Regulation of several plant growth substances on pine shoot growth and their effects on shoot pests controlling.

The CEPA,GA3,PP333 and B9 were sprayed on the shoot needles of Pinus massoniana,P.thunbergii,P.elliottii and P.taeda with different concentrations in order to observe their effects on pine shoots growth.The results showed that GA3(2 500 mg·L-1) promoted the shoots length of all species significantly(except to P.elliottii.in Experiment 3).In contrast,the shoots length of P.massoniana,P.elliottii and P.thunbergii were restrained significantly by PP333(5 000 mg·L-1),and the shoots length of P.elliottii and P.taeda were restrained significantly by the complex preparation of 5 000 mg·L-1 PP333 and 5 000 mg·L-1 B9(1∶1),in different experiments.And they were the best growth substances for each specie.The tropism responses of Dioryctria rubella to the volatiles of pine shoots were investigated with "Y"-tube olfactometer,the results were obvious compared with CK.The field survey showed the damage rate of the treated pine shoots were lower than that of control obviously.