The Latest Methods for Controlling Bacterial Angular Leaf Spot of Cucumber in Summer

Cucumber is a vegetable that people love to eat in summer, and this vegetable can be eaten almost all year round. Cucumbers are also the crop that farmers grow the most in their fields, and cucumber vines can generally be seen in rural areas. However, cucumbers are also a vegetable prone to relatively many pests and diseases when grown, especially in summer when the diseases are quite serious, which leaves many growers looking bewildered. So below, Shuaishuai will tell everyone how to control bacterial angular leaf spot of cucumber!

I. Conditions for Onset of the Disease

1. The pathogen of this disease likes to attach itself to cucumber seeds. This pathogen does not stir, but overwinters in the remains of diseased plants, then wakes up the following year to infect cucumbers. Moreover, its lifespan is very long, generally able to live for as long as two years. Its main modes of transmission are rain and irrigation water. After being absorbed with water by the plant, or entering the plant directly through stomata or wounds, it causes disease. It can spread a second time, and after one rain it can infect repeatedly again.

2. When cucumbers are grown in greenhouses, the air humidity inside is generally relatively high, which easily causes the pathogen to fester; the diseased ooze easily infects other parts and plants, and at the same time the resistance of the cucumber declines. If everyone does not pay attention to this disease, it will easily spread and infect repeatedly.

3. The optimal temperature for onset of the disease is between 24-28 degrees, with a maximum of 39 degrees and a minimum of 4 degrees. This pathogen is not tolerant of high temperatures; if the temperature reaches as high as fifty degrees, it will die within ten minutes. The optimal humidity is around eighty percent. If there is a lot of water on the leaves, the incidence of the disease is high. From this it can be seen that this disease is a high-temperature, high-humidity disease.

II. Control Methods

1. Because in summer the temperature can often remain above thirty degrees, this is the peak period for bacterial angular leaf spot of cucumber. This disease mainly harms the leaves and root stems. The symptoms of this disease are very similar to those of cucumber downy mildew, so when choosing control measures it brings certain difficulties. When judging, everyone must observe carefully whether it is actually downy mildew or angular leaf spot; otherwise, using the wrong method and spraying the wrong pesticide will certainly cause death and economic losses. Everyone should take measures as early as possible.

2. When selecting seedlings, try as much as possible to choose seedling varieties with strong disease resistance; this is something that can be done when selecting seeds.

3. When collecting seeds, choose healthy varieties without disease, so that the seeds cultivated will be excellent.

4. Before sowing, the seeds need to first be placed in a 70-degree constant-temperature chamber for three days to sterilize them, then soaked in 50-degree warm water, and only after that can they be taken out, dried, and sown.

5. Heavily diseased fields should undergo crop rotation for more than 2 years. During the growing period, diseased leaves and diseased plants should be promptly cleaned up to avoid secondary infection. The cleared material can be directly buried deep or burned.

The above are the methods for controlling bacterial angular leaf spot of cucumber in summer. Has everyone learned them? In ordinary times, everyone should observe more and try to take corresponding measures promptly at the early stage of the disease. In ordinary times, prevention and control management should be strengthened, so that infection can be avoided.