A Detailed Guide to Common Cherry Blossom Diseases and Care Management Methods
1. Cherry blossom leaves are glossy, thick and green in spring, evergreen in summer, and turn red in autumn. These are all signs of vigorous growth in cherry blossoms, and they also indicate that the cherry blossom's flowering the following year will be relatively ideal.
2. ① The cherry blossom trunk shows symptoms of gummosis. This phenomenon is not a disease, but is caused by moths boring into the trunk to lay eggs. The eggs should be promptly dug out with a knife and medication injected, while also improving the soil, strengthening water and fertilizer management, and pruning rationally. ② Many mushroom-like and moss-like growths appear on the trunk. This indicates that many pathogens have invaded the branches of the cherry tree, and they should be promptly pruned off and burned in a centralized manner to reduce sources of disease and create conditions unfavorable to pathogen development.
3. By observing the cherry blossom's growth through the four seasons, if the branches and leaves are found to be sparse (leaves yellowing and dropping early, fewer flowers, short flowering period), this indicates a problem with its root system. Generally, it is "crown gall," caused by infection with Agrobacterium tumefaciens. This bacterium survives the winter within the tumor cortex or in the soil along with broken tumor remnants, spreads via rainwater and irrigation water as well as underground pests and gardening tools, and is spread over long distances via diseased seedlings. The pathogen invades the plant through various wounds. The disease is usually severe when the soil is moist, waterlogged and rich in organic matter, and alkaline soil favors its occurrence. The tumors should be promptly excised, and the soil around the diseased plant can be disinfected by scattering sulfur powder at a rate of 50 to 100 grams per sq m. Alternatively, the root collar and roots of the diseased plant can be soaked in a 500- to 1000-fold streptomycin solution for 30 minutes for disinfection. Using leaf mold, charcoal powder and microorganisms to improve the soil gives relatively good therapeutic results.
Autumn Tree Management for Cherry Blossoms
1. Disease prevention and leaf protection. Cherry blossom leaves are susceptible to infection by diseases such as powdery mildew, brown spot and sooty mold. If not controlled in time, this can cause premature leaf drop, affecting nutrient accumulation and thus being unfavorable to flowering the following year. Options include 70% thiophanate-methyl 1000-fold solution and 65% zineb wettable powder 500-fold solution, sprayed once every 15 days. Try to avoid using dichlorvos to prevent leaf drop. Water appropriately and increase foliar fertilization (0.3% to 0.5% urea, 0.3% potassium dihydrogen phosphate) to ensure the leaves are intact, thick and dark green.
2. Autumn application of base fertilizer. Base fertilizer is generally applied in early September, when the fertilizer has ample time to decompose and can be absorbed and used by the tree before dormancy. At this time, the roots cut by fertilization can heal quickly and sprout large numbers of absorbing roots, improving the tree's absorption and utilization rate of fertilizer. The fertilizer type is mainly decomposed farmyard manure, with a small amount of chemical fertilizer. Generally, young trees are given 50 to 75 kg of compost per tree. Autumn base fertilizer should not be applied too deep; 40 to 50 cm is suitable. Young trees can use the trench application method, while vigorous trees can use the broadcast application method. If nutrient deficiency symptoms are found in the tree, a small amount of trace elements can be mixed in appropriately.
3. Deep digging of the tree. Before the autumn peak of cherry blossom root growth arrives, in conjunction with the application of base fertilizer, deep digging of the tree can increase deep root mass, store water and conserve moisture, and raise soil temperature. Clean up dead branches, fallen leaves, weeds and other debris within the tree and burn them in a centralized manner to eliminate overwintering pests and pathogen sources.
4. Autumn pruning. In conjunction with the tree's growth condition, promptly thin out dense branches, crossing branches, overlapping branches and diseased or pest-infested branches to improve canopy ventilation and light penetration and strengthen tree vigor. Use a sharp knife to smooth and scrape clean the wounds, apply 5-degree lime sulfur solution for disinfection, then apply a protectant such as tung oil to prevent the wounds from rotting.