苹果树腐烂病斑季节扩展动态

The seasonal lesion expansion dynamics of apple tree Valsa canker

本研究通过田间人工接种苹果树腐烂病病菌并在发病后对病斑进行连续观察,明确苹果树腐烂病在不同季节发生的难易程度和病斑扩展动态。结果表明,不同生长季节,苹果树腐烂病从人工接种到扩展为可见病斑（病斑径向扩展5mm）所需的时间不同,其中春季所需时间最短,平均为7.7d;其次是夏季,平均为10.2d;秋季所需时间最长,平均为12.5d。不同季节接种后形成的腐烂病斑在发病后2个月内都会出现一个快速扩展过程,随后病斑停止或缓慢扩展,经2~5个月后,再次出现一个快速扩展过程。无论哪个季节接种形成的病斑,第二个快速扩展期都出现在春季或秋季。

The purpose of this study is to make clear that the occurrence and lesion expansion dynamics of apple tree Valsa canker in different seasons by means of artificial inoculation and continuous observation in the orchard.The results showed that the time duration from artificial inoculation to a visible lesion（lesion radial expansion to5mm）were different in different seasons.The shortest time duration occurred in spring with average of 7.7 days,followed by in summer（average of 10.2 days）,and the longest one took place in autumn（average of 12.5 days）.All the lesions showed a rapid expansion process during the early stage of about 2 months after their forming no matter in which season the artificial inoculation were conducted,and then the expansion of the lesion was very slow or nearly stop,another rapid expansion process would be seen again after 2-5 months.The second rapid expansion process would appear in spring or autumn no matter in which season the artificial inoculation was made.