The Pathogen and Control of Nectarine Root Cancer

Peach root cancer, also known as crown gall disease, is a widespread plant disease caused by the bacterium *Agrobacterium tumefaciens*. This pathogen affects a broad range of host plants, including over 1,193 species across 138 families such as peaches, pears, apples, grapes, persimmons, plums, cherries, chestnuts, walnuts, jujubes, and chrysanthemums. The disease typically infects the roots and lower trunk of the host plant, forming galls that weaken the tree's structure. In severe cases, it can lead to the death of fruit trees. The bacterium *A. tumefaciens* is a short, rod-shaped, flagellated organism without spores. It thrives best at 22°C, with a temperature range from 10°C to 34°C, and is killed within 10 minutes at 51°C. Its optimal pH is around 7.3. In the 1970s, Australian researcher Professor Kerr identified three biochemical types, with peach trees commonly infected by type I and II. Cancerous growths usually appear on the root neck and main roots, forming round or irregularly shaped tumors. These can be as small as a bean or as large as a fist, sometimes growing in clusters. Tumors are smooth on the surface, ranging in color from milky white to dark brown, and have a hard, rough texture. As they mature, they may crack, rot, and emit an unpleasant odor. New secondary tumors can develop around old ones, further weakening the tree. The disease spreads through rainwater, irrigation, soil-dwelling pests, nematodes, and infected seedlings. Entry points include wounds from grafting, insects, or mechanical damage. Once inside, the bacteria trigger uncontrolled cell division, leading to tumor formation. The time it takes for symptoms to appear varies widely, from weeks to over a year. Heavy infestations are common in orchards and nurseries, especially in areas where peaches or poplars are grown. Alkaline soils, high moisture, clayey texture, and poor drainage all favor infection. To manage the disease, several strategies are recommended: (1) Use high-quality, disease-free seedlings and avoid planting in previously infected areas. Grafted seedlings should be kept off the ground, and tools must be disinfected with 75% alcohol before and after use. Acidic fertilizers or organic matter can help adjust soil pH to make it less favorable for bacterial growth. (2) Inspect seedlings carefully before planting. Diseased seedlings can be treated with K84 biological pesticide (diluted 30–50 times), 3% sodium hypochlorite, or 1% copper sulfate solution. After treatment, they should be dipped in 2% lime water. These methods are also effective for soaking peach seeds to prevent infection. (3) For existing tumors, remove them with a clean knife and disinfect the wound using diluted copper sulfate or antibacterial agent-402. Apply Bordeaux paste or 1000x streptomycin solution mixed with Vaseline for protection. Alternatively, a mixture of 5° Baumé lime sulfur and lard can be used. All removed tumors should be burned immediately. The surrounding soil can be treated with a 2000x dilution of antibacterial agent-402. Avoid leaving the wound exposed for more than a week, as this can lead to tree death.

Pro Xylane Ingredients

Pro Xylane In Skincare,Pro Xylane,Xylane,Pro Xylane For Skin

Zhengzhou Bridge Biochem Co.,Ltd. , https://www.biochemfeeds.com