Conidium Occurrence And Canker Spot Expansion Of Pear Valsa Canker And Its Mix-fungicides Screening

In China,serious harm has been caused by pear diseases in the main stem.At present,effective prevention and low toxicity chemicals are still in need.So the main purpose of this research was to investigat the conidia dispersal dynamics at specific locations and periods,the lesion year-round expansion dynamics,the optimization of indoor inhabiting effect and the screening experiment of combination fungicides,the indoor inhabiting effect and indoor inhabiting effect of compound fungicides to master the epidemic rules and find efficient fungicides.The main results are as follows:l,the conidia anniversary occurrence survey showed conidia pear rot disease can be spread from March to October and stoppped in November.In April,May and July,the peak of dissemination,among which the April and May hits the highest point.Analyzing from the seasonal capture of conidia,the annual peak spring follows by summer.Conidia stops spreading in winter.2,lesion anniversary of the expansion rules survey results show that rot lesion extended from March to November and stopped extension from December to February when in its dormancy.Peak of Lesion expansion comes in April and September.The Lesion expands most quickly in September.During April to September,the pear vigorous growth period.lesion size expansion,incremental growth trend in "V" type.Description of pear canker lesion in the pear tree in the vigorous growth period,valsa canker activity is weak and spread slowly,it stops expansion in the cold winter.3,In the optimization of indoor bacteriostatic test,red ink was mixed in the fungicides to survey its ability of extension and permeability.At the mean time,through the optimization of the fungicides formul,the effect of the fungicides on the mycel.4,the indoor inhabiting effect and field trials experiment of compound fungicides show that to triadimenol(szc):azoxystrobin mjz = 2:1 as basic compound fungicides.In bacteriostatic test indoor,adding 100 UG/ml of 6-BA,100 ug/ml of NAA and 0.025%Si or 200 ug/ml of 6-BA,200 ug/ml of NAA and 0.025%Si inhibitory effect best;in the field treatment tests,optimal cure of pear canker disease fungicides dosage proportion of 6-BA 200ug/I,200mg/L NAA and 0.025%Si.The preliminary screening of the fungicides finds the compound fungicides which shows high efficiency in the valsa canker prevention.The annual spread of the spores and lesion extension are researched.It shows great meaning in chosing the prevention measures and obtaining the high efficiency and low toxicity medicament.But further study is still needed.