效率大幅下降。与顺倒伏方向和垂直倒伏方向收获相比，逆倒伏方向收获的落穗损失最低。
英文摘要:
Lodging is a common problem during maize production. Lodging increases the difficulty and costs of harvesting. The experiment treatments included maize cultivars, plant density and fertilizer were conducted. The rate of stalk lodging, root lodging, ear and kernel loss were investigated to determine the quantitative relationship of lodging rate with grain loss in mechanical grain harvest. The effect of different harvesting methods on yield loss are clarified by changing the header height and harvest direction. The results showed that, the ear loss was a major part of grain yield loss. The stalk lodging had a greater impact on maize ear loss than root lodging in mechanical grain harvest. Ear loss ra/te increased by 0.28% when stalk lodging rate increased each 1%, ear loss rate increased by 0.17% when root lodging rate increased each 1%. The ear loss was higher in lower position of stalk broken than that in higher position. Lowering the harvester header decreased ear loss rate, but this was easily to cause blockage of the header, this greatly reduced harvest efficiency. When the harvesting direction was opposite to the direction of plant lodging, the ear loss was lowest, however, this was also easily to cause the blockage of the header.
;
