Investigation of Kiwifruit Bacterial Canker Disease(Pseudomonas syringae pv.Actinidiae Takikawa) in Guanzhong Area of Shanxi Province and Its Biological Control

[ Objective ] The paper was to grasp the incidence characteristic of kiwifruit bacterial canker disease （Pseudomonas syrirtgate pv. actinidiae Takikawa） in Guanzhong area of Shanxi province, and to screen the endophytic actinomycetes with control effect against kiwifruit bacterial canker. [ Method] The incidence characteristics of kiwifruit bacterial canker disease in 65 orchards of 13 villages in guanzhong area of Shanxi province （Yangling, Zhouzhi, Meixian） were investiga- ted and analyzed. The antagonistic strains against Pseudomonas syringae were simultaneously screened from 242 endophytic actinomycetes, and carried out field dis- ease control test. [ Result] The average incidence rate of kiwifruit bacterial canker disease in guan^ong area of Shanxi province was 7.95% ; the variety of kiwifruit had dose relationship with incidence rate. 76 strains bad inhibition activity agmnst P. syringae, while the inhibition zone diameters of fermentation broths of 35 strains against P. syr/ngae were greater than 20 nun. TIASA5 strain had inhibition activity against four target bacteria; gCLA4 strain not only had inhibition activity against four target bacteria, but also had strong inhibition activity against 10 species of plant pathogenic fungi. Field test showed that the fermentation broth of gCLA4 strain had obvious control effect against kiwifruit bacterial canker disease, and the relative control effect at 21 d could reach 66.7%. [ Conclusion] The an- tibacterial spectrum of fermentation broth of gCLA4 strain is broad, so gCLA4 strain has the potential to be developed into a broad-spectrum agricultural fungicide. Key words Kiwifruit bacterial canker disease; Endophytic actinomycetes; Biological control; Field test

Factors Influencing Bacterial Canker Disease of Kiwifruit and the Control Countermeasures

Survey was conducted to investigate the occurrence laws of bacterial canker disease of kiwifruits in Liupanshui area, Guizhou Province, and the patho- gens and hazard symptoms of the canker disease were introduced. The results showed that the factors influencing the occurrence of bacterial canker disease of ki- wifruit were identified as inter-species resistance, agronomic traits, meteorological and ecological conditions, cultivation and management techniques and fertilization levels. Techniques for the comprehensive control of kiwi canker disease were stated, and control suggestions were proposed.