Atractylodes macrocephala pest and disease control methods and technical key points

The main diseases of Atractylodes macrocephala includeAtractylodes macrocephala leaf spot (Septoria leaf spot)(Septoria leaf spot),Atractylodes macrocephala ring spot(Ascochyta leaf spot),Atractylodes macrocephala root rot、Atractylodes macrocephala southern blight、Atractylodes macrocephala mosaic virus disease; insect pests includeAtractylodes macrocephala root-knot nematode disease、red flower tube aphid、green leafhopper、peach fruit borer. The following introduces the symptoms and control methods of these pests and diseases.

I. Diseases

1. Atractylodes macrocephala leaf spot(Septoria leaf spot)

leaf spotsymptoms: Mainly damages leaves. Brown or dark brown spots of varying sizes appear on the leaves. The development of the spots is often restricted by leaf veins, appearing nearly circular, polygonal or irregular. In the later stage, the color of the spots becomes slightly lighter. Black dots appear on the surface. The spots are numerous and merge with each other, causing leaf blight. Leaf petioles and stems can also be affected, with dark brown elongated spots forming on the diseased parts.

Atractylodes macrocephala leaf spot

leaf spotpathogen: Septoria atractylodisSeptoria atractylodis Y.S. Yu et K. T. Chen. Belongs to Deuteromycotina, Sphaeropsidales, Septoria. Pycnidia are borne on the leaf surface, dark brown spherical, initially immersed, later breaking through the epidermis, with the ostiole exposed, circular, dark brown. Conidia are colorless, filiform, straight or curved, with 1—5 septa.

leaf spotoccurrence characteristics: Occurs commonly and causes severe damage. The pathogen overwinters as pycnidia on diseased plant residues in the field. The following year, conidia cause primary infection. Diseased seed roots used for planting are also a source of primary infection. After disease onset in the field, the pycnidia on the spots release conidia when moistened by rain, and are spread by wind and rain splash, continuously causing secondary infection. The peak period of the disease is in the middle and late stages of Atractylodes macrocephala growth. During this period, there is abundant rain and the disease occurs severely, causing large numbers of plant leaves to wither and die, greatly affecting yield and quality.

leaf spotcontrol key points: (1) After harvest, remove diseased plant residues from the field to reduce sources of primary infection. (2) Cultivate disease-free rhizomes (planting stock) for planting. Or before planting, soak or spray the seed rhizomes with carbendazim, and plant with the chemical. (3) Chemical control: In the early stage of disease onset, apply broad-spectrum fungicides such as Bordeaux mixture, carbendazim, and chlorothalonil. Atractylodes macrocephala leaf spot

2. Atractylodes macrocephala ring spot(Ascochyta leaf spot)

ring spotsymptoms: Spots occur at leaf tips, leaf margins and the center of leaves, appearing dark brown, circular or semicircular, with obvious concentric rings. In the later stage, the center of the spots becomes slightly lighter, appearing light brown, while the edges remain dark brown, with black dots (pycnidia) scattered on the surface.

 Atractylodes macrocephala ring spot

ring spotpathogen: An Ascochyta speciesAscochyta sp., belonging to Deuteromycotina, Sphaeriales, Ascochyta. Pycnidia are spherical, brown, scattered on the leaf surface, a few clustered, initially immersed then breaking through the epidermis, with the ostiole exposed; conidia are colorless, cylindrical, straight, with both ends bluntly rounded, with one septum in the center, not constricted at the septum.

ring spotoccurrence characteristics: Sporadic occurrence in Baoxing County and Tianquan County, Sichuan, with severe occurrence in some plots. The pathogen overwinters as pycnidia on diseased leaf residues in the field, and infects via conidia the following year. After disease onset, new pycnidia and conidia form on the spots. The pycnidia produce turgor pressure when exposed to rain, releasing conidia, which are spread by rain splash, continuously causing secondary infection. The disease can occur from May to October, with the peak period from July to August. During this period, there is abundant rain and severe disease occurrence.

ring spotcontrol key points: (1) After harvest, remove and destroy plant residues from the field to reduce sources of primary infection. (2) Chemical control of Atractylodes macrocephala leaf spot can simultaneously control this disease. 

3. Atractylodes macrocephala root rot

root rotsymptoms: Damages the stem base, roots and rhizomes. In mildly affected plants, the lateral roots become brown and necrotic, and the plants grow poorly. When the rhizome and stem base are affected, the diseased parts become brown and rot, and finally become hollow, exposing the fibrous vascular bundles. The aboveground parts of the plant completely wither and die, and diseased plants are very easily pulled up.

Atractylodes macrocephala root rot 

root rotpathogen: Fusarium oxysporum Fusarium oxysporum Sehlecht. Belongs to Deuteromycotina, Tuberculariales, Fusarium. Macroconidia are crescent-shaped, colorless, multi-septate. Microconidia are elliptical, ovoid, colorless, 1-2 septate. According to reports, there are other Fusarium species.