Research On The Prevention And Control Of Three Fungicides On Apple Tree Valsa Canker

Apple Tree Valsa Canker is a disease with a greater impact on apple production. The chemical control is a direct, economical and effective way to control apple tree valsa canker. In order to better guide the region’s apple production work, it is very important to find a more economical and effective way to improve the quality and yield of apples, and find a line with local apple tree valsa canker chemical control program is necessary.The test commonly chosen eight kinds of chemical control of apple tree valsa canker, through the Petri dish inhibition test, screened three kinds of effective agents; then the three kinds of agents were used in the in vitro shoots test for further study; and sub-district in the field efficacy trials conducted to obtain the following results:In the Petri dish inhibition test, the eight agents had obvious inhibiting effects on target bacteria growth, three of them had the best effect, the inhibition rate from high to low successively were 50% thiophanate methyl paste diluted 3000-fold(90.43%), 2.12% Humic acid copper agent diluted 2000-fold(87.53%) and 6.5% virus-free water agent 1000-fold(86.73%).In the vitro shoots test, in 6 days and 12 days after treatment, 50% thiophanate methyl paste diluted 3000-fold was the best agent in control the lesion. Lesion area in in 6 days and 12 days after treatment was 26.97% and 12.55% of the control.In the field experiments, after chemical treatments, the recurrence number of apple tree canker wound is very low. The recurrence rate was less than 20%, and 50% thiophanate methyl paste diluted 3000-fold has the lowest rate(7.5%), while the recurrence rate of the control was 90%. It indicated that thiophanate methyl had the best effect in control of apple cankerin field environment;...