【摘要】 通过对河南21个有烟草青枯病史的烟田和周边91个无病史的烟田调查研究表明:有病史烟田在罗山、平桥、确山、泌阳、遂平和西平6个县(区),土壤pH主要分布在5.5～6.5(占调查烟田总数的84.75%);周边无病史的烟田在唐河、正阳、上蔡、社旗、舞阳和城区6个县(区),土壤pH主要分布在6.5～7.0(占调查烟田总数的81.25%)。有病史的6个县(区)与无病史的6个县(区)在土壤pH上存在显著的差异,土壤pH6.5是河南烟草青枯病发生的阈值。土壤pH与纬度之间具有极显著的正相关性(y=0.7375x–17.799,R~2=0.386,P<0.01),由此推测土壤pH 6.5地理分界线大致在北纬33°,其以北烟区烟草青枯病发病机率低。更多还原

【Abstract】 In this paper, 21 and 91 tobacco-planting fields with and without bacterial wilt disease were surveyed and studied, the results showed that bacterial wilt disease were occurred in the tobacco-planting fields in Luoshan, Pingqiao, Queshan, Biyang and Suiping, soil pH were mainly ranged from 5.5 to 6.5(accounted for 84.75%); while no bacterial wilt disease was happenedin the tobacco-planting fields in the circumjacent regions including Tanghe, Zhengyang, Shangcai, Sheqi, Wuyang and Chenqu, soil pH were mainly ranged from 6.5 to 7.0(accounted for 81.25%). Significant difference was found in soil pH values between the two regions with and without bacterial wilt disease, and soil pH 6.5 could be regarded as the occurrence threshold of tobacco bacterial wilt disease in Henan. There was extremely significantly positive linear correlation between soil pH and latitude(y=0.7375 x-17.799,R~2=0.386,P<0.01), north latitude 33° could be regarded as the geographic boundary of soil pH 6.5, and bacterial wilt disease is less likely occur in the north of this boundary.更多还原