?雖然大家普遍認為植物病菌是有害的,，但美國植物病理協(xié)會（APS）的植物病理學(xué)家認為，植物病菌可能是一種有效的控制雜草生長的工具。
??利用植物病菌來抑制雜草生產(chǎn)被認為是控制其生產(chǎn)的一種方法,，但這種方法是不適合于使用化學(xué)除草劑的區(qū)域,。美國農(nóng)業(yè)部Fort Pierce, FL.，Erin Rosskopf說：“為了阻止雜草的生長或減少除草劑對環(huán)境的影響,，除草劑的選擇或使用必須和其他方法相配合,，植物病菌也可能被使用來控制雜草的生長。”
??由于大量的雜草影響農(nóng)業(yè)的產(chǎn)量,，所以說雜草的控制是很重要的,。雜草使農(nóng)業(yè)產(chǎn)量下降了12%（引起的損失達320億美元以上），美國每年大約有2670億美元的農(nóng)業(yè)收入,。雜草也帶來了嚴重的生態(tài)學(xué)問題,。侵襲性的雜草可能會改變生態(tài)系統(tǒng)的程序，從而取代天然的植物和動物物種,。另外,，雜草也是影響農(nóng)作物的植物病菌的宿主。
??根據(jù)Rosskopf研究,，有兩種方法控制雜草生長,，一種是植物病菌---經(jīng)典的生物防治途徑，另一種是生物除草劑途徑,。經(jīng)典的生物防治途徑是運用少量的科技處理,，借助異質(zhì)病菌來控制馴化雜草。
??“正如引入昆蟲一樣,，使用引入病菌的經(jīng)典生物防治途徑?jīng)]有任何的意外和不好的影響,，有57%的全面成功。” Florida, Gainesville, FL大學(xué) Raghavan Charudattan說,。
??生物除草劑途徑是利用從雜草中分離的天然植物病菌和在感染性的繁殖體（例如孢子）上生長的天然植物病菌的一種方法,。被應(yīng)用的感染性的繁殖體會帶來高水平的感染，在經(jīng)濟效應(yīng)喪失之前,，這將大大地減少或破壞目的雜草的生長,。在生長季節(jié)期間，病菌不能普遍幸存,，就需要應(yīng)用一年生植物,。據(jù)估計,，具有潛在的生物除草劑的植物病菌有200種之多。
英文原文：
Fight Weeds With Plant Pathogens
Although plant pathogens are typically viewed as detrimental, plant pathologists with the American Phytopathological Society (APS) say plant pathogens may be a successful, eco-friendly tool for managing weeds.
"The use of plant pathogens to suppress weeds is considered as one of the alternative weed control options for areas or production systems where the use of chemical herbicides is not permitted or feasible," said Erin Rosskopf, USDA, Agricultural Research Service, Fort Pierce, FL. "Plant pathogens may also be used when the herbicide selection or usage must be rotated with other control methods in order to prevent the development of resistant weeds or lessen the impact of herbicides on the environment," she said.
Weed management is important due to the amount of damage weeds can cause to agricultural productivity. Weeds can reduce crop yields by as much as 12 percent (causing up to $32 billion in losses), based on the potential value of all U.S. crops of approximately $267 billion/year. Weeds also pose serious ecological problems. Invasive weeds are capable of altering ecosystem processes and displacing native plant and animal species. In addition, weeds serve as reservoirs for plant pathogens that impact crops.
According to Rosskopf, there are two approaches used for managing weeds with plant pathogens-the classical biological control approach and the bioherbicides approach. The classical biocontrol approach uses a pathogen imported from a foreign location to control a native or naturalized weed with minimal technological manipulations.
"Classical biological control using imported pathogens has an overall success rate of 57 percent and has been just as successful as the use of imported insects, with no instances of unexpected or undesirable effects," says Raghavan Charudattan, University of Florida, Gainesville, FL.
The bioherbicide approach utilizes native plant pathogens that are isolated from weeds and are grown to produce large numbers of infective propagules (such as spores). Infective propagules are applied at rates that will cause high levels of infection, which will greatly reduce the growth of, or kill the target weed before economic losses are incurred. Annual applications are required since the pathogen does not generally survive between growing seasons. It is estimated that there are more than 200 plant pathogens that have been or are under evaluation for their potential as bioherbicides.
More information is available in the first of a two-part series on using plant pathogens for weed biocontrol, located at www.apsnet.org/online/feature/weed1/. APS is a non-profit, professional scientific organization. The research of the organization's 5,000 worldwide members advances the understanding of the science of plant pathology and its application to plant health.
