‘隆丰黑李’细菌性穿孔病病害调查及杀菌剂对其病原菌毒力测定

Investigation of Plum Bacterial Shot-hole on 'LongFeng' Black Plum and Determination Virulence of Fungicide to the Pathogen

以新品种‘隆丰黑李’闽东种植示范基地核心区为调查点,观测该病害在果园的发生区位情况,记录发病症状,分析各栽培管理措施及自然环境变化对病害发生产生的影响,并室内筛选了对该病害病原菌具抑制作用的杀菌剂。结果表明:以叶片病斑数及病斑面积占叶片面积百分比为依据划分的病情指数等级较为合理;该病在黑李园4月中下旬开始发病,平均发病率为26.04%,平均病情指数为9.62,主要危害叶片,亦可危害枝梢和果实;该病的发生与果园方位、果园管理及气侯条件存在一定的相关性,南面果园发病较重。在供测的5种杀菌剂中,6%春雷霉素和72%农用链霉素对该病病原菌的抑制效果最好,EC50分别为1.085 5 mg/mL和1.7799 mg/mL;联合毒力测定结果表明,72%农用链霉素和6%春雷霉素以6∶1和3∶1混配具增效作用,1∶1配比具相加作用,1∶3和1∶6配比具拮抗作用。

We observed the occurrences and symptoms of plum bacterial shot-hole on black plum in East Fujian Province in China, and analysized the possible impacts on this disease from the cultivation and management measures and the change of natural environment, and then efficient bactericides against this disease and their mixture ratios were screened. Our results show that, based on the number of disease spots and the ratio of disease spots area to the whole leaf area, plum bacterial shot-hole on black plum leaf could be used to classify the disease index. This disease began its occurrence in middle-later April, the average incidence and disease index was 26.04%1 and 9.62, respectively. The leaf was damaged more , and shoot and fruit were also damaged by this disease. The occurrence of this disease was associated at certain degrees with location, manage of the orchard and climate conditions. The diseases occurred in southem area of the orchard was more severe than in other locations. Our laboratory screen data revealed that 6% kasugamycin （JMAF） and 72% could efficiently inhibit this diseases, the efficiencies were on the top among five bactericides screened in our ex.periments. The EC50 of these two bactericides was 1.085 5 mg/mL and 1.779 9 mg/mL, respectively. We fatherly found that mixture ratio between 72% streptomycin and 6% kasugamycin （JMAF） showed different joint toxicity on this diseases： mixtures between ratios of 6：1 and 3：1 showed synergistic action, single ratio of 1：1 showed additive effect, while mixtures between ratios of 1：3 and 1：6 had an antagonistic effect.