| In order to explore and screen out the good effect of inhibiting the growth inhibition of the mycelium of Valse mail and the mineral source with strong protective effect on the isolated branches,in order to obtain the mineral source with good effect and environment friendly,this experiment provides a certain theoretical basis for the prevention and control of apple tree rot disease in the production.Taking the apple tree rot disease as the control object and taking 7 kinds of mineral source pesticides as the test object,the study of the method of mycelium growth,conidia germination and scald inoculation on shoots in vitro were used to screen the mineral source agents,the mechanism of the drug pathogenicity,the optimization of the preparation and the preparation of the smear agent..The results obtained are as follows:1.Study on Screening and Mechanism of Mineral Source Agents for Controlling Valse mailThe preliminary screening results of 7 mineral sources by mycelium growth rate showed that among the 7 mineral sources,the rate of bacteriostasis was less than 80%,77%copper hydroxide,77%Bordeaux,77%cupric sulfate,86.2%oxygenated copper and humic acid,and 5 mineral sources,except for humic acid and humic acid.The bacteriostasis rate of the drug was higher than 80%.These 5 kinds of insecticides have relative inhibition on Apple rot.The results of colony growth showed that the 5 mineral sources of different concentrations had significant inhibitory effects on the colony growth of the pathogen,in which the inhibitory rate of sodium humate was the highest,EC50 was2.60μg/mL,followed by copper hydroxide and cuprous oxide,EC50 was 71.15 and 77.40μg/mL copper sulfate,respectively.The effect of EC50 to 95.73μg/mL Bordeaux was the worst and EC50 was 159.60μg/mL;sodium humic acid made the mycelium of the fungus thinner,distorted,deformed and even died.The results of the germination of conidia were measured by coating method.The results showed that the 5 mineral sources had significant inhibitory effect on the germination of the conidia.The inhibition effect of sodium humate on spore germination was the best,EC50 was 1.38,followed by copper hydroxide and cuprous oxide,EC50 was69.67 and 65.48ug,respectively./mL cupric sulfate is the second time,EC50 is the worst effect of 102.98μg/mL Bordeaux,EC50 is 145.41μg/mL.At the same time,with the increase of the concentration of different agents,its antibacterial activity is gradually increasing.The morphology and quantity of spores also have certain effects.The teratogenicity of sodium humate,cuprous oxide and cupric hydroxide is very strong.The effect of calcium sulfate and Bordeaux on the conidia of the pathogen is relatively weak,and there is no obvious malformation.The results of the determination of the isolated branches by scald show that the scar area of the branches treated with sodium humic acid in the 5 mineral source pesticides is the least,and the best effect for the disease is 86.83%.Therefore,humic acid sodium can be used as the best mineral source biological pesticide to control the disease.2.Optimization of coating agent preparation processThe results of experimental data analysis showed that the best auxiliary conditions for the sodium humate source preparation were optimized by response surface method,and the optimum ratio was as follows:100 mL0.5%sodium humic acid sodium solution was added to 175mg sodium alkyl sulfonate,sodium benzoate of antiseptic to 133 mg and UV protective agent to resist bad.When the blood acid was 49 mg,the rate of bacteriostasis was the largest,which was 89.75%.The results of the screening data analysis show that diatomite and organic bentonite have a great promotion effect on sodium humic acid,and sodium alginate also has a certain promotion effect,but the promotion effect is slightly lower than diatomite and organic bentonite,while sodium hydroxymethyl cellulose inhibits Valse mail.The growth has a certain inhibitory effect.But when organic bentonite and diatomite are used as carriers,there is no precipitation and no stratification when sodiu3.The quality standard of the coating agent and its evaluationThe quality control indexes of the sodium humic acid smear obtained in this paper are basically in accordance with the national regulations.The visual analysis of sodium humic smear shows that the film formation of sodium alginate has a better effect on the film forming of other carriers and is in line with the quality control of the smear agent.The composition of the smear is 5%sodium humic acid,0.25%surfactant sodium alkyl sulfonate,0.19%antiseptic sodium benzoate,0.7%UV protective agent ascorbic acid,8%sodium alginate and 6%glycerol.At the temperature of（54+2）C and-15 C,the application of the smear was not stratified after 14 d storage and no obvious change in the effect and the original solution,and the highest control effect of the sodium humate smear on the isolated branches of the apple tree infected with the pathogen was 86.90%. |
