What reason is cucumber sudden fall disease? How to treat it?

Cucumber sudden fall disease, commonly known as "neck jam", "small foot blast", "seedling drop" and so on, is one of the common diseases in cucumber seedling stage in winter and spring. The quenching disease mainly occurred after the emergence of the seedling bed, and flooded spots appeared at the base or middle of the embryo stem near the ground in the seedling stage, gradually turned yellowish brown in the later stage, and shrunk into a linear fold around the stem, the disease center was obvious, what is the cause of cucumber quenching disease? How to treat it?

First, what is the cause of cucumber sudden fall disease?

Because the suitable ground temperature for the growth of the pathogen is 15-16 ℃, and the growth of the pathogen will be inhibited when the temperature is higher than 30 ℃, the suitable ground temperature for cucumber stunting disease is about 10 ℃, which is disadvantageous to the growth of cucumber, but the pathogen can move, especially in the seedling stage under the condition of low temperature and high humidity.

There is a susceptible period before the cotyledons of the seedlings are basically consumed and the new roots are not firm. At this time, the true leaves are not extracted, carbohydrates can not be accumulated rapidly, and the disease resistance is weak. If the rain, snow and cloudy days or cold currents attack, the ground temperature decreases and the photosynthesis is weak. In this case, the respiration of cucumber seedlings is enhanced, and the consumption of photosynthetic products (mainly carbohydrates) is increased. As a result, the young stem cells of cucumber seedlings elongated and the cell wall became thinner and vulnerable to bacteria.

Therefore, cucumber quenching disease is easy to occur when cucumber seedlings grow 1 or 2 true leaves, and when 3 true leaves grow, the incidence will be greatly reduced.

Second, how to treat cucumber quenching disease?

1. Seed selection is the key.

Yuanfengyuan 6 cucumber, Zhongnong 7, Yuexiu 1, Zaoqing 2 and Zhongnong 8 can be selected.

2. Seeds should be disinfected.

The seeds can be soaked in 50 ℃ warm water for 20 minutes, or sterilized by 70 ℃ dry heat for 72 hours and then germinated and sown. The use of cucumber seed coating agent 9-2 is recommended, and the dosage is 0.5% of the seed weight.

3. The treatment of seedling bed should be suitable.

The compost made by Japanese enzyme bacteria was applied in seedbed or greenhouse to reduce the application amount of chemical fertilizer and pesticide. If necessary, the nursery bed can renew the bed soil and apply compost made by enzyme bacteria or fully mature organic fertilizer. In production, we often choose the soil in the old vegetable garden as the bed soil. 15-20 days before sowing, mix with 40% seed powder plus 50% thiram powder at 1:1, or with 40% seed powder, 8 grams per square meter of seedbed, 40 kg of fine dry soil, mix well and set aside. Pour the bottom water thoroughly before sowing, and after the water seeps, sprinkle the medicinal soil mixed with 1 beat 3 on the bed surface, and then sow the seeds that speed up the budding. finally, cover the remaining 2 beat 3 medicinal soil on the seed, which is about 1 cm thick, so that the seed is sandwiched in the middle of the medicinal soil.

4. strengthen the management of seedling stage.

The temperature of nursery bed or greenhouse was kept at 25: 30 ℃ during the day and 10: 15 ℃ at night to prevent the cold current. Seedbed or shed humidity should not be too high, even rain or rain or snow weather or bed soil is not dry, should be less watering or no watering, must be watered gently with spray pot, so as to avoid excessive humidity. When there are water droplets on the plastic film or glass and seedling leaves, it is necessary to ventilate or sprinkle some plant ash to reduce moisture.

5. Chemical control

The main results are as follows: (1) the disease can be reduced by adding appropriate amount of soil additives (made of rice husk, bagasse, shrimp shell powder, silicic acid slag, etc.).

(2) using carbon dioxide fertilization technology, or applying Huimanfeng multi-component organic active liquid fertilizer, using 320ml per mu, diluted to 500 times liquid, spraying twice.

(3) 50 grams of copper sulfate and 375 grams of ammonium bicarbonate are mixed evenly, then 100 grams of hydrated lime are mixed, mixed and packed in a plastic bag to seal the mouth of the bag for 24 hours. After mixing 5 kilograms of fine soil, evenly sprinkle the seedling bed with 10 square meters, rake and hoe the seedling bed, brush off the medicinal soil on the seedling leaves, and pay attention to ventilation to remove excess ammonia.