种植密度对冀东地区春玉米灌浆和脱水的影响

Effect of Planting Density on Grouting and Dehydration of Spring Maize in Eastern Hebei Province

【目的】研究不同种植密度对春玉米灌浆、脱水和产量性状的影响,为冀东地区春玉米高密度种植、提高产量提供科学依据。【方法】选用前期筛选出的立杆特性良好的宜机收品种(京农科728和MC812)进行耐密性试验,研究不同种植密度(60000、67500、75000、82500、90000株/hm^(2))对灌浆、脱水和产量性状的影响。【结果】随着种植密度增加,两个春玉米品种的穗数和产量基本呈上升趋势,均在90000株/hm^(2)种植密度下达到最大值;籽粒在灌浆期间百粒重表现出“慢-快-慢”S型上升趋势,灌浆速率和脱水速率都表现出先升后降的单峰曲线,且到达峰值的时间和变化趋势一致,峰值均出现在吐丝后26 d。茎秆和苞叶脱水速率出现先降后升的变化趋势,最大脱水速率和灌浆速率出现在60000~75000株/hm^(2)种植密度;随着吐丝天数增加,两个品种籽粒、茎秆和苞叶的含水率整体上均表现出“慢-快-慢”下降趋势,且60000~75000株/hm^(2)种植密度下的含水率比82500~90000株/hm^(2)种植密度低。【结论】为保证冀东地区春玉米高产,建议种植密度为90000株/hm^(2)。

【Objective】The effects of different planting densities on spring maize grouting,dehydration and yield characters were studied to provide scientific basis for high-density planting and yield increase of spring maize in eastern Hebei Province.【Method】The good varieties(Jingnongke 728 and MC812)with appropriate poling characteristics and suitable for mechanical harvesting screened in early stage were selected to conduct tightness resistance test,and five planting densities(60000 plants/hm^(2),67500 plants/hm^(2),75000 plants/hm^(2),82500 plants/hm^(2) and 90000 plants/hm^(2))were set.The effects of different planting densities on grouting,dehydration and yield characters were studied.【Result】With the increase of plating density,the spike number and yield of the two varieties showed an increasing trend,and both reached the maximum under the density of 90000 plants/hm^(2).The 100-grain weight of seeds showed a S-shaped(“slow-fast-slow”)upward trend during grain filling,the grain filling rate and dehydration rate showed a single-peak curve of“first rising then falling”,and the time to reach the peak value was consistent with the changing trend,and the peak value appeared on the 26th day after spinning.The rates of stem and bract dehydration showed a trend of decreasing first and then increasing.The maximum dehydration rate and filling rate appeared at the planting density of 60000-75000 plants/hm^(2).With the increase of silking days,the moisture contents of seeds,stems and bracts of the two varieties showed a“slow-fast-slow”decreasing trend on the whole,and the moisture content under the planting density of 60000-75000 plants/hm^(2) was lower than that of 82500-90000 plants/hm^(2).【Conclusion】To ensure high yield of spring maize in eastern Hebei Province,it is suggested that the planting density is 90000 plants/hm^(2).