辽宁地区苹果炭疽病发生规律和防治研究

 在辽宁地区,苹果炭疽病菌主要以菌丝在苹果树上的小僵果、死果台、粗皮、爆皮枝等部位越冬。翌年在适宜温湿度条件下产生分生孢子,进行传播侵染。越冬后的分生孢子已失去萌发力,落地病果在初侵染中不起什么作用。
病菌可以直接穿透表皮侵入果实。苹果在幼果期即感病,此时不抗侵入但抗扩展,潜育期长达一个月左右。七月中旬以后病害大量发生,直至9月中旬持续为害。根据果园中病菌孢子出现期,约在6月15至25日喷施第一次药,以后每隔20天左右连续喷施160~200倍波尔多液或锌铜石灰液三次,可以有效地控制炭疽病的为害。1964年和1965年,在辽宁地区进行大面积防治试验表明效果良好,可以大面积推广。

ON THE PRIMARY INFECTION AND CHEMICAL CONTROL OF APPLE BITTER ROT[(GLOMERELL ACINGULATA) (STONEM.) SCHR.ET SPAULD.]IN LIAONING PROVINCE

In apple growing region of Liaoning Province,Glomerella cingulata,the causal fungus of apple bitter rot,overwintered as dormant myc-elium in small mummified fruits, dead fruiting spurs,and rough-skined t wigs on trees.Conidia that had remained on infected fruit mummies failed to germinate in the next spring.Infected fallen fruits on ground-under fruit trees played little role as source of primary infection.Und-er the climatic conditions of southern Liaoning,conidia production and dispersion started from mid-June,and young fruits were infected short-tlg after petal fall, The causal fungus penetrated into the fruits thro-ugh intact epidermis. The incubation period lasted about one month du-ring the early fruit stage.Disease incidence and development covered a period from mid-July to mid-September. Based on the results obtained from field experiments, the following spray schedule was recommerded as practicle:spraying Bordeaux Mixture (1:2:200) or Zn-Cu Lime Mixt-ure (Zn sulfate 0.5 kg,Cu sulfate 0.5 kg, Lime 2 kg,Water 200) thrice from mid-June at an intervals of about 20 days. The first spray should be performed immediately after conidia dispersion as detected with spore trapping method.