环境因子及栽培措施对核桃细菌性黑斑病的影响

Influence of Environmental Factors and Cultivation Measures on Bacterial Black Spots in Walnuts

为找出核桃黑斑病的发生与核桃品种、生长环境以及栽培措施之间的关系,调查了17个核桃品种的病情指数,生长地的海拔、地形坡度、降雨量、温度、郁闭度、地面覆盖率等环境因子,以及灌溉次数、防治次数、是否清园等栽培措施,采用主成分分析法和相关性方法分析了环境因子、栽培措施与核桃细菌性黑斑病发生的关系。结果表明:(1)根据17个核桃品种的病情指数得出中强特勒、辽核1号、西扶为抗病品种;(2)发现核桃黑斑病病情指数与郁闭度、防治次数和是否清园具有强相关性,郁闭度为正相关,防治次数和是否清园为负相关,平均温度、地面覆盖率与病情指数为负相关。(3)核桃黑斑病发病率与雨水为极显著正相关,与海拔高度为极显著负相关。建议在推广中应结合立地条件,合理布局,两树的间距需在6 m以上,郁闭度控制在0.6以下,并做好清园、灌溉和防治等树体管理工作,以减少核桃病害的发生。

In order to identify the relationship between the occurrence of black spot disease in walnuts and walnut varieties,growing environment,and cultivation measures,the disease index of 17 walnut varieties,environmental factors such as habitat elevation,topographic slope,rainfall,temperature,canopy density,and ground coverage rate,as well as cultivation measures including irrigation frequency,prevention and control frequency,and the necessity of clearing the orchard were investigated.Principal component analysis and correlation method were used to analyze the relationship between environmental factors,cultivation measures,and the occurrence of bacterial black spots in walnuts.The results show that:(1) according to the disease index of 17 walnut varieties,Zhongqiangtele,Liaohe 1,and Xifu are disease-resistant varieties;(2) the disease index of black spots in walnuts has a strong correlation with canopy density,prevention and control frequency,and necessity of clearing the orchard;it is positively correlated with canopy density and negatively correlated with the prevention and control frequency and necessity of clearing the orchard;in addition,it is negatively correlated with average temperature,ground coverage rate,and disease index;(3) the incidence rate of black spot disease in walnuts is significantly positively correlated with rainfall and negatively correlated with elevation.It is suggested that the habitat conditions should be considered during the promotion,and a reasonable layout that the distance between the two trees should be more than 6 m,and the canopy density should be controlled below 0.6,is favorable.Tree management work such as orchard clearing,irrigation,and prevention and control should be done to reduce the occurrence of walnut diseases.