Popularizing Of Integrated Control Technology To Larch Blight

Larch blight {Botryosphaeria laricina(Sawada)Shang) is the major disease in larch artificial forest in northern China. The disease is the host dominating disease that the control must be started from the adjustment of of forest ecological relation by integrated control measure based on planting and fostering in order to enhance the hosts resistance.The research was on the influence factors of the larch blight in artificial forest of Tongtianyi forestry center of Boli county, Heilongjiang province. The results show that the necessary conditions to larch blight occurrence are the temperature difference between the maximum and the minimum is equal to or greater than 12C, the maximum of the day wind power is equal to or greater than 4m/s in May to June, and in addition the function of rainfall in June and July; The disease resistance between the larch species is related with larch phonological period. The time to grow new branch for easy infected kinds is beforehand 7-15 days and that for resistance kinds is later 15 days or so. The water content of new tip directly influence the lignification level, and shows positive relevance. Inorganic factors K+ Mn++ catechinic acid etc in the newborn branch have inhibiting and killing effects to pathogen establish and expension.The results of pharmacon screening indoor and outdoor show that Senbao No. 1, mixture of Senbao No. 1 and carbendazim have effective control to larch blight, the control effects are up to 65%.Integrated control measures including selection of tree kinds, planting right trees in right fields, forestry planting and fostering, chemical control and so on were used at Tongtianyi forestry center of Boli county and Hongqi forestry center of Dongjingcheng forest bureau of Heilongjiang, and the good effects were got. The average control efficiency is up to 65%, the ratio of investment and production about 1:16. The disease index of middle-young forestry was be controlled below 20 and that of the young forestry below 10. So the disease is under control basically.