Interactive Effects Of Plant Growth Regulators And Fungicides On Summer Patch

Summer patch,also called summer spot blight or summer ring spot,is one of the main disease of cool season grasses.It is caused by Magnaporthe poae and is a root disease with great destructibility. Studies was conducted to separate and identify the Magnaporthe poae form the sick.Kentucky bluegrass and to assess the interactions among two plant growth regulators(PGRs) Trinexapac-ethy, Paclobutrazol three fungicides Azoxystrobin,Thiophanate-methyl and Mancozeb on summer patch.The main results are as follows:(1) The growth of Magnaporthe poae is affected by temperature and pH.In the set temperature of 20℃,25℃,30℃,35℃,the most suitable one is 27℃—30℃.And in the set pH of 5.0,5.5,6.0,6.5,7.0,7.5,8.0,8.5,9.0,the most suitable one is 5.5—6.0.(2)All the five reagents were fungistatic to the Magnaporthepoae in vitro,which respectively are Azoxystrobin＞Thiophanate-methyl＞Mancozeb＞Paclobutrazol＞Trinexapac-ethyl.The fungicide have better fungistatic to Magnaporthepoae than PGA.(3)In the pot and field experiment.the conclusions are similar:PGRs alone treatment shows little or inhibitory effect to the summer patch.However.the plot with both PCiRs and fungicides shows less disease index than the plot with PGiRs or the fungicides alone.Meanwhile.it also dwarf the lawn and has a good effect to the growth of grass root.