Halley S, Bradley C A, Lukach J R, McMullen M, Knodel J J, Endres G J, Gregoire T
Langdon Research Extension Center.
Department of Plant Pathology, North Dakota State University, Fargo 58105.
Plant Dis. 2004 Oct;88(10):1123-1126. doi: 10.1094/PDIS.2004.88.10.1123.
Pasmo, caused by Septoria linicola, reduces flax (Linum usitatissimum) yield in the Canadian provinces of Manitoba and Saskatchewan, but little is known about its distribution and effect on yield in North Dakota. Field surveys for pasmo were conducted in 74 and 87 flax fields across 19 and 23 North Dakota counties in 2002 and 2003, respectively. The surveys indicated that pasmo was present in 17 and 18 counties in 2002 and 2003, respectively. County mean plant incidences ranged from 0 to 21% and 0 to 84.5% in 2002 and 2003, respectively. County mean pasmo severity ranged from 0 to 38.8% and 0 to 29.3% in 2002 and 2003, respectively. Significant (P ≤ 0.07) positive Pearson correlations were detected between total rainfall accumulated for June to August and pasmo severity in 2002 and 2003 and for rainfall and pasmo incidence in 2003. Field trials were conducted to determine the effect of fungicides and flax cultivars on pasmo severity and flax yield. Pasmo severity was significantly (P ≤ 0.05) reduced with azoxystrobin and sulfur fungicides compared with the untreated control. Flax yields were significantly (P ≤ 0.05) greater in azoxystrobin- and prothioconazole-treated plots than in the untreated control plots. Cv. Omega had significantly lower pasmo severity than the other three cultivars, but cv. Rahab 94 had the greatest yield of all the cultivars. Based on the results presented, pasmo is an important disease of flax in North Dakota, and its distribution is widespread throughout the flax-production region. Fungicides such as azoxystrobin and prothioconazole appear to be excellent potential tools for pasmo management.
由亚麻叶点霉引起的亚麻叶斑病会降低加拿大曼尼托巴省和萨斯喀彻温省的亚麻（亚麻）产量，但对于其在北达科他州的分布及对产量的影响却知之甚少。2002年和2003年分别在北达科他州19个和23个县的74个和87个亚麻田进行了亚麻叶斑病田间调查。调查表明，2002年和2003年分别有17个和18个县出现了亚麻叶斑病。2002年和2003年各县的平均发病植株率分别为0%至21%和0%至84.5%。2002年和2003年各县的平均亚麻叶斑病严重程度分别为0%至38.8%和0%至29.3%。在2002年和2003年，检测到6月至8月累计总降雨量与亚麻叶斑病严重程度之间存在显著（P≤0.07）的正皮尔逊相关性，在2003年降雨量与亚麻叶斑病发病率之间也存在显著相关性。进行了田间试验以确定杀菌剂和亚麻品种对亚麻叶斑病严重程度和亚麻产量的影响。与未处理对照相比，嘧菌酯和硫磺杀菌剂显著（P≤0.05）降低了亚麻叶斑病严重程度。嘧菌酯和丙硫菌唑处理的地块的亚麻产量显著（P≤0.05）高于未处理对照地块。Omega品种的亚麻叶斑病严重程度显著低于其他三个品种，但Rahab 94品种的产量在所有品种中最高。根据所呈现的结果，亚麻叶斑病是北达科他州亚麻的一种重要病害，其分布在整个亚麻生产区域广泛存在。嘧菌酯和丙硫菌唑等杀菌剂似乎是防治亚麻叶斑病的极佳潜在工具。
