Latest Technical Methods and Tutorial for American Ginseng Pest and Disease Control

American ginseng is a precious traditional Chinese medicinal herb. It can treat chronic cough due to lung deficiency, blood loss, dry throat and thirst, and irritability with deficiency heat. China has over a hundred years of application history. Originally, it was mostly imported from the United States and other countries. Now, introduction and cultivation have succeeded in Jilin, Liaoning, Heilongjiang, Shaanxi, Jiangxi, Guizhou, Yunnan, Hebei, Shandong, Anhui, and Fujian provinces. Let us now take a look at the pest and disease control techniques for American ginseng!

Black Spot Disease

[Disease Characteristics] Black spot disease, also known as spot disease, has an incidence rate of 20-30%. It spreads rapidly during the rainy season or when humidity is high, so early prevention and early treatment are essential. In the early stage of the disease, irregular brown spots appear on the leaves, petioles, and stems, gradually expanding and becoming sunken, producing a black velvety mold layer. The leaves wilt, and the plants collapse early and die. After the fruit is infected, a dark brown mold layer is produced, and the fruit shrivels and drops off. Plants aged 3-4 years are more severely affected than those aged 1-2 years.

[Control Methods] After the ginseng seedlings unfold their leaves, use mancozeb 800x solution or amobam 500-800x solution, and spray evenly on both sides of the leaves and all parts of the plant. Promptly pull out and burn diseased leaves and diseased plants to eliminate the source of infection.

Damping-off

[Disease Characteristics] Damping-off is a disease that occurs relatively easily during the seedling stage of American ginseng. In severe cases, ginseng seedlings die in patches. In the early stage of the disease, water-soaked dark green lesions appear on the base of the stem near the ground, quickly expand, and the stem shrinks and softens, causing the plant to lodge and die.

[Control Methods] Generally, spray with 400x Bordeaux mixture or 800-1000x mancozeb aqueous solution, which also controls other diseases. The ginseng field should have good drainage and ventilation, avoiding excessive humidity. Immediately remove diseased plants, and disinfect the surrounding area with 400x formaldehyde aqueous solution or lime water to eliminate the source of infection.

Rusty Root Rot

[Disease Characteristics] After infection at the bud at the seed crack and on the roots and rhizome neck, rust-colored yellowish-brown lesions appear, gradually expanding and causing destruction of internal tissues. Small granular substances (pathogen spore masses) are produced at the diseased sites, and continued reproduction causes the epidermal layer to rupture and rot. It is generally spread by diseased seeds and seedlings, diseased root residues, soil water infection, and human activities.

[Control Methods] The peak incidence period is from June to August. Seeds and seedlings must be strictly quarantined. Diseased plants should be dug out early, the soil should be sterilized with lime, and routine drainage and ventilation should be maintained, with weeds burned. Soak with mancozeb 800x aqueous solution, polyoxin 200 units, or amobam 500-800x aqueous solution for 8-15 minutes, then air-dry before transplanting. Seeds, whether carrying bacteria or not, must be treated with chemicals.

Seedling Blight

[Disease Characteristics] Infection mostly occurs at the base of the seedling stem, 3-5 cm from the surface soil at the boundary between dry and wet soil. The young stem shows yellowish-brown sunken elongated lesions, gradually rotting inward. The vascular tissue is destroyed and the plant lodges and dies, hence the name seedling blight. This disease is generally more likely when seedlings are too dense and growth is poor.

[Control Methods] For soil and seed disinfection and sterilization, 400x Bordeaux aqueous solution, 400x carbendazim aqueous solution, and 800x mancozeb or amobam aqueous solution are commonly used. Apply 4 kg of solution per square meter, allowing it to penetrate 3-5 cm into the soil layer, then spray clean water to wash the leaves to prevent chemical injury.