Control Effect Of Amino-oligosaccharide On Black Scurf Of Potato

In order to decrease the chemical pesticides usage,the study about infection of Rhizoctonia solani on potatoes and indoor virulence test and field efficacy experiment have been adopted for Amino-oligosaccharide,Azoxystrobin,Thifluzamide and a mixture of Amino-oligosaccharide and Azoxystrobin concentration respectively,to screen the most effective Fungicide and provide theoretical basis for the control of black scurf.By terms of how the Rhizoctonia solani influence the growth and morbidity of potato,first of all,inoculating in the wounds has the soonest disease appears with 8days latent period and 77.77%morbidity,in comparison of inoculating in natural orifice with 9 days latent period and 66.66%morbidity.Disease appears was slower when inoculated at the cut of seed potatoes,with 19 days latent period and 49.99%morbidity.The latent period was 32.5 days and the morbidity rate was 33.33%in the method of mixing with soil.Via indoor virulence test,the compound of 3%Amino-oligosaccharide AS with250 g/L Azoxystronbin SC had the strongest inhibitory activity on growth of Rhizoctonia solani?EC=0.9217 mg/L?.The EC₅₀0 values of the four fungicides against the Rhizoctonia solani were all as follows:Amino-oligosaccharide with Azoxystronbin>Thifluzamide>Azoxystronbin>Amino-oligosaccharide.Through field trials on black scurf of potato had been taken in WeiChang county of Chengde city,Guyuan county,Kangbao city and of Zhangjia Kou city,this research revealed that the compound of 3%Amino-oligosaccharide AS with 250 g/L Azoxystronbin SC had the best prevention and control result.Method of use of the most effective control result as followed:the dosage of furrow application is 300mg/L and 2500 mg/L,while the dosage of foliar spray is 18.75 mg/L and 83.34 mg/L respectively,spray twice after 45 days of seedling emergence.The average control effect of stem canker could get to between 63.38%and 71.61%,while this number was between 77.98%and 88.02%on potato tuber,with an increase between 9.36%and 22.11%of production.Therefore,it could be suggested that the compound of biopesticide Amino-oligosaccharide and Azoxystrobin shall be recommended to control black scurf of potato,while the proportion of this compound still need to be further explored.