Bradley C A, Ames K A
Department of Crop Sciences, University of Illinois, Urbana 61801.
Plant Dis. 2010 Jan;94(1):83-86. doi: 10.1094/PDIS-94-1-0083.
Quinone outside inhibitor (QoI) foliar fungicides can be effective at reducing foliar diseases in corn (Zea mays), and they have been shown to provide physiological benefits experimentally in other crops in the absence of disease. A new supplemental label for pyraclostrobin that was approved in January 2009 by the United States Environmental Protection Agency (EPA) states that corn plants applied with pyraclostrobin may have better tolerance to damage caused by hail. To determine the effects of QoI foliar fungicides on hail-damaged corn, field research trials were conducted near Champaign, IL in 2007 and 2008. Hail damage was simulated with a gasoline-powered string-mower at the V12 growth stage, which caused injury to leaves and defoliation. At VT, the foliar fungicides azoxystrobin and pyraclostrobin were applied to corn. Control treatments included a nontreated control and a nondamaged control. The simulated hail damage significantly (P ≤ 0.05) increased gray leaf spot severity (caused by Cercospora zeae-maydis) in 2007 but not in 2008. Simulated hail damage also significantly reduced yield compared with the nondamaged control in both 2007 and 2008. Foliar fungicides significantly reduced disease severity compared with the nontreated control in 2007 but not in 2008; however, foliar fungicides did not significantly improve yield in either the damaged or nondamaged plots compared with the nontreated controls. Results from our research trials indicated that foliar fungicides provided very little benefit to corn injured by simulated hail; thus, growers should consider factors other than hail damage when making fungicide application decisions for corn.
醌外抑制剂（QoI）叶面杀菌剂在减少玉米（Zea mays）叶部病害方面可能有效，并且在无病害情况下，实验表明它们对其他作物具有生理益处。美国环境保护局（EPA）于2009年1月批准的吡唑醚菌酯新补充标签指出，施用吡唑醚菌酯的玉米植株可能对冰雹造成的损害具有更好的耐受性。为了确定QoI叶面杀菌剂对受冰雹损害玉米的影响，2007年和2008年在伊利诺伊州尚佩恩附近进行了田间研究试验。在V12生长阶段用汽油驱动的割草机模拟冰雹损害，这会导致叶片受伤和落叶。在VT期，将叶面杀菌剂嘧菌酯和吡唑醚菌酯施用于玉米。对照处理包括未处理对照和未受损害对照。模拟冰雹损害在2007年显著（P≤0.05）增加了灰斑病严重程度（由玉米尾孢菌引起），但在2008年没有。与未受损害对照相比，模拟冰雹损害在2007年和2008年也显著降低了产量。与未处理对照相比，叶面杀菌剂在2007年显著降低了病害严重程度，但在2008年没有；然而，与未处理对照相比，叶面杀菌剂在受损或未受损地块均未显著提高产量。我们研究试验的结果表明，叶面杀菌剂对受模拟冰雹伤害的玉米益处甚微；因此，种植者在做出玉米杀菌剂施用决策时应考虑冰雹损害以外的其他因素。
