不同类型青贮玉米品种子粒和全株含水率动态变化特性

以8个生产主推青贮玉米品种（专用型4个、粮饲兼用型4个）为研究对象，探究分析不同类型青贮玉米品种的子粒与全株含水率动态变化特性。结果表明，玉米子粒乳线位置处于1/4、2/4、3/4和4/4时，对应处于授粉后36.8 d、47.0 d、56.4 d和63.6 d，子粒平均含水率为48.6%、39.3%、34.2%和31.1%，全株平均含水率为76.9%、70.2%、60.7%和56.5%。8个品种全株含水率由70%降至60%平均需14.0 d，其中专用型品种平均需16.7 d，比粮饲兼用型品种所需时间长5.4 d。专用青贮玉米品种适收期全株含水率70%~60%对应子粒乳线位置1/2~3/4，其适收期较粮饲兼用型品种长5 d；青贮玉米品种收获期内子粒生理降水速率和全株含水率降低速率相对较低，是京科青贮516、雅玉26、郑单958、京科968适收期相对较长的原因。

Dynamic Changes of Grain and Whole Plant Water Content of Different Silage Maize Varieties

Eight main maize varieties were used in order to study and clarify the dynamic changes of the grain and whole plant water content for different types of silage maize varieties. The results showed that at the milk line position of 1/4, 2/4, 3/4 and 4/4, the tested eight varieties were averaged 36.8, 47.0, 56.4 and 63.6 d after pollination. The averaged grain water content was 48.6%, 39.3%, 34.2% and 31.1%, and averaged whole plant water content was 76.9%, 70.2%, 60.7% and 56.5%. The duration of the whole plant water content for the tested eight varieties decreased from 70% to 60% averaged 14.0 d, which 5.4 d longer than that of the cereal & silage maize varieties. The period of the whole plant water content from 70% to 60% of the tested silage maize varieties during the suitable harvest period was corresponding to 1/2-3/4 of the grain milk line position; the suitable harvest period of the special silage varieties was about 5 d longer than that of the cereal & silage varieties. the relative lower values of the grain physiological precipitation rate and the decreasing rate of the whole plant water content during the suitable silage harvest period were the main reasons for the relative longer suitable harvest periods of JKQZ516 and YY26, ZD958 and JK968.