The Synergistic Complex Research Of Pyrazole Kresoxim And Polyxin To Prevent Tomato Late Blight

Tomato late blight is an important disease on tomato production, with the change of agricultural planting structure, greenhouse tomato acreage is growing, the greenhouse is very suitable late blight outbreaks for low temperature and high humidity conditions in the winter and spring, as well as poor farmers’ management, drug resistance, tomato price fluctuations and other factors, late blight is getting worse. In this study, the growth rate method of pyrazole Kresoxim mixed with different combinations of polymyxin for Phytophthora infestans in vitro tests, to explore their scientific and reasonable proportion, Then, the tomato safety testing and field efficacy trials, by spraying 40% pyrazole Kresoxim · polymyxin SC,evaluat their safety on the tested tomato varieties and tomato late blight control effect in the field. The results are as follows:1, The vitro tests showed that: pyrazole Kresoxim original drug, Polyoxin original drug and two different drug combinations mixed in different concentrations, the bacteria colony growth rate differences are significant, tomato late blight bacteria showed good inhibitory activity, The EC50 values of pyrazole Kresoxim original drug and Polyoxin original drug are 0.51μg/mL, 20.98μg/mL respectively. In the 5 different mixed combinations pyrazole Kresoxim and polymyxin, pyrazole Kresoxim : polymyxin=23:17, EC50 value of the minimum for 0.48μg/mL, efficiency factor SR = 1.95, increasing effect significant role.2, Based on the choice of vitro tests 23% pyrazole Kresoxim : 17% polymyxin mixed portfolio preparation process. To finalize formulation pyrazole Kresoxim 23%, 17% polyoxin, 2% wetting agent P, 3% EO-PO block copolymer,0.4% Silicone 1522, propylene glycol 5%, 1% xanthan gum, 1% magnesium aluminum silicate, the water make up 100%. After testing 40% pyrazole Kresoxim · Polyoxin SC performance indicators qualified.3, In the field trials, the test agent of 40% pyrazole Kresoxim · Polyoxin SC tested growth safe, without adverse effects to the tomato varieties. The test chemicals of 40%pyrazole Kresoxim · Polyoxin SC of tomato late blight have better control effect, The control effect differences of the 2000 times, 3000 times, 4000 times were highly significant level,after the last drug treatment 7d, 14 d. Baoji testing ground, after the last drug 7d control effect of about 66% ~ 81%, after the last drug 14 d control effect of about 63% ~ 79%; Yangling testing ground, after the last drug 7d control effect of about 70% ~ 85%, after the last drug 14 d control effect of about 65% to 81%.4, The studies show that: 40% pyrazole Kresoxim · polyoxin SC suitable dilution is 3000 times to 2000 times(active ingredient dosage 133.3 mg/kg to 200 mg/kg), foreseen in the pathogenesis of tomato late blight or the early onset of spraying every 7 to 10 days interval spraying once, even spraying 2 to 3 times. Combined agricultural control measures as well as with other fungicides variety of different mechanisms used interchangeably, to raise awareness of tomato late blight control.