Root rot in fruit trees is a common disease that typically occurs during the early stages of spring when tree roots begin to grow. This condition is primarily caused by the presence of various *Fusarium* species in the soil, which attack the root system. Orchards that are poorly managed—such as those with inadequate weed control, excessive use of chemical fertilizers, and insufficient organic matter—tend to suffer from higher infection rates. Additionally, orchards experiencing drought, nutrient deficiencies, soil salinization, or compaction are more prone to this disease.
Identifying the symptoms of root rot is crucial for timely intervention. Infected fruit trees usually show signs starting from the fibrous roots, where reddish-brown circular spots appear around the base of the roots. These lesions can expand and deepen over time, eventually reaching the xylem, leading to darkening and death of the entire root system. As a result, the upper parts of the tree may exhibit stunted growth, yellowing leaves, and drooping branches. These symptoms often resemble water or nutrient deficiency, but they are actually caused by bacterial infections in the root system.
To manage root rot effectively, several strategies should be implemented. First, improve orchard management by regularly pruning trees, controlling pests, and removing weeds promptly. Second, enhance soil fertility by increasing the use of organic fertilizers, which helps improve soil structure, drainage, and overall health. Third, chemical treatments can be applied in early spring or after harvest. A mixture of 800 times diluted Green Hen No. 1 or a combination of Green Hunter No. 1 and thiram (in a 1:9 ratio) can be used. Apply approximately 20–30 kg of solution per tree to ensure effective coverage and protection against the pathogen.
By combining good cultural practices with targeted chemical treatments, growers can significantly reduce the impact of root rot and maintain healthier, more productive orchards.
Biopolyols
Polyols are a group of alcohols that contain two or more hydroxyl groups in their molecules. The general formula is CnH2n+2-x(OH)x(x≥2). Polyols are generally soluble in water. Most polyols are viscous liquids or crystalline solids with high boiling points, strong solubility in polar substances, low toxicity and volatility. The boiling point, viscosity, relative density and melting point increase with the increase of molecular weight.
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