The Influence Of Irrigation On Summer Patch Of Kentucky Bluegrass

Summer patch is a very serious disease on Kentucky bluegrass(Poa pratensis L.).This research concerns with Summer patch on Kentucky bluegrass and irrigation management which is one of the most important turf management factors.Mainly including the influence of irrigation management on growing state of Kentucky bluegrass and summer patch on Kentucky bluegrass.Irrigation management influences on temperature & humidity factor.Interrelated temperature & humidity factors are chosen to establish pertinence model of disease percentage and disease index of summer patch on Kentucky bluegrass.The main results are as follows:1.Character culture of pathogenicbacteria of summer patch(Magnaporthe poae) in three different culture mediums:1/4PDA,1/2PDA and PDA.The pathogenicbacteria is growing best in PDA.2.The irrigation method of lower quantity of water everyday as F1 can prevent Kentucky bluegrass from summer patch a certain extent,and defer occurrence of disease,but can not contain it. Under the irrigation method of low frequency and higher quantity of water as F3,Kentucky bluegrass will get summer patch easier,and the irrigation method can make it more serious.Under lacking water as Q1,Kentucky bluegrass will get summer patch easier than those under enough water as Q6,but the development of disease is slower than those under enough water.F1 is the best irrigation mode.3.Irrigation management influences on temperature & humidity factor:5cm soil temperature, temperature and relative humidity of turf top,temperature and relative humidity of the layer of turf rhizoma.In occurrence period,fastigium period and telophase period of the disease,interrelated temperature & humidity factors are chosen with multiple liner regression analysis,to establish pertinence model of disease percentage and disease index of summer patch on Kentucky bluegrass. occurrence periodpertinence model of disease percentage:X₁= -230.852+7.331Tuh- 0.171Hspertinence model of disease index:Y₁= -109.990+2.928Tt+0.141Hs fastigium periodpertinence model of disease percentage:X₂ =-205.410+55.668Ts-57.614Tth+10.742Tu-0.263Hs pertinence model of disease index:Y₂=123.807+58.551Ts-58.634Tt-0.704Hs telophase periodpertinence model of disease percentage:X₃=-733.578+27.867Ttpertinence model of disease index:Y₃=-660.610+24.995Tt...