Occurrence and effective control of common diseases of Pseudostellaria heterophylla

Purple feather disease of Radix Pseudostellariae is one of the common diseases of Radix Pseudostellariae, also known as mildew root, mud dragon, rotten cattail and so on. The pathogen invaded from the root system of Prince ginseng, and then spread to the thicker branch root and main root. The diseased root was yellowish brown at first, then became dark brown, and when the cortex was serious, the purple-brown mycelium could be seen on the surface of the injured root, the hyphae intertwined into a rhizomatous fungal cord, the mycelium crisscrossed with a network, the hyphae in the cord showed H-shaped connection, and the root was covered with bacteriocin. in the later stage, a layer of purplish-red velvet membrane was formed at the base of the rhizome and near the ground. The rhizome was infected with disease, the leaf surface grew slowly and small, the leaf color was yellow, the lower leaves fell off early, the tip of the leaf tip or branchlets died, and finally the whole plant died.

Occurrence regularity

The pathogen overwintered or overwintered in the diseased root and soil with bacteriocin and sclerotia. It is mainly spread by disease root contact, water flow and agricultural tools, but rarely by basidiospores. Diseased ginseng seedlings are the main way of long-distance transmission. Most of the bacteria are distributed in the range of soil 5-25cm. It belongs to good gas bacteria. The birth temperature limit is 8 ℃ and 35 ℃, and the optimum temperature is 27 ℃. When Prince ginseng fell ill, the central diseased plant first appeared and then spread in all directions. If the water source is contaminated by germs, it can cause the whole disease. Soil stagnant water or acidic, gravel soil is easy to occur. Continuous cropping or rice fields, potatoes and other susceptible crops are seriously affected. The bacteria can infect 113 species of plants in 48 families.

Prevention and cure method

Comprehensive control measures such as strengthening cultivation and management measures, improving environmental conditions, ensuring the healthy growth of Radix Pseudostellariae, reducing the number of pathogens and timely medication were taken to control the disease. Remove weeds and roots around Radix Pseudostellariae in time to reduce the source of bacteria. Scrape off the decaying tissue of the diseased plant, remove the decaying roots and destroy them.

Cultivation and management

For the soil with bacteria around the purple feather, on the one hand, thoroughly remove the residual roots, rotten roots, rotten bark and other diseased remains in the soil, on the other hand, turn the soil and dry the soil. If the conditions permit, it is best to change the soil; to increase the application of organic fertilizer to ensure the healthy growth and improve the disease resistance of Radix Pseudostellariae; to improve the aeration and drainage capacity of the soil and destroy the suitable environment of bacteria by mixing sand with clay, digging ditches and draining water; for the condition that the soil cover is too thick and affects the respiration of the root system of Radix Pseudostellariae, the topsoil should be removed properly. Strengthen the prevention and control of other diseases and insect pests, increase its ventilation and light transmission, increase the diversity of Radix Pseudostellariae, and establish a relatively balanced ecosystem, so as to improve disease resistance.

Chemical control

Pharmaceutical prevention must be early, with an interval of 6-7 days, 3-4 times in a row, and the control effect is more than 60%. The control effect was 60% when 70% pentachlorophenol sodium wettable powder was injected into the root soil, and the control effect was 60%. It could also be sprinkled around the diseased plant, that is, 40% pentachloronitrobenzene, 8 g per square meter, and 12.5% 15 kg fine soil was applied to the root of the diseased plant, with a control effect of 68%. Or directly sprinkle 70% methyl topiramate wettable powder around the diseased plant, with a control effect of 62%. Control the serious disease area and restrain the occurrence of disease.

Seriously diseased plants (generally refers to plants that died more than 1 pound 2) should be dug up in time and burned centrally, and the surrounding soil should be disinfected with 50% chloronitramine water 100 times or 40% pentachloronitrobenzene 50% 100 times poisonous soil or 70% methyl thiophanate 800 1000 times, or disinfected with lime powder, and the control effect is 60%.