Biological Fumigation Of Broccoli Residues To Major Soil-borne Diseases Of Potato

Potato(Solanum tuberosum L.)is an annual plant in the Solanum family with edible tubers and is the fourth most important food crop in the world.With the development of potato industry,potato planting area has been gradually expanded,and the long-term continuous cropping mode has led to the increase of soil-borne potato diseases year by year.Soil-borne diseases not only affect potato quality,but also pose serious threat to potato yield.Biological fumigation is a natural,environmentally friendly and promising prevention and control measure.It is expected to be a substitute for chemical fumigation in the future.In this study,the biological fumigation of broccoli was used as the experimental material to explore the effects of biological fumigation on the main soil-borne disease pathogens and beneficial microorganisms of potato,the occurrence of soil-borne disease and the growth of potato.At the same time,beneficial rhizosphere microorganisms adapted to the fumigation of broccoli residues were screened to provide a new idea for the further prevention and control of soil-borne potato diseases by using this technology.The main research results are as follows:1.The indoor fumigation test showed that different varieties of broccoli residues had certain inhibitory effects on mycelial growth,spore quantity,spore germination and mycelial dry weight of pathogenic fungi,such as Pterocarpaceae,Pterocarpaceae,Molevia nevi and Fusarium oxysporum,among which the biological fumigation effect of varieties Zhongqing12 and emeralds was the best.Broccoli residue had a certain inhibitory effect on the number of black tibia colonies,and the inhibitory rate on scab bacteria could reach 100% after fumigation for 3 days.2.Different broccoli varieties have different biological fumigation effects on beneficial microorganisms.The different varieties of emeralds broccoli,bisheng and zhonghua luxiu had little inhibitory effect or promoting effect on biocontrol fungi,and there were some differences in fumigation effect on different biocontrol bacteria.Among the biocontrol fungi tested,Tricheoderma PT-29 was the least affected by biological fumigation of broccoli residues.3.The indoor pot experiment showed that soil fumigation with broccoli residues could promote the growth and dry matter accumulation of potato plants,reduce the incidence and disease index of potato nevus,blight and Verticillium wilt,and had significant effects on promoting growth and controlling disease.4.Isolation of potato rhizosphere microorganisms after biological fumigation of broccoli residues was carried out.The results showed that 3 strains of Bacillus were screened out from the 367 strains that had good inhibitory effect on potato nevus,Fusarium wilt and Verticillium wilt,among which the strains WCT-G-3 and NCT-G-9were identified as Bacillus cereus.JNT-G-9 is Bacillus thuringiensis.These beneficial microorganisms in the potato rhizosphere laid a foundation for the subsequent combined fumigation of broccoli to prevent and control soil-borne potato diseases.