"Red oil" on the apple tree

First, the name of the disease. The disease of red oil on the apple tree is called "ulcer-type dry rot", not rot disease and rot disease. This disease not only harms the trunk, but also harms the fruit.

Second, the difference between the performance of ulcer-type dry rot and rot disease and ring-shaped rough skin disease. The pathogenic sites of 1.3 kinds of branch diseases have different degrees of brown-brown liquid overflow, which is the main reason why fruit farmers are difficult to identify and distinguish the three diseases. Differences in the appearance of 2.3 kinds of branch diseases: 1 The incidence of rot disease is earlier. In general, the lesions can be found in February and the diseased parts have obvious distiller's taste. The ulcer type dry rot is late, general year 4 ～ May disease, this year's climate is special, the incidence is earlier, and the disease organization has no distiller's taste. 2 rounds of rough skin disease can occur every year from April to August, the obvious feature is that the diseased parts of the branches are rough skin; while the ulcer type dry rot has no distiller's taste, the disease spots are dry and sag after the water is lost, and the disease and health junctions often break open. The surface of the lesion has longitudinal and transverse cracks, but no diseased protrusions are formed.

Third, the cause of ulcer-type dry rot. 1. The general year of the disease has two onset periods, the previous period is from April to May, and the later period is from September to October. The main reason for the earlier onset of this year is that: 1 the winter is less than the spring, causing severe water shortage in the trunk, and the tree body resistance is decreased, which is a predisposing factor; 2 the big cold wave and freezing damage at the beginning of the year aggravated the disease. 3) The recent rain is less, the air is dry, and the water lost from the trunk is more, which creates favorable conditions for the occurrence of the disease. These factors are the main reasons leading to the disease's earlier onset this year. 2. Winter drought, low temperature cold wave, spring drought is more likely to induce the disease. 3. The management level is low, the fertilizer and water are insufficient, the load is too heavy, the tree body is too weak, the nitrogen fertilizer is applied, the soil plate is thin, the root system is poorly developed, and the wound is more, which is the internal cause of the disease.

Fourth, prevention and control measures. This disease not only causes the onset of the stem, but also infects the fruit to cause damage. Therefore, it cannot be taken lightly and must be highly valued. The prevention and control measures are as follows: 1. Strengthen management, enhance tree potential, rationally fertilize, and improve the level of tree resistance. 2. Reasonable load, the amount of fruit hanging must be reduced for the weak tree, so that in addition to the normal physiological consumption, the tree body has sufficient resistance nutrition to balance the infection and disease of the disease. 3. Watering before freezing and early spring to increase the water content of the tree is a positive measure to prevent the disease. 4. Pay attention to the cold-proof work during the winter, and use the method of whitening the trunk to reduce the freezing damage. 5. Check and remove the lesions in time. This disease generally only harms the epidermis, should be cured in time to avoid its expansion to the less diseased garden, after scraping the lesion, 430 g / liter of tebuconazole 100 times + appropriate amount of flour into a paste to spread the lesion; For more common and serious gardens, 430 g / liter of tebuconazole 300 times liquid + silicone penetrant can be used to spray or brush the entire trunk to reduce the degree of damage.