The invention discloses a method for preventing and treating
sclerotinia rot of colza by antagonistic
trichoderma strains, and relates to the technical field of agricultural
disease prevention and control, and the method comprises the following specific steps: S100, strain screening and
mutagenesis: separating
trichoderma strains from
rhizosphere soil of colza in different environments, primarily screening strains with antagonistic action on
sclerotinia sclerotiorum by a plate confrontation method, and carrying out
mutagenesis on the strains with antagonistic action on
sclerotinia sclerotiorum; carrying out chemical
mutagenesis treatment on the primarily screened strains, carrying out confrontation culture on the primarily screened strains and
sclerotinia sclerotiorum again, screening out high-yield antagonistic substances with larger inhibition zones and
mutant strains with strong
stress resistance, and culturing to obtain
trichoderma fermentation liquor; by obtaining the trichoderma strains which can keep efficient
antagonism and strong
stress resistance under different environmental conditions, the stability of the trichoderma strains on
disease control is enhanced, so that the rape can effectively
resist invasion of sclerotiniose under different environmental conditions in the growth process, and the
disease resistance of the rape is improved. And antagonistic active substances are extracted to prepare a biological
fertilizer carrier, and the biological
fertilizer carrier is applied to the planting process of oilseed rape, so that the growth and
reproduction of
sclerotinia sclerotiorum are effectively inhibited.