重茬和品种差异对豫西夏大豆“症青”现象的影响

豫西地区夏大豆发生"症青"现象可导致大豆严重减产甚至绝收,但引发这种现象的原因尚不明确,防治手段也缺乏针对性。为了有效防治豫西夏大豆"症青"现象,采用裂区试验,研究了大豆重茬和品种差异对夏大豆"症青"现象的影响。结果表明,重茬地块大豆"症青"株率平均为31.70%,正茬地块大豆"症青"株率平均为1.01%,且两者差异达极显著水平。在重茬条件下,25个大豆品种均有一定程度的"症青"现象发生,"症青"株率变幅为8.6%～58.7%,品种间差异极显著。在正茬条件下,所有大豆品种的"症青"现象均较轻,56%的品种"症青"发生率不足1%,且品种间差异不显著。由此可见,重茬导致大豆"症青"现象发生或者加重,生产上应进行合理的轮作倒茬防治大豆"症青"发生,同时选择对"症青"现象抗性较好的大豆品种。

Effect of Continuous Cropping and Varieties on "Zhengqing" Phenomenon of Summer Soybean in West Henan Province

The phenomenon of "Zhengqing" can severely reduce soybean yield.It has become a more and more serious problem for summer soybean production in the west of Henan province.However,there are only few approaches approved to be practical and efficient in solving this problem since the mechanisms of this phenomenon is still largely unknown.In this study,a split-plot experiment was conducted to investigate the impact of continuous cropping and soybean variety on the severity of "Zhengqing" of summer soybean.The results showed that the incidence of "Zhengqing" was 31.70% in continuous cropping plot,which was significant different from that of regular cropping plot with an average value 1.01%.In the case of continuous cropping,all 25 investigated varieties exhibited significantly different "Zhengqing" phenomenon to different extent,ranging from 8.6% to 58.7%.However,"Zhengqing" was less severe with no significant difference among varieties under regular croping,including less than 1% disease incidence observed in 56% of varieties.Thus,we concluded that continuous cropping could lead to the "Zhengqing" or even aggravate its severity.To prevent soybean from "Zhengqing",avoiding continuous cropping and using crop rotation instead,as well as choosing the varieties which are resistant to "Zhengqing" phenomenon were suggested.