Gross M K, Santini J B, Tikhonova I, Latin R
Department of Botany and Plant Pathology.
Department of Agronomy.
Plant Dis. 1998 Sep;82(9):1012-1016. doi: 10.1094/PDIS.1998.82.9.1012.
Controlled environment experiments were conducted to determine the influence of temperature and leaf wetness duration on infection of perennial ryegrass by Rhizoctonia solani. Infection of grass plants raised in pots and exposed to mycelium of R. solani was evaluated at various combinations of temperature and leaf wetness duration. Temperatures included 15, 18, 21, 24, and 27°C. Leaf wetness periods were 9, 12, 15, 18, and 24 h. Disease was most severe (more than 50 leaves with brown patch lesions per pot) when plants were in contact with the inoculum source for 24 h of leaf wetness at 24°C. The least amount of disease (0 leaves with lesions per pot) occurred at 15°C and a 9-h wet period. The data were subjected to analysis of variance with orthogonal polynomial contrasts. Significant effects were included in a regression model that described the response of infection to temperature and wetness duration. The polynomial model included linear and quadratic terms for temperature and wetness duration. The adjusted coefficient of determination for the fitted model was 0.93, indicating an excellent fit to the data. The model is intended for use in an improved brown patch warning system for perennial ryegrass in the midwestern United States.
进行了控制环境实验，以确定温度和叶片湿润持续时间对茄丝核菌感染多年生黑麦草的影响。在温度和叶片湿润持续时间的各种组合下，评估了种植在花盆中并接触茄丝核菌菌丝体的草株的感染情况。温度包括15、18、21、24和27°C。叶片湿润期为9、12、15、18和24小时。当植株在24°C下叶片湿润24小时与接种源接触时，病害最为严重（每盆有超过50片叶子出现褐斑病斑）。在15°C和9小时湿润期病害最少（每盆0片有病变的叶子）。对数据进行了带有正交多项式对比的方差分析。显著影响被纳入一个描述感染对温度和湿润持续时间响应的回归模型。多项式模型包括温度和湿润持续时间的线性和二次项。拟合模型的调整决定系数为0.93，表明对数据拟合良好。该模型旨在用于美国中西部多年生黑麦草改良褐斑病预警系统。
