棉花抗枯萎病品种连作防病效果的研究

1978～1982年,在人工病圃试验调查了抗病品种连作1～5年的田间发病情况及生育产量。结果表明,抗病品种连作3年以上换种1～2年感病品种,比感病品种连作或只种1～2年抗病品种后换种感病品种,发病显著减轻,前者病害对棉花生育产量影响甚微。土壤病原菌菌量消长及土壤、病株中病原菌致病力测定,看出土壤病原菌量随抗病品种连作年限增加而减少,土壤病原菌致病力也有随抗病品种连作年限增加而减弱的趋势。抗病品种连作4年以上与只种1～2年抗病品种即改种感病品种或与感病品种连作相比,土壤病原菌量差异达极显著平准。土壤病原菌致病力差异达显著平准。

EFFECT OF SUCCESSIVELY PLANTING FUSARIUM WILT RESISTANT COTTON VARIETIES

During 1978~1982,the control effect of successively planting fusarium wilt resistant varieties was studied in an artificial inoculative bed. The results indicated that the disease caused by replanting susceptible varieties after successively planting resistant varieties for 3 or 4 years was significantly reduced.The relative disease index reduced respectively by 61.54% or 73.55% in comparison with that of the successive planting of susceptible varieties.The tests for pathogen flutuation and pathogenicity variation showed the tendency that the more years the resistant varieties were planted successively,the less was the amount of pathogens in the soil and the weaker the pathogenicity.