金丝小枣浆烂病发病规律研究

通过多年大量室内和田间试验与调查,研究了金丝小枣浆烂病病原菌仁果囊孢壳菌Physalospora obtuse对金丝小枣各器官和枣果的侵染、孢子萌发、越冬寄主、子实体形成规律和侵染率与降水量关系.结果表明,病原菌于6月上旬侵染枣吊、果柄,7月上旬开始侵染枣果,8月下旬为侵染高峰期,9月中旬为田间发病高峰期,前期侵染呈潜伏侵染状态.金丝小枣树皮、枣头、枣股及落果、落叶、落吊均为病原菌越冬场所,其中以落果为主.枣园周围杨树、榆树、刺槐、苹果、梨树、桃树亦为病原菌越冬寄主并传播病原菌造成危害.病原菌在越冬病枣果上可形成有性和无性繁殖体;当年病枣果形成分生孢子发生再侵染.8月中旬、下旬雨量大,是造成金丝小枣浆烂病大发生的关键因子.

Study on the IncidenceMechanism of the Thick Rotten D isease ofZ iziphus zizyphus ( L. ) Meikle. cv. 'Jinsixiaozao'

Based on a lot of laboratory experiments and field inspections,the infection of pathogens to the organs and fruits of Ziziphus zizyphus cv.'Jinsixiaozao',spore germination,overwintering host,regularity of sporocarp formation,the relation between the infecting rate and rainfall volume were studied.It was indicated that pathogens started to infect the fructiferous branches and fruit stalks in the first ten days of June.Fruits were infected in the first ten days of July,and the infecting rate reached the peak in the last ten days of August.The disease was latent infection at first.The pathogens could overwinter in many organs of Ziziphus zizyphus cv.Jinsixiaozao',such as bark,branches,leaves,and fruits.But the fruits were the most important infection source.It could overwinter in the trees of poplars,Siberian elm,peach,apple and pear around jujube garden also.The sporocarp had asexual and sexual generation on the residual diseased fruits.Sexual generation infected the jujube.The conidiophore of fresh fruits could infect again.The infecting rate of Physalospora obtuse,the pathogen,mostly depended on the rainfall precipitation in the last twenty days of August.