夏玉米乳线位置与粒重及机械化收获关系的研究

The Relationship Between Milk Line Position and Grain Weight, Mechanized Harvest of Summer Corn

为研究黄淮海夏玉米乳线位置与粒重及机械化收获的关系,选用推广面积较大的8个品种(A、B、C、D、E、F、G、H)作为处理,测定其灌浆速率、百粒重、含水量及乳线位置等性状,并分析其相关性。结果表明:乳线位置在90%时籽粒灌浆已经结束,百粒重出现峰值,最高为43.02 g,灌浆时间与百粒重程正相关,乳线完全消失后,百粒重最大可降低8.66%;在粒重上升期处理间差异不显著,下降期处理D、E、H与其他处理间差异达极显著水平;脱水速率处理C、A与其他6个处理间差异显著;籽粒含水量与乳线位置呈负相关,乳线下移至90%,籽粒含水量在30%以下。影响夏玉米机械化收获籽粒的关键因素是收获时间,而不是品种;乳线位置下移至90%是夏玉米收获的最佳时间,收获过晚产量会有不同程度的降低。

To investigate the relationship between milk line position and grain weight, mechanized harvest ofsummer corn in Huang-Huai-Hai Region, we selected 8 varieties（A, B, C, D, E, F, G, H） with large plantedareas to measure the grain filling rate, 100-seed weight, water content and milk line position, and analyzed thecorrelation. Results showed that when the milk line position was 90%, the grain filling of all the 8 varietiesfinished and 100-seed weight reached the highest value, which was 43.02 g. A positive correlation appearedbetween the grain filling time and 100-seed weight. However, when the milk line position completelydisappeared, the 100-seed weight was largely reduced by 8.66%. There was no significant difference duringthe periods of grain weight rising, but in the periods of grain weight falling, the traits of D, E, H weresignificantly different with the other varieties and dehydration rate of C and A had significant difference withthe other six varieties. The water content of grain was negatively correlated with milk line position. When themilk line position was 90%, the grain water content was less than 30%. The key factor influencing themechanized harvest of summer corn is harvesting time, rather than the varieties. Moreover, milk-line positionof 90% is the best time for harvest; if the harvest is too late, the yield will be reduced with varying degrees.