The Development Of HSAF Bio-Control Agents And The Research Of The Control Effect To Pear Decay

Our pear production and pear cultivation area are in the first place of the world.Pear tree diseases is a serious threat to the development of Chinese pear industry.Pear rot disease is known as the cancer of pear industry,which affects the fruit tree growing and production. It has the characteristics of high incidences, widely occurrence and hard-control. At present, the prevention and treatment of the decay primarily depend on chemical fungicides.However, there are problems such as pollution, bad for the environment in the use of chemical fungicide.Therefore,the developpent of new bio-control agents,which has strong antimicrobial properties and be friendly to the human body and the environment, can be a benefical method of prevention and treatment, also can reduce the negative impacts of chemicals.OH11 is a novel biological control agent, which has broad antibacterial spectrum and inhibitory effect on bacteria fungi and oomycetes. Heat Stable Antifungal Factor(HSAF) is isolated from the secondary metabolites of OH 11,which has obvious inhibitory effect for a variety of bacterias, fungi and oomycetes. This experiment studied the antagonism of OH 11 to pear decay,black spot,ring spot and anthracnose.The results showed that the OH 11 bacteria has efficient antagonism effect. We extracted the fermented broth that contains HSAF.There is no obvious change before and(or) after heating. And with the increase of contents of HSAF,the inhibition effect to pear decay is gradually enhanced. Then we develop fermented broth to be water agent with 40 ug/mL HSAF and gels with 20 ug/mL HSAF.In the indoor experiment, the gels showed obvious effect of prevention and treatment in the branches and pears.In May 2013,we developped the field trials of bio-control agents in Qian county of ShanXi province,Feng county of JiangSu province and XinxiangCity of HeNan province.The results showed that HSAF daub agent,chemical armour sulfur and rootone humic acid copper are effective to, especially a sulfur rootone and HSAF daub agent.Besides,disease prevention and control effect of HSAF daub agent of scar in collateral is better than that in the trunk.The effection of HSAF water agent to pear leaves disease were higher than the local conventional drugs.HSAF water agent can inhibit the formation of new sick scar in pear tree branches.The neonatal illness spot control effect can reach 77.8% in Shaanxi area.The control effect of HSAF water agents for pear leaves diseases is equal to the local conventional drugs.