Control of root rot of Atractylodes macrocephala Koidz

The fine roots of the symptomatic plant turned brown and rotten, and then spread to the upper fleshy rhizome and stem, showing dark brown sunken rot spots, and the aboveground began to wilt. The vascular bundles showed obvious discoloration circle in the rhizome and stem cross-section. in the later stage, the rhizomes all turned into spongy black dry rot, and the plants died and were easy to be pulled out from the soil. The occurrence of dry rot, stem rot and wet rot is common in both new and old producing areas, which seriously affects the yield and quality.

The pathogen and its occurrence regularity are mainly caused by Fusarium oxysporum (Fusarium oxysporumSchl.), which is reported to be caused by multiple Fusarium oxysporum. Soil disease residue carrying bacteria is the source of disease infection, and heat during seed storage reduces the disease resistance of seedlings, which is the main cause of the disease. Poor root development caused by soil flooding, sticky weight or application of immature organic fertilizer, and easy to occur after wounds caused by nematodes and underground pests. In the middle and later stage of growth, if it clears up after continuous overcast and rain, and the temperature increases, the disease will be serious. The peak period of the disease was from June to August.

① selected sandy loam with high dryness and good drainage, shallow ploughing should avoid root damage, and strengthen the control of underground pests and nematodes. ② reasonable rotation, select strong disease-resistant dwarf broad-leaf varieties; select robust disease-free planting, keep the seed fresh during storage to prevent water loss and dryness after fever. ③ pulled out the diseased plants in the early stage, and irrigated the disease with 50% carbendazim or 70% methyl topiramate 800x solution; soak the seeds with 50% carbendazim 500x solution for 6 minutes for 8 minutes before planting, fish out and dry after planting.