Soil nutrient elements affecting the occurrence of tobacco bacterial wilt in Qingjiang River Basin

ObjectiveThe study was conducted to survey the soil nutrients that affected occurrence of tobacco bacte-rial wilt in Qingjiang River Basin,and provide theoretical basis for the rational prevention and control of tobacco bacterial wilt in the area.MethodThe soil samples from two kinds of fields(bacterial wilt field and non-bacterial wilt field)were collected during full outbreak period of tobacco bacterial wilt(97 d after transplanting)in Xuan'en,Enshi,Hubei Province in 2016.The contents of nutrition elements in rhizosphere soil were determined,then the relationship between incidence of tobacco bacterial wilt disease,disease index and nutrient elements in rhizosphere soil was researched using a variety of statistical analysis methods.Resultt test showed that,among the 16 soil nutrient elements indexes,10 indexes presen-ted significant difference(P<0.05)or extremely significant difference(P<0.01)in two kinds of fields.The results of canoni-cal correlation analysis indicated that increasing of pH and contents of cation exchange capacity,exchangeable calcium content,and reducing the contents of soil organic matter,organic nitrogen,organic carbon,effective iron could reduce the morbidity and disease index of tobacco bacterial wilt within certain extent.Group analysis revealed that the appropria-te soil nutrient condition for inhibiting the disease were pH at 5.0-7.0;the organic matter content 1.5%-2.5%,the contents of cation exchange capacity,exchangeable calcium and calcium/magnesium ratio were higher than 20.0 cmol/kg,1000 mg/kg and 15 respectively,and contents of organic nitrogen,organic carbon and effective iron lower than 0.15%,1.0% and 50 mg/kg respectively.ConclusionThe occurrence of tobacco bacterial wilt is closely bound up with soil nutrients in Qingjiang River Basin.