The invention discloses a simple method for rapidly detecting 
physalospora piricola infection amount in apple branches, and relates to a 
rapid detection technology for 
pathogen infection amount in plants. The method is suitable to detect 
pathogen quantity of living apple branches whose 
diameter at the base is smaller than 3 cm. The specific method comprises: 
girdling a cortex on the base of a to-be-detected 
branch, width being 2-10 mm; using a 
paraquat liquor whose 
active ingredient content is 60 g / L - 100 g / L to soak absorbent paper, 
degreasing cotton, and cotton threads or cloth strips, after taking the absorbent paper, the 
degreasing cotton, and the cotton threads or cloth strips out and draining, winding the absorbent paper, the 
degreasing cotton, and the cotton threads or cloth strips on a 
girdling opening position, using an 
adhesive tape or a 
plastic film to wrap tightly; from the third day after 
processing, inspecting and recording the number of lenticels which are diseased and not diseased on the branches, and whether a 
necrosis cortex generates pycnidium or not. The method is advantaged in that the method detects clearly whether apple branches have potential 
physalospora piricola in 1-2 weeks, and the quantity of potential 
pathogen, and the method is simple in operation method and reliable in detection result, and solves a problem that a conventional survey cannot detect 
physalospora piricola infection amount in branches.