烟后轮作玉米的适宜种植密度研究

Selection of Suitable Cultivation Density of Maize after Tobacco Rotation

为了明确烟后轮作不同品种玉米的适宜种植密度,2020年在湖南省浏阳市达浒镇金田村以湘农甜玉3号和郑单958为材料,设置5个密度水平,其中湘农甜玉3号的种植密度分别为42 000(T1)、48 000(T2)、54 000(T3)、60 000(T4)、66 000(T5)株/hm^(2),郑单958的种植密度分别为45 000(S1)、52 500(S2)、60 000(S3)、67 500(S4)、75 000(S5)株/hm^(2),比较分析不同密度处理下不同品种玉米的生长发育情况和产量。结果表明:不同密度处理下,2种玉米的生育期没有显著差异;从吐丝期起,2种玉米的叶面积指数和干物质积累量均随密度增加而增加;过高的轮作密度导致湘农甜玉3号倒伏倒折率增加、秃顶变长,郑单958的总叶片数和空秆率增加、穗粒数降低;2种玉米的产量均随着密度的增加先增加后下降,湘农甜玉3号以T3处理的产量最高,郑单958则以S3处理产量最高。该地区烤烟收获后轮作甜玉米和普通玉米的最佳密度分别为54 000株/hm^(2)和60 000株/hm^(2)。

In order to study the optimal planting density of maize in post-tobacco rotation, Xiangnong Tianyu No.3 and Zhengdan 958 were used as materials in Jintian Village, Dahu Town, Liuyang City, Hunan Province in 2020.The planting densities of Xiangnong Tianyu No.3 were 42 000(T1),48 000(T2),54 000(T3),60 000(T4)and 66 000(T5)plants/hm^(2),respectively, while which of Zhengdan958 was 45 000(S1),52 500(S2),60 000(S3),67 500(S4),75 000(S5)plants/hm^(2).The growth and development and yield of different maize varieties under different density treatments were compared and analyzed.The results showed that there was no significant difference in the growth period of the two kinds of maize under different density treatments, but the leaf area index and dry matter accumulation of the two kinds of maize increased with the increase of density from the silking stage.Excessive rotation density led to the increase of lodging rate and bald top length of Xiangnong Tianyu No.3,resulting in the increase of total leaf number, empty culm rate and spike grain number of Zhengdan 958.The yield of two kinds of maize increased at first and then decreased with the increase of density.The yield of Xiangnong Tianyu No.3 was the highest in the T3 treatment, while that in Zhengdan 958 was the highest in the S3 treatment.This means that the optimum density of sweet corn and common corn in flue-cured tobacco rotation after harvest was 54 000 plants/hm^(2)and 60 000 plants/hm^(2),respectively.