In forest regeneration areas, alongside roads and railways, under electric power lines and above gas pipe lines, there is a need for regular sprout control. A biocontrol method against broadleaved sprouting with formulations including the decay fungus Chondrostereum purpureum (Pers. Ex Fr.) Pouzar has been shown to be effective. Yet, heavy rain during spreading of this fungal inoculum on freshly cut stumps may affect the efficacy of the treatment, i.e., stump mortality during the following years. Thus, we performed an experiment where freshly cut birch stump surfaces (Betula pendula Roth and Betula pubescens Ehrh.) were treated with fungal inoculum under heavy irrigation and without it. Furthermore, two different adjuvants which aimed to fix the fungal inoculum to freshly cut stumps during irrigation and to protect against solar radiation were tested. Our results revealed that the artificial rainstorm treatment caused a delay in the efficacy of C. purpureum, but after three growing seasons, there was no significant difference in the mortality of birch stumps treated under irrigation or without it (stump mortalities 74 and 86%, respectively). Adjuvants did not improve the efficacy in stumps treated under irrigation nor in those treated without irrigation. KEY POINTS: • Heavy rain delayed the sprout control efficacy of a fungus Chondrostereum purpureum. • Final efficacy of formulations was the same in wet and dry conditions. • No additional adjuvants are needed to improve formulations.

中文翻译：

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暴风雨对北方森林中腐烂真菌紫草对白桦发芽的生物防治功效的影响。

在森林再生区，在公路和铁路旁，在电力线之下和在煤气管道之上，需要定期进行萌芽控制。已经证明了用包括腐烂真菌Chondrostereum purpureum（Pers。Ex Fr.）Pouzar在内的制剂对抗阔叶发芽的生物防治方法是有效的。然而，这种真菌接种物在刚切下的树桩上散布期间的大雨可能会影响治疗效果，即随后几年树桩的死亡率。因此，我们进行了一项实验，在真菌灌溉液的作用下，对新鲜切开的桦树树桩表面（白桦（Betula pendula Roth）和白桦（Betula pubescens Ehrh。））进行处理，而无真菌接种。此外，测试了两种不同的佐剂，其目的是在灌溉过程中将真菌接种物固定在刚切下的树桩上并防止日光辐射。我们的结果表明，人工暴雨处理导致紫pur的功效延迟，但是在三个生长季节后，在灌溉或不灌溉的情况下，桦树桩的死亡率没有显着差异（树桩死亡率分别为74％和86％，分别）。佐剂不能改善经灌溉或未经灌溉的残端的功效。要点：•大雨延缓了紫草软骨菌的发芽控制功效。•制剂的最终功效在干湿条件下均相同。•无需其他佐剂即可改善配方。我们的结果表明，人工暴雨处理导致紫pur的功效延迟，但是经过三个生长季节后，在灌溉或不灌溉的情况下，桦树桩的死亡率没有显着差异（树桩死亡率分别为74％和86％，分别）。佐剂不能改善经灌溉或未经灌溉的残端的功效。要点：•大雨延缓了紫草软骨菌的发芽控制功效。•制剂的最终功效在干湿条件下均相同。•无需其他佐剂即可改善配方。我们的结果表明，人工暴雨处理导致紫pur的功效延迟，但是经过三个生长季节后，在灌溉或不灌溉的情况下，桦树桩的死亡率没有显着差异（树桩死亡率分别为74％和86％，分别）。佐剂不能改善经灌溉或未经灌溉的残端的功效。要点：•大雨延缓了紫草软骨菌的发芽控制功效。•制剂的最终功效在干湿条件下均相同。•无需其他佐剂即可改善配方。在灌溉条件下或未灌溉条件下，桦树桩的死亡率没有显着差异（树桩死亡率分别为74％和86％）。佐剂不能改善经灌溉或未经灌溉的残端的功效。要点：•大雨延缓了紫草软骨菌的发芽控制功效。•制剂的最终功效在干湿条件下均相同。•无需其他佐剂即可改善配方。在灌溉条件下或未灌溉条件下，桦树桩的死亡率没有显着差异（树桩死亡率分别为74％和86％）。佐剂不能改善经灌溉或未经灌溉的残端的功效。要点：•大雨延缓了紫草软骨菌的发芽控制功效。•制剂的最终功效在干湿条件下均相同。•无需其他佐剂即可改善配方。