Abstract: Summer patch caused by Magnaporthe poae is a recently discovered fungi disease with great destructibility which affects the turf grass root,especially the Kentucky bluegrass.It has become one of the main turf diseases in north China.The prevention and cure of summer patch is still in a primary stage and the chemical control is the main way.The purpose of this study was to find out whether or not a synergistic action between plant growth regulators and fungicides on the control efficiency of summer patch.Study was conducted to assess the interactions among two plant growth regulators(PGRs),trinexapac-ethy and paclobutrazol,three fungicides,azoxystrobin,thiophanate-methyl,and mancozeb on Kentucky bluegrass infected by summer patch.The results show that all the five reagents were fungistatic to the Magnaporthe poae in vitro and the effectiveness as the follows: azoxystrobin > thiophanate-methyl > mancozeb> paclobutrazol > trinexapac-ethyl.In the pot and field experiment,the conclusions were similar: PGRs alone treatment had certain inhibitory effect to the summer patch.The plot treated with both PGRs and fungicides showed less disease index than the plot with PGRs or the fungicides alone.Meanwhile,the synergistic action also dwarfed the lawn and promoted the growth of grass root.

Key words: Summer Patch, Plant growth regulators(PGRs), Synergistic action, Disease index

摘要： 为测定植物生长调节剂与杀菌剂互作是否对夏季斑防治具有增效作用,于2007年8月主要测定了2种植物生长调节剂抗倒酯(Trinexapac-ethyl)、多效唑(Paclobutrazol)和3种杀菌剂绘绿(Azoxystrobin)、甲基拖布津(Thiophanate-methyl)、代森锰锌(Mancozeb)对早熟禾(Poa pratensis L.)夏季斑的防治效果。结果表明:在培养皿中,5种药剂对夏季斑的生长均具有抑制作用,抑菌效果从高到低依次是绘绿,甲基拖布津,代森锰锌,多效唑,抗倒酯;在盆栽和大田实验中,单独施用植物生长调剂对夏季斑具有一定抑制作用;与杀菌剂互作后,不但提高了对夏季斑的防治效果,而且矮化了草坪,促进了草坪根部的生长。

关键词: 夏季斑, 植物生长调剂, 互作, 发病指数