Kirk W W, Felcher K J, Douches D S, Coombs J, Stein J M, Baker K M, Hammerschmidt R
Department of Plant Pathology.
Department of Crop and Soil Sciences.
Plant Dis. 2001 Oct;85(10):1113-1118. doi: 10.1094/PDIS.2001.85.10.1113.
Field experiments were conducted during 1998 to 2000 to determine the response of commercial potato cultivars and advanced breeding lines (ABL) differing in susceptibility to foliar late blight (caused by Phytophthora infestans) to reduced rates and frequencies of residual, contact fungicide applications. When environmental conditions were most favorable for the development of late blight, the lowest application rate of the fungicides chlorothalonil or fluazinam (33% of the manufacturers' recommended application rate [MRAR]) gave unsatisfactory control of potato late blight. Under conditions moderately conducive for late blight development, effective control was achieved with 33 to 66% MRAR with either fungicide. The Michigan State University advanced selection, MSG274-3, was the least susceptible ABL tested and, during 1998 to 2000, late blight was effectively managed using reduced rates of fungicides. Application rates of chlorothalonil (33 to 100% MRAR) significantly reduced late blight in the cultivar Snowden (5-day application interval) compared with the nontreated control; whereas, late blight was not effectively controlled in Snowden even at 100% MRAR of chlorothalonil at either 10- or 15-day application intervals in 1999 or 2000. The ABL MSG274-3 was the least susceptible of all cultivars and ABL used in this study, and required minimal chemical protection against late blight. The study demonstrates that ABL with reduced susceptibility to late blight can be managed with reduced fungicide rates and longer application intervals, thus offering more economical control of this disease.
1998年至2000年进行了田间试验，以确定对叶部晚疫病（由致病疫霉引起）易感性不同的商用马铃薯品种和高级育种系（ABL）对残留接触型杀菌剂施用量减少和施用频率降低的反应。当环境条件最有利于晚疫病发生时，杀菌剂百菌清或氟啶胺的最低施用量（制造商推荐施用量[MRAR]的33%）对马铃薯晚疫病的防治效果不理想。在有利于晚疫病发生的中等条件下，两种杀菌剂以MRAR的33%至66%施用可有效防治。密歇根州立大学的高级选育品系MSG274-3是所测试的最不易感的ABL，在1998年至2000年期间，使用降低剂量的杀菌剂有效控制了晚疫病。与未处理对照相比，百菌清的施用量（MRAR的33%至100%）显著降低了品种Snowden的晚疫病（5天施药间隔）；然而，在1999年或2000年，即使百菌清以100%MRAR在10天或15天施药间隔下施用，Snowden的晚疫病也未得到有效控制。ABL MSG274-3是本研究中使用的所有品种和ABL中最不易感的，对晚疫病所需的化学保护最少。该研究表明，对晚疫病易感性降低的ABL可以通过降低杀菌剂施用量和延长施药间隔来管理，从而提供对这种病害更经济的防治方法。
