Department of Plant Biology and Biotechnology, University of Copenhagen, Frederiksberg C, Denmark.
Phytopathology. 2011 Feb;101(2):231-40. doi: 10.1094/PHYTO-04-10-0113.
Sheath blight caused by Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) is a major cause of crop loss in intensive rice production systems. No economically viable control methods have been developed. We screened aqueous extracts of common herbal plants that could reduce sheath blight lesions and found that foliar spraying and seed soaking application of extracts of either fresh or dried leaves of Chromolaena odorata gave up to 68% reduction in sheath blight lesion lengths under controlled and semi-field conditions. The observed reductions were not dependent on growth conditions of C. odorata and rice cultivar. The effect was observed until 21 days after inoculation and was not dependent on microbial activity. Under semi-field conditions, extracts also reduced severity of other important rice diseases, i.e., blast (Pyricularia oryzae) using foliar spray (up to 45%), brown spot (Bipolaris oryzae) using seed treatment (up to 57%), and bacterial blight (Xanthomonas oryzae pv. oryzae) using both application methods (up to 50%).
由立枯丝核菌（同物异名：尖孢镰刀菌）引起的鞘腐病是集约化水稻生产系统中作物减产的主要原因。目前尚未开发出经济可行的控制方法。我们筛选了常见草药的水提物，这些水提物可以减少鞘腐病斑，发现无论是新鲜的还是干燥的黄菊属植物叶子的叶喷和浸种应用，在控制和半田间条件下，可使鞘腐病斑长度减少高达 68%。观察到的减少与黄菊属植物和水稻品种的生长条件无关。这种效果可观察到接种后 21 天，并且与微生物活性无关。在半田间条件下，提取物还通过叶喷（高达 45%）减少了其他重要稻病的严重程度，如稻瘟病（Pyricularia oryzae），通过浸种处理（高达 57%）减少了褐斑病（Bipolaris oryzae），通过两种应用方法（高达 50%）减少了细菌性条斑病（Xanthomonas oryzae pv. oryzae）。
