Control techniques of Diseases and insect pests of American Ginseng

American ginseng is a valuable traditional Chinese medicine, which can treat lung deficiency and chronic cough, blood loss, dry pharynx, thirst, deficiency heat and irritability. It has been used in China for more than a hundred years, and it was mostly imported from the United States and other countries. Now that it has been successfully introduced and cultivated in Jilin, Liaoning, Heilongjiang, Shaanxi, Jiangxi, Guizhou, Yunnan, Hebei, Shandong, Anhui and Fujian provinces, let's take a look at the pest control techniques of American ginseng.

Black spot disease

[morbidity characteristics] Black spot, also known as spot disease, has an incidence of 20-30%. It spreads quickly in the rainy season or high humidity, so it should be prevented and treated as soon as possible. In the early stage of the disease, there were irregular brown spots on the leaves, petioles and stems, which gradually expanded and sunken, resulting in a black velvet mold layer, the leaves withered, the plants collapsed and the seedlings died in the early stage. After the fruit is infected, it produces a black-brown mildew layer and the dry chaff falls off. The disease of 4-year-old plants was more serious than that of 1-2-year-old plants.

[control method] after spreading the leaves of ginseng seedlings, 800-fold solution of mancozeb or 500-fold solution of ammonium mancozeb was used to spray the front and back of the leaves and all parts of the plant evenly. Diseased leaf disease plants were found to be pulled out and burned in time to eliminate the source of the disease.

Cataplexy

[incidence characteristics] quenching disease is a kind of disease easy to occur in the seedling stage of Panax quinquefolium, and the seedlings die in serious cases. In the early stage of the disease, water-stained dark green disease spots appeared at the stem base near the ground of the seedlings, which expanded quickly, and the stem contracted and softened and lodged and died.

[control methods] generally use 400-fold Bordeaux liquid or 800-1000-fold mancozeb water spray to prevent other diseases. The garden should be well drained and ventilated to avoid excessive humidity. Disinfect the diseased plant immediately and disinfect it with 400 times formaldehyde solution or lime water around to eliminate the source of the disease.

Rust rot

[characteristics of the disease] ferruginous yellow-brown disease spots appeared in the spores and roots of seeds and Reed heads after infection, which gradually expanded, resulting in the destruction of internal tissue, and small granular substances (pathogenic spores) were produced at the site of the disease. continue to breed to make the epidermis break and rot. It is generally transmitted by diseased seedlings, diseased root residues, soil water contamination and human activities.

[prevention and control methods] the peak period of the disease is from June to August, and the seedlings must be strictly quarantined. it is found that the diseased plants should be collected in advance, the soil should be disinfected and sterilized with lime, and the weeds should be burned by drainage and ventilation. Soak in 800-fold mancozeb, 200 units of polyantimycin or 500-800-fold mancozeb for 8 minutes, then dry before transplanting. Whether the seeds are infected or not, they need to be treated with chemicals.

Blight disease

[characteristics of the disease] the disease is mostly at the junction of dry and wet soil at the base of the seedling stem, which is 3cm away from the topsoil. The young stem shows a long yellow-brown sunken spot, gradually rots inward, and the conducting tissue is destroyed and lodged to death, so it is called Rhizoctonia solani. Generally, the seedlings are too dense and are easy to catch the disease when they are not growing well.

[control methods] in the disinfection and sterilization of soil and seeds, 400-fold Bordeaux solution, 400-fold aqueous solution of carbendazim and 800-fold aqueous solution of mancozeb and ammonium are commonly used to prevent and cure the disease. The solution is 4 kg per square meter and penetrates into the soil layer 3-5 cm deep. Then spray clean water to wash leaves to prevent drug damage.

Anthrax

[disease characteristics] it is mainly harmful to diseased leaves, fruits and stems can also be damaged. The lesion on the leaf is bilateral, orbicular or suborbicular, 2-6 mm in diameter. The lesion is yellow-white in the center, reddish brown on the edge, thin and brittle, easy to rupture and perforate when dry, and many black spots grow in the later stage of the disease, which is the conidium disk of the bacteria. The disease spot on the stem is oblong, the center is light brown, and the margin is yellowish brown. The disease is perishable in wet weather.

[occurrence regularity] the pathogen is Ginseng anthracnose, which belongs to the subphylum of half-known bacteria, and anthrax is a fungus. The pathogen overwintered on the stump of the diseased plant with conidia disk and mycelium, or attached to the seeds as conidia. When the conditions are suitable in the next spring, the initial infection is caused by the transmission of wind and rain, and many times of re-infection can occur in the growing season. High temperature and drought are beneficial to the occurrence of the disease, and the peak period is from July to August.

[control methods] after autumn, ① cleared the aboveground stems and leaves and burned them centrally. After fully spreading leaves in spring, ② plants were sprayed with Bordeaux solution for protection, and 75% chlorothalonil 500 times or 50% mancozeb 600 times were sprayed 1-2 times during the onset period.

American ginseng blight

[characteristics of the disease] all parts of the plant were damaged. The injured leaves and petioles were flooded and dark green, such as boiling water was scalded, and the diseased part became dark green and softened and sagged. After the root is injured, it shows yellowish brown soft rot, the root bark is easy to peel off, the interior is yellowish brown, and shows a dark yellowish brown pattern, which gives off a fishy smell. In the later stage, the roots of ginseng were attached with white hyphae and adhered to clumps of soil.

[occurrence regularity] the pathogen is Phytophthora, which belongs to the subphylum flagellum and Phytophthora belongs to fungi. The pathogen overwintered with oospores or mycelia on the diseased remains or in the soil and became the source of infection at the beginning of the next year. Wind, rain and running water are the main ways of transmission of the disease. The disease is usually prevalent when the average temperature is more than 20 ℃ and the soil moisture is more than 40% from June to August. Heavy sticky soil, overdense plants and poor ventilation and light transmission are beneficial to the occurrence of the disease. When the disease is serious, it causes a large area of plant death.

[prevention and treatment methods] ① was protected by spraying 1 Bordeaux solution in the middle of June. During the rainy season, ② was sprayed 3-4 times with 50% mancozeb 600x solution, 40% mancozeb 800x solution or 200x agricultural antibiotic 120x spray.

Sclerotinia disease

[disease characteristics] damage more than 3-year-old ginseng roots. Ginseng root is yellowish brown, infiltrating, soft rot in internal tissue, a little white villous mycelium on the outside, and rat dung-like, irregular sclerotia formed in the later stage. In the end, the corruption of the tissue in the root dissolves, leaving only the outer skin. There was no difference between the aboveground part and the healthy plant in the early stage, but wilted and withered in the later stage.

[occurrence regularity] the pathogen is Sclerotinia sclerotiorum, which belongs to the subphylum ascomycetes. The pathogen overwintered with sclerotia on the remains of the diseased plant and in the soil. When the soil temperature was suitable in the next spring, sclerotia germinated and infected ginseng roots. 6-8 ℃ was the most favorable for the occurrence of Sclerotinia sclerotiorum. When the upper temperature exceeded 15 ℃, the growth of the bacteria was inhibited and the disease stopped.

[prevention and control methods] after the cold-proof soil, 500-fold carbendazim was used to disinfect the border, operation road and around the ground, often dredge the working road, dig drainage ditches, loosen the soil to cool down, strengthen field quarantine, find and pull out diseased plants in time, and spray with 400-600 times of carbendazim and 150 times of polyantimycin.

Rat and bird pest

[hazard characteristics] there are mainly pests such as ground tigers, grubs, golden needles and mole crickets, as well as rats and birds biting seedlings, stems and roots, tits and face mice eat fruits and seeds, and moles and voles eat ginseng roots as caves.

[control methods] include killing or baiting pests, raising cats to hunt mice, and using grass men, colorful flags, cannons, etc., to expel pests.

Integrated prevention and cure

The main results are as follows: 1. There should be more than 2-3 years of rotation or leisure.

2. Where corn, potatoes and vegetables have been planted, American ginseng cannot be planted.

3. The soil should be weathered and decomposed and fumigated.

4. Clean and disinfect the working path and the surface of the reference bed every winter. Sulfur powder or cupric sulfate solution can be used to sterilize the working road to prevent man-made transmission of diseases.

5. When the seeds are stored in sand to raise embryos, the seeds are mixed with 0.3% of the seed weight, and the seeds should be properly turned and dried every 1 to 2 months to prevent bacterial contamination.

6. the above-ground diseases are mainly prevented and treated by spraying. The United States has been spraying medicine every 7-10 days since late May, with a total of 12-15 times during the whole growing period. China should pay attention to the principle that prevention is more important than cure.