The invention discloses a method for preventing and treating
panax notoginseng round spot. The method comprises the following steps of: constructing an arched tunnel of which the
arch height is 1.2cm and the arch width is more than soil
moisture width and less than the sum of the moistened soil width and the width of
drainage ditch between the moistened soils on each moistened
soil surface where
panax notoginseng is planted in a panax notoginsen shade-shed, wherein the arched tunnel is constructed by reinforcing steel bars or bamboos; covering a
plastic film on the outer surface of the arched tunnel in a rainy day and ensuring that the edge of the
plastic film is sagged to the bottom surface of the
drainage ditch between the moistened soils; and uncovering the film when the rain stops. With the adoption of the method, the newly-increased
disease strain rate of the round spot is reduced by over 90 percent, that is, the loss is recovered by 90 percent, and the grade of the
disease strain only reaches a grade 1; and meanwhile, the newly-increased
disease strain rate of
epidemic disease is reduced by over 95 percent. In addition, because newly-increased disease strains are unavailable to
melasma, gray mold and
powdery mildew, the dosage quantity of sterilizing agents and artificial insecticide spraying expense are reduced, the planting cost is saved, the yield of
panax notoginseng is increased, the quality of panax notoginseng is improved and the income is increased; and moreover, the arched tunnel uses simple materials and is easy and convenient to operate.