Symptoms and control points of eggplant cotton blight

Eggplant cotton blight causes pieces of fruit to rot and fall off, which is one of the important diseases of eggplant, which is common in various places, and can be damaged in all growth stages of eggplant. The general loss is 20% to 30%, and when it is serious, it is more than 50%. The peak period of the disease is also the peak period of the disease, and disasters often occur in rainy areas and years.

First, symptoms

Cotton blight is mainly harmful to fruits, but also to stems, leaves and flowers. At the initial stage of the disease, the fruit surface was waterlogged round disease spot, slightly sunken, yellowish brown or dark brown, developed rapidly under suitable conditions, and gradually made the whole fruit surface rot. Under the condition of high humidity, the diseased part produces dense white cotton-like matter, the flesh is dark brown and rotten, and the diseased fruit is easy to fall off, or contract into a stiff fruit. Can also be harmful leaves, stems, flowers, diseased stems to form water stains, dark green or purple-brown disease spots, when the humidity is high sparse white mold. When the seedlings were killed, the base of the stem showed watery necrosis, causing quenching.

Second, the conditions of the disease.

Eggplant cotton blight is a fungal disease. It is mainly spread by soil and Rain Water. The disease is easy to occur when high temperature and humidity, sunny after rain, excessive plant density, poor ventilation and light transmission, low-lying terrain and heavy soil viscosity.

III. Comprehensive prevention and control

For the eggplant to be sown in the greenhouse in August, the following control measures can be taken:

1. Select disease-resistant varieties: general round eggplant varieties are more resistant than long eggplant varieties, such as black eggplant, nine-leaf eggplant and so on. In addition, thick-skinned varieties were more resistant than thin-skinned varieties, and early-maturing varieties were more resistant than late-maturing varieties.

2. Seed disinfection: disinfecting the seeds before sowing, such as soaking the seeds in warm water of 50 ℃ ~ 55 ℃ for 7 minutes and then sowing for 8 minutes, can greatly reduce the occurrence of cotton blight.

3. Using hole tray to raise seedlings: 288 holes with six plates and one seed per hole can be used, with sufficient nutrients, developed root system, no or less root injury during planting, enhance disease resistance and reduce the chance of infection.

4. implement crop rotation: it is necessary to arrange plots reasonably and avoid continuous cropping with tomatoes, peppers and other Solanaceae and cucurbitaceae crops. Crop rotation is generally carried out for more than 3 years.

5. Choose the place carefully. Attention should be paid to the selection of plots with high dryness and good drainage, and the use of deep ditch and high border cultivation is beneficial to drainage after rain. Try to avoid the land where the soil is heavy and easy to accumulate water after rain.

For the open field eggplant which is in the fruit setting period, the following control measures can be taken:

1. Plastic film mulching: black plastic film is used to cover the ground or spread between rows, which can block the spatter transmission of germ spores to eggplant fruit in the soil. It can also use sunlight to sterilize at high temperature and prevent the growth of weeds.

2. Scientific fertilizer and water: adequate application of mature farm manure, increase of phosphorus and potassium fertilizer, timely topdressing, small water fine irrigation without stagnant water, cold water should be poured immediately after rainstorm to resist infection and enhance plant disease resistance.

3. Fine management: pruning timely, removing the lower old leaves, improving the ventilation and light transmission conditions in the field, removing diseased leaves and fruits in time, and taking the diseased bodies out of the field to prevent re-infection.

4. Chemical control: spray the seedling bed with 50% gram carbendan wettable powder 500 times before planting. You can also use 50% carbendazim wettable powder 5 kg mixed with soil 100 kg, sprinkled into the planting hole. After slowing down the seedlings, spray the roots of the plant with 500 times of 70% Dexamethasone wettable powder or 500 times of 70% zinc wettable powder, once every 7 days.

If a central diseased plant has just appeared, it should be removed and destroyed immediately and sprayed. Spray 1 ∶ 1 ∶ Bordeaux solution every 7 days, especially before rain, to prevent diseases. Immediately after the onset of the disease, 75% chlorothalonil 500 times 600 times solution, 50% methyl thiophanate wettable powder 800 times solution, 40% ethyl phosphorus aluminum wettable powder 200 times solution, etc., alternately, generally sprayed once every 7 to 10 days, 3 times for 4 times.