不同时期使用农抗120控制花生网斑病侵染源的试验研究

用农抗120防治花生网斑病,不同使用方法效果不一。用常规喷洒叶面方法控制再侵染源,防效为21.4％,相当于多菌灵(29.4％);用农抗120和杀菌剂(抗枯灵或多菌灵等)混合,在花生播种时喷洒地面一次,控制初侵染源,防效为48.6％,用农抗120同杀菌剂混合,播种时喷洒地面,以控制初侵染源,7月上旬再喷洒叶面,控制再侵染源,效果最佳,防效高达70％以上。

INFLUENCE OF APPLICATION METHOD AND TIMING ON THE CONTROL EFFECT OF AGRICULTURAL ANTIBIOTIC 120 AGAINST PEANUT WEB BLOTCH (PHOMA AEACHIDICOLA) IN SHANDONG

Foliage application of fungicides in early to mid July to control secondary inoculum of Phoma. arachidicola has been the common method of contorlling peanut web blotch (PWB) in Shandong. Results of the field experiments showed that the method and timing of applying the bio-fungicide, Agricultural Antibiotic 120 (AA 120)(Streptomyces hygrospinosus var. beijingensis) were important factors influencing the control effect of the bio-fungicide against PWB. Applying AA 120 (2% water suspension diluted 200 times at 900-1,125 kg per ha.) on foliage resulted in a control effect of 21.4%, which is similar to that (29.4%) with the chemical fungicide carbendazol. Soil-surface treatment with a mixture of 2% AA 120 diluted 500 times and 40% carbendazol diluted 800 times at sowing of peanut in early May gave 48.6% control effect. The best control effect (over 70%) was obtained when two applications of the AA 120-carbendazol mature were made respectively. Soil-surface treatment in early May to control the initial inoculum of the pathogen and foliage application in -early July to control the secondary inoculum.