Introduction of several common diseases and insect pests of Atractylodes macrocephala Koidz and their prevention and control techniques

Atractylodes macrocephala Koidz is a kind of traditional Chinese medicine with high economic value and medicinal value. it has developed rapidly in recent years, but the planting technology is high. It often causes large area withering and death because of continuous cropping, not paying attention to soil disinfection, high temperature and heavy rain in the growing period and so on. At the request of farmers who plant medicinal materials, several common diseases and insect pests of Atractylodes macrocephala Koidz and their prevention and control techniques are introduced.

I. Diseases

1. The incidence characteristics of major diseases. ① white silk disease. The disease is mainly harmful to the rhizome of Atractylodes macrocephala Koidz, and there are no obvious symptoms in the aboveground part at the initial stage of the disease. In the later stage, with the increase of temperature and humidity, the hyphae penetrated the soil layer, the white hyphae were covered with rhizomes and the surrounding soil surface, and the top tips of the killed plants withered and drooped, and finally the whole plant withered. Soil and residue of Atractylodes macrocephala is an important source of infection of the disease. During the onset period, the hyphae spread and the sclerotia were re-infected with the flow of water. The disease can occur from late April to September, and the peak period is the high temperature and humidity season from early June to early August. ② root rot. The disease is a vascular bundle system infection disease. at the beginning of the disease, some lateral roots turn brown and dry rot, and then spread to the rhizome and aboveground, making the rhizome rot and the branches and leaves wilting. Soil and residue of Atractylodes macrocephala is the main source of primary infection, and the activity of underground pests frequently aggravates the occurrence of the disease. The disease occurs when the temperature is 22 ℃ ~ 28 ℃ and the relative humidity is 80% ~ 90%. The disease began in the middle of April and reached its peak from June to July. ③ iron leaf disease. The disease was thought to be mainly harmful to the leaves, which first occurred from the basal leaves and gradually spread upward. At the initial stage of the disease, small yellow-green spots appeared on the leaves, but in the later stage, the spots expanded and connected into large iron-black spots, which soon covered the whole leaves. The disease and residual body is the source of primary infection, which usually begins from late April to early May, the peak period is from June to August, and the disease is the fastest before and after bud picking.

two。 Prevention and control methods. Comprehensive measures should be taken for prevention and control. When ① is planted every year, trichloroisocyanuric acid must be used for soil disinfection. In the early stage of ②, 50g Jiazhixin Qifeng (imported multi-element foliar fertilizer) was sprayed on the base of stem to control the further occurrence of the disease. White silk disease is easy to occur in ③ from May to early July and from early September to mid-October, especially in high temperature, muggy, rainy and humid weather. The withered plant was found in the field, and there was white matter at the base of the stem. The diseased plant was pulled out immediately and lime was applied. The stem base was sprayed with Zhixin 101 or 800 times solution of cupric cyanide plus 50 grams of fine Wanjiafeng (copper oleate) plus Guofeng (high potassium foliar fertilizer). From early June to early September, ④ was prone to root rot, iron leaf disease and blight. Chemical control was carried out immediately after bud picking, and the whole plant was sprayed with 72.2% paracetamol water agent 40ml plus trichloroisocyanuric acid 35g plus high potassium fertilizer per mu. Prevention and treatment every 10 days, 3 times in a row.

II. Insect pests

The main control at seedling stage is grub, small land tiger, mole cricket and other underground pests. Sprinkle 1.5kg of poisonous soil with 50% phoxim EC or 48% chlorpyrifos EC; from emergence to harvest, spray with 0.36% matrine 60 ml or 3% acetamiprid 1000 times per mu according to the occurrence degree of aphids.