摘要
田间试验结果表明,鸭梨叶片在生长发育期抗病性差,易感染黑星病;发育成熟后,抗病性逐渐增强。自然条件下,受叶片抗病性和孢子着落量的综合影响,鸭梨成熟叶片很少感染黑星病。鸭梨叶片从展叶到发育成熟,在梨树生长发育前期(盛花期后60d内)约需40d,后期(盛花期60d后)约需30d。正处在生长发育期的鸭梨叶片受侵染,潜育期为18~25d,发病后,病斑大,产孢期短;成熟叶片受侵染,潜育期多在40d以上,发病后,病斑小,产孢期长。梨树生长前期梨黑星病的流行主要由于大部分叶片正处在生长发育期抗病性较差;后期果实发病则主要源于成熟叶片内长期潜育和长期产孢的黑星病菌。
Field experiments with artificial inoculation showed that pear leaves were susceptible to Venturia nashicola during their growing stage and became resistant after maturation. A little infection occurred on the mature leaves in orchard because of high resistance of their leaves and few deposition conidia on them. It took 40 days for pear leaves to mature at earlier growth stages of pear trees (up to 60 days after bloom) and about 30 days at later growth stages (60 days after bloom). The latent period of the disease was 18-25 days, and disease lesions were larger and the sporula-tion period was shorter when the growing leaves were infected. The latent period of disease was longer than 40 days, and the disease lesions were smaller and the sporulation period was longer when the mature leaves were infected. The main reason of the disease epidemic in earlier season is that most of leaves are in growing stage and susceptible to pear scab. The outbreak of fruit disease during pre-picking period in some years was mostly caused by the latent scab pathogen in mature leaves, and the pathogen could persistently produced conidia.
出处
《植物保护学报》
CAS
CSCD
北大核心
2001年第4期309-312,共4页
Journal of Plant Protection
基金
国家自然科学基金(39470475)