Settle D M, Fry J D, Milliken G A, Tisserat N A, Todd T C
Chicago District Golf Association, Lemont, IL 60439.
Department of Horticulture and Recreation Resources.
Plant Dis. 2007 Sep;91(9):1170-1179. doi: 10.1094/PDIS-91-9-1170.
We compared photosynthesis and multispectral radiometry (MSR) measurements with visual quality ratings for assessment of feeding injury to creeping bentgrass caused by the lance nematode (Hoplolaimus galeatus) using artificially infested microplots and a naturally infested putting green. Nematode feeding resulted in negative visual and MSR effects on creeping bentgrass in microplots. Visual quality ratings were correlated more consistently with nematode densities than either individual MSR variables or factor models of MSR variables. Threshold estimates for H. galeatus population densities associated with unacceptable bentgrass quality in microplots varied widely by month and year. Similarly, the relationship between H. galeatus population density and turf health indicators (including MSR measurements, visual ratings, and net photosynthetic rate) varied with cultivar and management practice (irrigation frequency and mowing height) in the naturally infested putting green. Notably, negative effects of nematode feeding were not consistently associated with more stressful management practices, suggesting that stress avoidance is not a reliable deterrent to H. galeatus damage in creeping bentgrass. Damage thresholds for this nematode-host association are dynamic and should be used with caution.
我们使用人工接种的小区和自然感染的果岭，将光合作用和多光谱辐射测量（MSR）与视觉质量评级进行比较，以评估由长矛线虫（Hoplolaimus galeatus）对匍匐翦股颖造成的取食伤害。线虫取食对小区内的匍匐翦股颖产生了负面的视觉和MSR影响。视觉质量评级与线虫密度的相关性比单个MSR变量或MSR变量的因子模型更一致。与小区内匍匐翦股颖质量不可接受相关的长矛线虫种群密度阈值估计因月份和年份而异。同样，在自然感染的果岭中，长矛线虫种群密度与草坪健康指标（包括MSR测量、视觉评级和净光合速率）之间的关系因品种和管理措施（灌溉频率和修剪高度）而异。值得注意的是，线虫取食的负面影响并不总是与更具胁迫性的管理措施相关，这表明避免胁迫并不是防止长矛线虫对匍匐翦股颖造成损害的可靠威慑。这种线虫-寄主关联的损害阈值是动态的，应谨慎使用。
