Roberts Joseph A, Ritchie David F, Kerns James P
Department of Plant Science and Landscape Architecture, University of Maryland, College Park 20742.
Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616.
Plant Dis. 2016 Mar;100(3):577-582. doi: 10.1094/PDIS-04-15-0419-RE. Epub 2016 Jan 18.
Bacterial etiolation, caused by Acidovorax avenae, is a widespread problem in creeping bentgrass putting green turf. The symptoms normally appear as abnormally elongated turfgrass stems and leaves. Observations at multiple field sites suggest the involvement of plant growth regulators (i.e., GA-biosynthesis inhibitors) commonly applied to turf, alluding to a phytohormone imbalance caused by the bacterium. A 2-year field study examined the effects of trinexapac-ethyl, flurprimidol, and paclobutrazol on bacterial etiolation severity caused by A. avenae. Trinexapac-ethyl applied at 0.05 kg a.i. ha every 7 days and 0.10 kg ha every 14 days increased etiolation compared with all other treatments in both years. Flurprimidol and paclobutrazol were not different from the control but high-rate applications caused phytotoxicity that lowered turf quality early in 2014. When the etiolated turfgrass was removed with mowing, turfgrass treated with trinexapac-ethyl exhibited the highest turfgrass quality on most rating dates. Results from this work illustrate that using plant growth regulator materials with different modes of action is a solution to managing creeping bentgrass growth while limiting the potential for bacterial etiolation outbreaks.
由燕麦嗜酸菌引起的细菌性黄化是匍匐翦股颖果岭草坪中普遍存在的问题。症状通常表现为草坪草茎和叶异常伸长。在多个田间地点的观察表明，常用于草坪的植物生长调节剂（即赤霉素生物合成抑制剂）与该病有关，这暗示了细菌导致的植物激素失衡。一项为期两年的田间研究考察了调环酸钙、氟嘧磺隆和多效唑对燕麦嗜酸菌引起的细菌性黄化严重程度的影响。在这两年中，与所有其他处理相比，每7天以0.05千克有效成分/公顷的用量施用调环酸钙以及每14天以0.10千克/公顷的用量施用调环酸钙均增加了黄化程度。氟嘧磺隆和多效唑与对照无差异，但高剂量施用在2014年初导致了植物毒性，降低了草坪质量。当通过修剪去除黄化的草坪草时，在大多数评级日期，用调环酸钙处理的草坪草表现出最高的草坪质量。这项研究的结果表明，使用具有不同作用方式的植物生长调节剂材料是在限制细菌性黄化爆发可能性的同时管理匍匐翦股颖生长的一种解决方案。
