Shamoun Simon Francis, Elliott Marianne
Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada.
Puyallup Research and Extension Center, Washington State University, 2606 West Pioneer, Puyallup, WA 98371, USA.
Pathogens. 2022 Apr 19;11(5):485. doi: 10.3390/pathogens11050485.
The invasive Oomycete pathogen has killed millions of susceptible oak and tanoak trees in California and southern Oregon forests and is responsible for losses in revenue to the nursery industry through mitigation activities. In addition, infestation of forests in the United Kingdom by this organism has resulted in the destruction of many hectares of larch plantations. Resprouting stumps can be a reservoir for the inoculum of persisting on a site. In areas where the application of herbicides is not permitted, a biocontrol treatment would be an indispensable alternative. Treatment of stumps with the sap-rotting fungus (Pers.) Pouzar has been shown to be an effective tool for the suppression of resprouting on several species, most notably red alder. In this project, the ability of to suppress resprouting was evaluated on stumps of two host species, tanoak () and California bay laurel (). Laboratory testing of three California isolates of indicated that the fungus can colonize bay laurel stems. Field trials were established near Brookings, Oregon, on tanoak and on bay laurel near Soquel, California. Early results of field testing showed that was able to colonize the stumps of tanoak following treatment and was found to occur naturally on tanoak logs and stumps. Formulations of appear to have some effect on reducing sprout survival in tanoak, but the most effective and rapid treatment for this host is the hack and squirt method of applying the herbicide imazapyr. Sprayed herbicide prevents sprouting on bay laurel, and there was evidence that resprouting was inhibited on stumps treated with . Over time, applications of may be a more permanent solution as the stumps begin to decay.
这种入侵性卵菌病原体已导致加利福尼亚州和俄勒冈州南部森林中数百万棵易感橡树和鞣皮栎树死亡，并通过减灾活动给苗圃业造成了收入损失。此外，这种生物在英国森林中的侵染已导致许多公顷落叶松人工林遭到破坏。萌生的树桩可能是该病原体在某一地点持续存在的接种体来源。在不允许使用除草剂的地区，生物防治处理将是必不可少的替代方法。用腐木真菌（Pers.）Pouzar处理树桩已被证明是抑制多种树种萌生的有效手段，最显著的是红桤木。在本项目中，评估了该真菌对两种寄主树种——鞣皮栎（）和加州月桂树（）树桩的抑萌能力。对来自加利福尼亚州的三个该真菌分离株进行的实验室测试表明，该真菌能够定殖于加州月桂树的茎干。在俄勒冈州布鲁金斯附近对鞣皮栎以及在加利福尼亚州索克尔附近对加州月桂树开展了田间试验。田间测试的早期结果表明，处理后该真菌能够定殖于鞣皮栎树桩，并且在鞣皮栎原木和树桩上自然存在。该真菌的制剂似乎对降低鞣皮栎的萌条存活率有一定效果，但对这种寄主最有效且快速的处理方法是喷施除草剂吡唑嘧磺隆的砍喷法。喷施除草剂可防止加州月桂树萌生，并且有证据表明，用该真菌处理过的树桩的萌条生长受到抑制。随着时间推移，随着树桩开始腐烂，应用该真菌可能会成为一种更持久的解决方案。
