Control of diseases and insect pests of atractylodes macrocephala

The main diseases of Atractylodes macrocephala include Atractylodes macrocephala spot disease, Atractylodes macrocephala root rot, Atractylodes macrocephala root rot, Atractylodes macrocephala mosaic virus, Atractylodes macrocephala root knot nematode, safflower finger tube aphid, big green leafhopper and peach borer. The following introduces the performance characters and control methods of its diseases and insect pests.

I. Diseases

1. Spot blight of Atractylodes macrocephala (Alternaria alternata)

Symptoms of spot blight: mainly harmful leaves, brown or dark brown spots of different sizes on the leaves, and the development of disease spots is often nearly round, polygonal or irregular due to the limitation of leaf veins. The color of the lesion was slightly lighter in the later stage. The surface is black and small. The disease spots are many and heal each other, causing the leaves to wither. Petioles and stems can also be damaged, and the diseased part has dark brown long spots.

Atractylodes macrocephala spot blight

The pathogen of spot blight: Septoria atractylodis Y.S. Yu et K. T. Chen. It belongs to the subphylum of semi-known bacteria, Cercospora, Cercospora. Conidium foliar, dark brown spherical, initially buried, then break through the epidermis, orifice exposed, round, dark brown. Conidia colorless, linear, straight or curved, 1 Mel 5 septum.

The occurrence characteristics of spot blight: the occurrence is common and the harm is serious. The pathogen overwintered on the diseased remains in the field with conidia, and the initial infection was carried out with conidia in the following year, and the diseased root was also the source of primary infection. After the disease occurred in the field, the conidia on the disease spot were wetted by Rain Water and released the primary conidia, which were spread by wind and rain sputtering and continuously caused re-infection. The epidemic period of the disease was in the middle and later stage of the growth of Atractylodes macrocephala Koidz, at this time, there were many Rain Water, and the disease occurred seriously, resulting in a large number of withered leaves of the plant, which had a great impact on the yield and quality.

Key points of control of leaf spot blight: after ① harvest, the disease residue in the field was removed and the source of primary infection was reduced. ② cultivated disease-free rhizome (technical planting). Or the rhizome soaked or sprayed with carbendazim before planting and planted with medicine. ③ chemical control: in the early stage of the disease, spectral fungicides such as Podoll solution, carbendazim and chlorothalonil were applied. Atractylodes macrocephala spot blight

2. Atractylodes macrocephala ring disease (shell bisporium leaf spot)

Symptoms of ring disease: the disease spot occurs in the leaf tip, leaf edge and the center of the leaf, showing dark brown, round or semicircular disease spot, with obvious wheel pattern. In the later stage, the middle color of the lesion was slightly light brown, the edge remained dark brown, and the surface was scattered with black dots (conidium).

Atractylodes macrocephala ring disease

The pathogen of ring disease: a semi-knowing subphylum of Ascochyta sp., Chlorella, Chlamydomonas. The conidium is globose, the brown leaf surface is scattered, a few accumulate, break through the epidermis after burial, and the orifice is exposed; the conidia is colorless, cylindrical, upright, obtusely round at both ends, with a septum in the center and not constricted at the septum.

The occurrence characteristics of ring disease: sporadic occurrence in Baoxing County and Tianquan County, Sichuan Province, and severe occurrence in local plots. The pathogen overwintered with conidia in the remnants of diseased leaves in the field and was infected by conidia in the following year. After the onset of the disease, molecular spore apparatus and conidia were newly formed on the lesion. The conidium produced turgor when it met Rain Water and released the conidia. The conidia were spread by Rain Water sputtering and re-infected continuously. The disease can occur from May to October, and the peak period is from July to August, during which Rain Water is more and the disease is serious.

Key points of prevention and control of ring disease: after ① harvest, the plant remains in the field were removed and destroyed to reduce the source of primary infection. ② can be used to control spot blight of Atractylodes macrocephala Koidz.

3. Root rot of Atractylodes macrocephala Koidz

Symptoms of root rot: damage to stem base, root and rhizome. The branch roots of lightly infected plants turned brown and necrotic, and the plants grew poorly. When the rhizome and stem base were killed, the diseased part became brown and rotted, and finally became empty, exposing fibrous vascular bundles, the aboveground part of the plant completely withered, and the diseased plant was easily uprooted.

Root rot of Atractylodes macrocephala Koidz

The pathogen of root rot: Fusarium oxysporum Fusarium oxysporum Sehlecht. It belongs to the subphylum of semisciferous bacteria, the order Alternaria, the genus Fusarium. Macroconidium heart-shaped, colorless, septate. Conidia elliptic, ovoid, colorless, 1-2 septate. Other Fusarium oxysporum are reported.