Reduction in gray mold severity in Eucalyptus benthamii seedlings treated with Trichoderma atroviride

ABSTRACT Gray mold, caused by Botrytis cinerea, is responsible for mortality of Eucalyptus benthamii seedlings. Biological control is an alternative due to the lack of products registered for eucalyptus in Brazil. This study evaluated the endophytic fungus Trichoderma atroviride, isolated from eucalypt, for controlling B. cinerea. The assay consisted in the application of a spore suspension of T. atroviride on E. benthamii seedlings at 24, 48 or 72 h before B. cinerea inoculation. Iprodione was used as positive control. Inoculated seedlings were maintained in a greenhouse for 21 days. Severity was evaluated based on a scale of symptoms from 0 (no lesions) to 4 (high severity). Trichoderma atroviride significantly reduced the disease severity, independent of the time of previous pulverization, similarly to the fungicide.

摘要：灰霉病由灰葡萄孢（Botrytis cinerea）引发，可造成本哈姆桉（Eucalyptus benthamii）幼苗死亡。鉴于巴西暂无登记在册的桉树专用防治药剂，生物防治成为可行的替代方案。本研究针对分离自桉树的内生真菌深绿木霉（Trichoderma atroviride）对灰葡萄孢的防治效果展开评估。实验方案为：在接种灰葡萄孢前24、48或72小时，将深绿木霉的孢子悬浮液喷施于本哈姆桉幼苗；以异菌脲（Iprodione）作为阳性对照。接种后的幼苗置于温室培养21天，采用0（无病斑）至4（严重发病）的症状分级量表评估病情严重程度。结果显示，无论提前喷施的时间如何，深绿木霉均可显著降低病害严重度，其防治效果与杀菌剂相当。