Control of apple blight

In spring this year, the temperature in our land was lower than usual, and there were more Rain Water, which caused serious apple blight. Apple blight, also known as apple blight, can damage apple fruit, the damaged fruit begins to be scalded, then brown, and the flesh is rotten. It can also damage the roots of trees, causing cortical rot. Whether the fruit or rhizome, when the humidity is high, all grow short white hairs. Individual years often occur seriously.

The pathogen of apple blight rot is multi-host, which is commonly found in apple orchards. The pathogen likes high humidity and low temperature, and only occurs when the humidity is close to 100%. When the temperature exceeds 25 ℃, the disease usually ceases to occur. In 2008, due to the rare climate of low temperature and high humidity before mid-June, the most serious apple blight in 20 years occurred. When invading the rhizome, it often spreads with irrigation water.

Prevention and control methods:

1. Phytophthora overwintered in the soil of the diseased body, so it is an important disease prevention measure to remove the diseased body, clean up the fallen fruit and remove the diseased fruit and leaves from the tree in time.

2. Because Rain Water spatter is the main mode of transmission of Phytophthora blight, the closer the fruit is to the ground, the more likely it is to be infected. The most common disease is the fruit less than 60cm from the ground, and the highest is no more than 1.5m. Proper measures such as improving the fruit position and grass laying on the ground can avoid infection and reduce the damage.

3. Improve the orchard ecological environment, eliminate stagnant water, reduce humidity, crown ventilation and light can effectively control the disease.

4. In the serious orchard, when the climate of low temperature and high humidity occurs from May to June, copper sulfate with 100 times liquid can be sprayed on the ground, whichever is wet. Spray control before bagging, with emphasis on fruits less than one meter high. Various agents can be used to control downy mildew. When invading the rhizome of the tree, 100 times the solution of copper sulfate was used to irrigate it.