Prevention and Control of Leaf Blight of Anthrax from Apple

First, the symptoms

At the time of initial onset, there are multiple dry and blight spots on the leaves. The lesions are brown at the beginning. In the conditions of high temperature and high humidity, the lesions spread rapidly and can spread to the entire leaf within 1 to 2 days. The results can be reached in 2 to 3 days. The leaves of the tree are dry and fall off, and the dead leaves are dark in color, mostly dark brown, as if burnt with water. When the environmental conditions are unsuitable, dead and dead patches of varying sizes are formed on the leaves. The healthy tissue around the lesion then turns yellow and the diseased leaves quickly fall off. When the lesions are small and numerous, the diseased leaves resemble the symptoms of brown spot disease. A number of round brown depressions with a diameter of 2 to 3 mm appeared on the fruit surface of the victim fruit. The fruit surface around the lesion was red, and the pulp under the lesion was brownish sponge-like, with a depth of about 2 mm. The lesions on the fruit under natural conditions were very Less sporulated, obviously different from the common apple anthrax symptoms.

Second, prevention and control technology

1. Stop germs from spreading. Strengthen plant quarantine and ban the transfer of scion, seedlings, and diseased fruit from the diseased orchard to prevent the spread of germs.

2. Eradicate overwintering germs. For the diseased orchard, 100-200 times of copper sulphate solution can be sprayed in October. Before the budding of the apple in April of the next year, 100-200 times of copper sulphate solution or other strong killing agent can be sprayed again. , eradicate the wintering germs on shoots and dormant buds.

3. Regular spraying protection. Strengthen publicity and training, so that farmers can change their mistaken understanding of “not seeing diseases and not spraying”. From the beginning of May onwards, spraying Bordeaux mixture and sedatives alternately, every 10 to 15 days, to ensure that each time there is more than 2 days of continuous rain, leaves and branches are in the protection of the pharmaceutical.

4. Advance or spray the medicine. During the rainy season from July to September, according to the weather forecast, if there is continuous rainy weather around 7 days after the last spraying, it is necessary to spray protection before the rain. If the spray is not sprayed in time before the rain, it is necessary to make up during the continuous rainy interval. Mancozeb or Bordeaux mixture.

5. Pay attention to the quality of medicines and sprays. The quality of the drugs used by the regular enterprises for production and sales shall be selected. The spraying shall be meticulous and thorough, and the branches shall be sprayed. In particular, the internal branches of the crown shall be sprayed. The front, back and fruits of the leaves shall be ensured to be evenly coated. At the same time, the higher the atomization degree of the liquid medicine, the better the control effect.

6. Strengthen agricultural control. Before the onset of the rainy season, it is necessary to refurbish the drainage facilities to ensure the timely removal of water from the orchard. Closed orchards should be strengthened in the summer to improve the ventilation and light conditions. After the occurrence of the disease, the leaves should be removed in time and brought out of the garden for sterilization. The tree body should be sprayed and sterilized. Remove the disease early to avoid excessive consumption of tree nutrients. We will strengthen the management of intertillage and fertilization, improve the quality of flower buds, and strive to maintain high yields in the coming year.