不同连作年限对玉米制种产量及其农艺经济性状的影响

田间试验表明,玉米制种产量及其母本农艺经济性状随连作年限的延长呈递减、降低趋势。连作3～5年的产量递减率低,达1.24%～3.50%,农艺经济性状降低不明显;连作5年以上递减幅度逐年加大,农艺经济性状降低趋势明显,其中连作7～10年的产量递减率达6.75%～9.36%。导致减产的主要原因是连作年限延长影响玉米的生长发育,降低了穗粒数和千粒重。生产上制种玉米连作5年以下是可行的,长期连作必须加强地力培肥和土壤消毒灭菌。

Effect of Continuous Cropping on Yield and Agronomic and Economic Traits of Corn Seed Production

Effect of continuous cropping on yield and agronomic and economic traits of corn seed production was investigated in the field. The results showed that the yield and agronomic and economic traits of corn seed produc-tion had a descending trend with the years of continuous cropping of corn. The yield declining rate reached 1.24% ～ 3.50% and its agronomic and economic traits did not obviously decreased for three to five years. The declining amplitude was aggravated and agronomic and economic traits decreased significantly for five years or more, which yield decline rate reached 6.75 ～ 9.36% for continuous cropping seven to ten years. The main reason for the yield declining was the prolonging of continuous cropping because it influenced the growth and development of corn and decreased the grains number per spike and 1000 -grain weight. Therefore, continuous cropping less than five years was feasible in actual production. The techniques for long continuous cropping of corn seed production were prac-tised, which include soil fertility improvement and soil disinfection and sterilization.