Selection and influencing factors of spring maize varieties suitable for mechanical harvesting in Guizhou

【Objective】In order to screen out maize varieties suitable for mechanical harvesting in Guizhou, and to clarify the status quo and main problems of mechanical granulation, provide theoretical and technical support for the promotion of mechanical harvesting technology of Guizhou spring maize.【Method】With 32 maize varieties as the research materials, random block design was adopted to carry out the selection test of maize varieties suitable for mechanical harvesting in Zunyi and Anshun, Guizhou from 2017 to 2019. Measured the kernel moisture content, broken rate, impurity rate, loss rate and yield at harvest, and used correlation analysis and two-way average mapping method to screen suitable corn varieties for machine harvesting.【Result】The average kernel moisture content, broken rate, impurity rate and loss rate of Guizhou spring maize were 30.45%, 11.71%, 1.79% and 12.58%, respectively, and the average yield was 8251.49 kg/ha, and there were differences among varieties. At present, there were some problems in the mechanical kernel harvest of spring maize in Guizhou, such as high moisture content, high broken rate and high loss rate. The correlation analysis showed that the high kernel moisture content was the main reason for the high mechanical kernel yield broken rate. By reducing the kernel moisture content at harvest time, the broken rate, impurity rate and loss rate could be reduced and the mechanical harvest yield quality could be improved. The kernel moisture content and yield were selected as the indexes. Among them, 11 varieties had low kernel moisture content and high yield, which were more suitable for mechanical harvesting. Using grain broken rate and total loss rate to screen, Xianyu 1171, Xinzhongyu 801, Xingyu 3 had the characteristics of low kernel moisture content, low broken rate, high yield and low total loss rate at harvest time, suitable for mechanical harvesting. Choosing varieties with short growth period and appropriately delaying the harvest period could effectively reduce the water content of kernels during harvest and improve the quality of mechanical harvest.【Conclusion】High kernel broken rate and high total loss rate are the main quality problems in Guizhou spring maize mechanical grain harvesting. High kernel moisture content is the main reason for poor mechanical harvest quality. Properly delaying the harvest can reduce the kernel moisture content during harvest and improve the mechanical harvest. quality. Xianyu 1171, Xinzhongyu 801 and Xingyu 3 are recommended as suitable varieties for mechanical grain harvesting of spring maize in Guizhou.