Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691, USA.
Phytopathology. 2010 Aug;100(8):784-97. doi: 10.1094/PHYTO-100-8-0784.
Window-pane methodology was used to determine the length and starting time of temporal windows where environmental variables were associated with annual fluctuations of Fusarium head blight (FHB) intensity in wheat. Initial analysis involved FHB intensity observations for Ohio (44 years), with additional analyses for Indiana (36 years), Kansas (28 years), and North Dakota (23 years). Selected window lengths of 10 to 280 days were evaluated, with starting times from approximate crop maturity back to the approximate time of planting. Associations were quantified with Spearman rank correlation coefficients. Significance for a given variable (for any window starting time in a collection of starting times) was declared using the Simes' multiplicity adjustment; at individual time windows, significant correlations were declared when the individual (unadjusted) P values were <0.005. In all states, moisture- or wetness-related variables (e.g., daily average relative humidity [RH] and total daily precipitation) were found to be positively correlated with FHB intensity for multiple window lengths and starting times; however, the highest correlations were primarily for shorter-length windows (especially 15 and 30 days) at similar starting times during the final 60 days of the growing season, particularly near the time of anthesis. This period encompasses spore production, dispersal, and fungal colonization of wheat spikes. There was no evidence of significant correlations between FHB and temperature-only variables for any time window; however, variables that combined aspects of moisture or wetness with temperature (e.g., duration of temperature between 15 and 30 degrees C and RH > or = 80%) were positively correlated with FHB intensity. Results confirm that the intensity of FHB in a region depends, at least in part, on environmental conditions during relatively short, critical time periods for epidemic development.
窗格法用于确定环境变量与小麦赤霉病（FHB）强度的年度波动相关的时间窗的长度和起始时间。初始分析涉及俄亥俄州（44 年）的 FHB 强度观测，此外还对印第安纳州（36 年）、堪萨斯州（28 年）和北达科他州（23 年）进行了分析。评估了 10 至 280 天的选定窗口长度，并从接近作物成熟的时间回溯到接近种植时间的起始时间。使用 Spearman 等级相关系数来量化关联。使用 Simes 的多重性调整来宣布给定变量的显著性（对于集合中任意起始时间的任意窗口）；在个别时间窗口中，当个别（未经调整）P 值 <0.005 时，宣布显著相关。在所有州，与水分或湿度相关的变量（例如，每日平均相对湿度[RH]和总日降水量）被发现与 FHB 强度呈正相关，对于多个窗口长度和起始时间；然而，最高的相关性主要是较短长度的窗口（特别是 15 和 30 天）在生长季节的最后 60 天内具有相似的起始时间，特别是在开花期附近。这一时期包括孢子产生、扩散和真菌对小麦穗的定殖。在任何时间窗口中，都没有证据表明 FHB 与仅温度变量之间存在显著相关性；然而，将水分或湿度与温度的各个方面结合起来的变量（例如，温度在 15 至 30 摄氏度之间的持续时间和 RH >或= 80%）与 FHB 强度呈正相关。结果证实，一个地区的 FHB 强度至少部分取决于流行病发展的相对较短、关键时期的环境条件。
