| Kiwifruit bacterial canker is caused by Pseudomonas syingae pv. actinidiae (Abbreviation PSA), its characteristics of occurrence is latent, propagate fastly and difficult to control, which has became a kind of devastating diseases of kiwifruit production in the world. At present, the control effects of Kiwifruit bacterial canker are poor, because the way of applying pesticide has many limitations and bactericide cannot contact with pathogenic bacteria effectively. Therefore, it is of great significance to search a effective contact way between agentia and pathogenic bacteria for the prevention and cure of kiwifruit canker. This study screened the effective pesticides from 18 kinds of pesticide products of prevention and treatment of bacterial diseases by in vitro and in vivo trials, which is aimed at exploring an effective, easy and safe trunk injection technique with pesticide for controlling kiwifruit bacterial canker.The results of the study are as follows:(1) The tube plate method was used to determine the virulence of 18 preparatory bactericides to PSA in vitro. The results show that 5 kinds of bactericide products, which were the kuizhuling, benziothiazolinone, bromothalonil, Oxytetracycline hydrochloride and ethylicin, had very obvious antibacterial effects on PSA, and all of the inhibition zones were more than 3 cm. ZhongShengmycin, streptomycin, and copper hydroxide also had antibacterial effects on PSA, with the inhibition zones between 1 and 3 cm. The other 10 pesticides had no antibacterial ability to PSA in vitro.(2) The 5 kinds of bactericide products, which were very sensitive to PSA, were chosen to determine minimal inhibitory concentration (abbreviation MIC) by the constant broth dilution method and the Turbidity method. It turned out that the concentration to inhibited the growth of bacterial colony completely of kuizhuling is lowest, MIC and EC50 values are 16.25mg/L and 3.1743mg/L respectively; benziothiazolinone is next with 40.625mg/L for MIC value and 13.9279mg/L for EC50; and the MIC values of bromothalonil, Oxytetracycline hydrochloride and ethylicin were greater than 150 mg/L, the EC50 values between 10 mg/L and 30 mg/L. Compared with 5 tested pesticide products, streptomycin bacteriostatic effects were relatively poor and the EC50 were greater than 180 mg/L.(3) Used the kiwifruit branches inoculation method to determine the treatment and protection efficacy of kuizhuling and benziothiazolinone, which both diluted 40 times, streptomycin as contrast agentia. Experimental results show that kuizhuling has the best precaution effect and treatment effect against kiwi canker, the relative control effect were 83.25% and 67.52% respectively, overtop 62.53% and 57.03% of benziothiazolinone, significantly higher than 31.07% and 17.83% of streptomycin.(4) After indoor pesticides screening, the kuizhuling was finally selected as the reagents in the field experiment to search the method of drug-delivery technique with pesticide. The results showed that using 0.3% kuizhuling water aqua with 0.075 ml/L～0.15 ml/L of effective ingredients to inject into the xylem, and dose agentia every 7d, and 3 times continuously, in December after cleaned the garden. At last, the control efficiency can reach more than 90% for kiwi canker. |
