| Popis: |
Water content of summer maize hybrids grown in China is too high at harvesting stage, which limits the development of grain mechanical harvesting technology. Spraying the desiccant can regulate physiological process of crop grain filling and reduce water content at harvest. We explored the effects of spraying the desiccant on the dehydration process, grain moisture, and grain quality of summer maize hybrids differing in maturity. Spraying the desiccants reduced dry matter accumulation in different organs of maize, with strongest reduction of middle-late maturity hybrids. Dry matter transfer to the grains of the plants and the harvest index was improved, but with no changes of grain quality. The dehydration rate of grains was positively correlated with the rate of dehydration in diffe-rent organs. The dehydration rate of grains after spraying the desiccants was significantly positively correlated with the rate of dehydration of stems and sheaths. With no negative effects on yield, spraying the desiccant increased the total dehydration rate, shortened the time from flowering to physiological maturity, and increased the time from physiological maturity to harvest, which was beneficial to the further reduction of grain moisture in the later stage. The possibility of grain mechanical harvesting was increased. The economic benefits of spraying the desiccants on mechanical grain harvest of summer maize hybrids differing in maturity were not significantly different from those of ear mechanical harvesting. The economic benefits of middle-late maturity hybrids were higher than those of early maturity hybrids. Spraying desiccant may improve the possibility of grain mechanical harvesting.目前,我国种植的夏玉米品种收获时籽粒含水率过高,限制了玉米机械粒收技术的发展。喷施脱水剂可以调控作物籽粒灌浆生理过程,降低收获时的籽粒含水率。本试验研究了喷施脱水剂对不同熟期夏玉米品种脱水过程、收获期籽粒含水率和籽粒品质的调控作用。结果表明: 喷施脱水剂减少了玉米各器官的干物质积累量,促进了植株向籽粒中的干物质转移,提高了收获指数,而且对籽粒品质没有显著影响。相关性分析显示,籽粒脱水速率与各器官脱水速率呈正相关,喷施脱水剂后籽粒脱水速率与茎鞘脱水速率呈极显著正相关。喷施脱水剂在产量没有显著降低的前提下提高了总脱水速率,缩短了开花期至生理成熟期的时间,增加了生理成熟期到收获的时间,有利于后期籽粒含水率的进一步降低,为玉米机械粒收提供了更大的可能性。不同熟期夏玉米品种喷施脱水剂进行机械粒收的经济效益与机械穗收相比没有显著差异,中晚熟品种的经济效益高于早熟品种。因此,收获前合理喷施脱水剂可以作为玉米机收籽粒的一种可行性配套技术。. |
