Method for improving black shank resistance of tobacco by using seed coating

The invention provides a method for improving tobacco black shank resistance by using a seed coating, and the method specifically comprises the following steps: step 1, preparing a seed coating layer, and coating tobacco seeds; 2, observing the germination rate of the seeds; step 3, transplanting the tobacco seedlings with two leaves into a 400ml flowerpot; 4, infecting phytophthora nicotianae after transplanting for 4 weeks; 5, measuring the relative growth rate of the plants three weeks before and after infection of phytophthora; step 6, determining the diameter of a disease circle, a disease index and a control effect; the seed coating is prepared from beta-aminobutyric acid and methyl jasmonate, so that the resistance of tobacco to black shank caused by phytophthora is improved, and the resistance of tobacco to the black shank caused by phytophthora is improved by measuring indexes such as germination rate, relative growth rate, disease circle diameter, disease index and prevention and treatment effect. A