Inglis D A, Powelson M L, Dorrance A E
Washington State University-Mount Vernon Research and Extension Unit, 16650 State Route 536, Mount Vernon 98273-9761.
Department of Botany and Plant Pathology, Oregon State University 97331.
Plant Dis. 1999 Mar;83(3):229-234. doi: 10.1094/PDIS.1999.83.3.229.
Curative applications of thiophanate-methyl + mancozeb to blighted seed pieces of three potato (Solanum tuberosum) cultivars significantly reduced the amount of surface area colonized by Phytophthora infestans compared with treatment with thiophanate-methyl or no fungicide under laboratory conditions. Percent blighted tuber surface area over six tests averaged 3.5, 11.4, and 21.2% for the three treatments, respectively. Seed pieces inoculated with P. infestans US-8 or US-11 incubated, and then treated with the same fungicides and planted at Oregon and Washington field sites, respectively, had higher emergence across locations for thiophanate-methyl + mancozeb than for thiophanate-methyl (30 versus 12.5%). Emergence of healthy thiophanate-methyl + mancozeb-treated seed pieces averaged 93%. When protective applications of these fungicides, mancozeb, or fludioxinil were made to healthy potato seed pieces prior to inoculation with P. infestans, plant emergence in the greenhouse was significantly increased with thiophanate-methyl + mancozeb compared with fludioxinil (92 versus 36%) in Oregon and with thiophanate-methyl or fludioxinil (90 versus 20 and 24%) in Washington. Inoculation of healthy seed pieces reduced plant stand in all greenhouse tests; however, treatment with thiophanate-methyl + mancozeb or mancozeb alone prior to inoculation resulted in sprout emergence similar to that of the noninoculated control. In a late blight management program, treatment of seed pieces with a registered fungicide that has activity against P. infestans contributes to an increase in plant emergence and improved crop uniformity. However, for maximum benefit, the fungicide must be in place before coming in contact with the pathogen.
在实验室条件下，与使用甲基托布津或不使用杀菌剂的处理相比，甲基托布津 + 代森锰锌对三种马铃薯（Solanum tuberosum）品种的带病种薯进行治疗性处理，显著减少了致病疫霉的定殖表面积。在六次试验中，三种处理的病薯表面积百分比平均分别为3.5%、11.4%和21.2%。分别用致病疫霉US - 8或US - 11接种、孵育，然后用相同杀菌剂处理并分别种植于俄勒冈州和华盛顿州田间的种薯，甲基托布津 + 代森锰锌处理的种薯在各地的出苗率高于甲基托布津处理的种薯（分别为30%和12.5%）。经甲基托布津 + 代森锰锌处理的健康种薯出苗率平均为93%。在接种致病疫霉之前，对健康马铃薯种薯进行这些杀菌剂、代森锰锌或咯菌腈的保护性处理时，在俄勒冈州，甲基托布津 + 代森锰锌处理的温室植株出苗率显著高于咯菌腈处理（分别为92%和36%）；在华盛顿州，甲基托布津 + 代森锰锌处理的温室植株出苗率显著高于甲基托布津或咯菌腈处理（分别为90%、20%和24%）。在所有温室试验中，接种健康种薯均降低了植株成活率；然而，在接种前用甲基托布津 + 代森锰锌或仅用代森锰锌处理，其芽苗出苗率与未接种对照相似。在晚疫病管理计划中，用对致病疫霉有活性的登记杀菌剂处理种薯有助于提高植株出苗率并改善作物一致性。然而，为了获得最大效益，杀菌剂必须在接触病原体之前施用。
