Del Río L E, Venette J R, Lamey H A
Department of Plant Pathology, North Dakota State University, Fargo 58105.
Plant Dis. 2004 Dec;88(12):1352-1356. doi: 10.1094/PDIS.2004.88.12.1352.
Studies on chemical control of white mold, conducted between 1994 and 2001 at several locations in North Dakota, resulted in diverse levels of white mold incidence and severity. Navy bean cultivars were evaluated in on-farm trials between 1994 and 1996, while pinto bean cultivars were used between 1997 and 2001. The relationship between yield and white mold incidence in these trials was examined using correlation and regression analysis. White mold incidence was correlated to severity using a second-degree polynomial equation (R = 0.90, P = 0.0001) in pinto bean experiments. For every percent unit increase in white mold incidence, yield was reduced by 12 kg/ha (range 7 to 19 kg/ha) in pinto bean and by 23 kg/ha (range 19 to 26 kg/ha) in navy bean. In both instances, the coefficients of determination were significant (P < 0.04) for most locations or years, and ranged from 0.42 to 0.87 for pinto bean and from 0.98 to 0.99 for navy bean. Fungicide-protected plots had an average white mold incidence of 34 and 50% compared with 76 and 73% in nonprotected plots for pinto and navy bean, respectively. Fungicide applications increased yields by 33 and 26% (P ≤ 0.05) for pinto and navy bean, respectively.
1994年至2001年期间，在北达科他州的多个地点开展了关于白霉病化学防治的研究，结果显示白霉病的发病率和严重程度各不相同。1994年至1996年期间，在农场试验中对白芸豆品种进行了评估，而1997年至2001年期间使用的是斑豆品种。在这些试验中，使用相关性和回归分析研究了产量与白霉病发病率之间的关系。在斑豆试验中，使用二次多项式方程（R = 0.90，P = 0.0001）将白霉病发病率与严重程度相关联。斑豆中，白霉病发病率每增加1个百分点，产量降低12公斤/公顷（范围为7至19公斤/公顷）；白芸豆中，产量降低23公斤/公顷（范围为19至26公斤/公顷）。在这两种情况下，大多数地点或年份的决定系数均具有显著性（P < 0.04），斑豆的决定系数范围为0.42至0.87，白芸豆的决定系数范围为0.98至0.99。使用杀菌剂处理的地块，斑豆和白芸豆的白霉病平均发病率分别为34%和50%，而未处理地块的发病率分别为76%和73%。施用杀菌剂后，斑豆和白芸豆的产量分别提高了33%和26%（P ≤ 0.05）。
