Preparation method and application of novel coumarin derivative plant growth regulator and composition

The invention discloses synthesis of a novel coumarin derivative plant growth regulator, a preparation method of a composition of the novel coumarin derivative plant growth regulator and application of the novel coumarin derivative plant growth regulator to kiwifruit canker resistance. The general formula of the derivative is as follows: # imgabs0 #, wherein R1 is halogen, methyl, methoxyl or disubstituted or trisubstituted of any combination of the above substituent groups, and R2 is methyl and phenyl. The derivative disclosed by the invention has a relatively good inhibition effect on kiwifruit canker, tobacco bacterial wilt, potato late blight and tobacco mosaic disease. The compound II-11 and ethylicin show a synergistic effect in the process of preventing and treating the kiwifruit canker pathogen, and the purposes of pesticide reduction and synergism can be achieved. The plant growth regulator activity of part of the compounds is tested, and the compound II-11 is found to have good auxin activity and cy