In the growing season, frequent visits to orchards and finding diseased leaves and other diseased tissues can enlarge the cut parts and avoid the latent spread of germs. When operating, you can carry a small basket, take the cut diseased tissues out of the orchard and burn them centrally. After the grapes are harvested, clean the dried fruits and ears on the ground, burn them or bury them deeply. Leaves fall in autumn, and after pruning in winter, wash them again. Keep the floor clean. It is best to carry out deep tillage to eliminate the source of overwintering bacteria.
2. Strengthen the management of cutting and pruning, and optimize the orchard environment.
(1) Avoid choosing cohesive soil and low concave land when building the garden, appropriately relax the row spacing, try to make the row direction parallel to the wind direction, appropriately increase the height of scaffolding, enhance the ventilation and light transmission conditions in the garden, and reduce the occurrence of diseases.
② When pruning in winter and summer, the density of branches and vines should be fully considered. Pruning should be reasonable, the spacing between new branches on the shelf surface should be kept at 65,438 0.5 cm, and unnecessary branches and leaves near the ground should be removed as much as possible to reduce the chance of bacterial infection. Scaffolding is more likely to induce this disease than hedges. Timely pruning, timely breaking of secondary branches, core removal, removal of long branches, to prevent the branches and leaves from being too crowded, so that the branches and leaves and fruits maintain an appropriate proportion.
(3) Enhance tree vigor and improve disease resistance. Sufficient high-quality decomposed base fertilizer and appropriate application of phosphorus and potassium fertilizer in acidic topsoil.
More lime should be applied to improve the resistance of trees to downy mildew. In southern China, applying lime to the ground or spraying 1 %~3% calcium superphosphate on the leaves can increase the disease resistance of plants.
(4) Do a good job of irrigation and drainage in the orchard to reduce the humidity in the field. Orchards are damp and prone to diseases.
⑤ Drip-free defogging film is used as the covering material outside the facility, and the whole area of the facility is covered with plastic film to reduce the air humidity, prevent the occurrence of fog, and inhibit the formation and germination of sporangium and the germination and infection of zoospores.
⑥ Adjust the indoor temperature and humidity, especially after grape fruit setting, and quickly raise the room temperature to above 30℃ during the day and try to keep it at 32-35℃ to inhibit the formation and germination of sporangium and spore germination and infection under the conditions of high temperature and low humidity. At about 16 in the afternoon, open the tuyere for ventilation and dehumidification to reduce the indoor humidity, and keep the night temperature at 10- 15℃ and the air humidity not higher than 85%. Lower temperature and humidity inhibit the germination of sporangia and spores and control the occurrence of diseases.
⑦ Bagging ears to eliminate bacterial infection on ears.
(8) Selecting disease-resistant varieties.
3. Strengthen quarantine
Seedlings or cuttings introduced from other places shall be quarantined and disinfected, and shall not be introduced from epidemic areas.
4, spray protection
Spraying 1 times of 3~6 Baume lime-sulfur mixture on plants and nearby ground before burying in winter can eliminate a large number of overwintering bacteria sources. Before germination, carefully spray the ground and plants with 3-50be stone sulfur mixture+100 times of sodium pentachlorophenol solution to eradicate pathogenic bacteria in the facility. After germination, carefully spray 1 times of bactericidal protective agent every 10 day, or ignite a disinfectant smoke bomb or fumigant. Spraying 0.6% lime with half a volume of Bordeaux solution or 65% zineb with 400-500 times of solution before or at the beginning of the disease, spraying/kloc-0 once every half a month and spraying continuously for 2-3 times can effectively control downy mildew. Because bacteria invade from the stomata on the back of leaves, the focus of spraying is on the back of leaves. This is an effective experience to prevent downy mildew, and it can also save money, especially for the development of pollution-free grapes. This experience is worth learning from fruit farmers.
5. Spraying treatment
Immediately after onset, spray with 600 times solution of 50% Daphne manganese zinc. After application, the toxin mold immediately enters the plant and is transported to all parts with water to kill bacteria. Mancozeb remains on the surface, which prevents the invasion of bacteria and plays a protective role, especially at the peak of infection. At the same time, manganese and zinc are essential elements for grape physiology. However, excessive spraying or long-term use every year will produce drug resistance, so it should be used in conjunction with other protective agents, 2-3 times a year. You can also use a small amount of Bordeaux solution 200-240 times, or 27. 12% copper expensive suspension (300-400 times), or 30% Ludebao wettable powder (300 times), or green milk copper (800 times). The above liquid medicine should be mixed with 80% glyphosate wettable powder (500 times liquid), 72% Kelv wettable powder (700 times liquid), 75% chlorothalonil wettable powder (700 times liquid), 64% antiviral alum wettable powder (500 times liquid), 78% Cobo wettable powder (500 times liquid), 72.2% thorn (700 times liquid). Or alternatively used with Kelv smoke bomb, Keshuangling smoke bomb and chlorothalonil smoke agent. Note that when using drugs, the same variety of drugs should not be used continuously to avoid drug resistance. In order to improve the stress resistance, control effect and yield of grapes, the drought and flood harvest of "Tianda -2 1 16" or 1000 times can be increased when non-alkaline pesticides are sprayed.
Control methods of grape downy mildew
This disease is one of the main diseases in grape producing areas in China, and it is also common in Shanghai. Epidemic year, diseased leaves
The withered coke falls early, the diseased tip is twisted and the growth is poor, which seriously affects the tree potential, yield and quality.
【 Hazard symptom 】 Grape downy mildew mainly harms grape leaves, shoots and young fruits. leaf
When the movie was finished. The original yellow-green oil spots on the surface gradually expanded into yellow-green to brown polygonal lesions.
. When wet, a white frosty mildew layer is produced on the back of the lesion. Sick leaves become brittle and easy to dry up and fall off. When buds appear, they appear.
The translucent spots of water stains turn brown later, and a white mold layer is also produced on the surface of the diseased spots, and the growth of the diseased tip is stagnant and distorted.
In severe cases, you will die. The young fruit dies, the diseased part fades, hardens and sinks, producing a white mold layer, and then shrinks and falls off.
The fruit is damaged when it expands, brown and soft, and soon shrinks and falls off. The fruit is no longer infected after coloring. Hua Leishou
After being damaged, it becomes dark brown, and the surface is covered with white mold, which withers and falls off.
【 Pathogenic law 】 The pathogen overwinters in the diseased tissues with oospores or in the soil with diseased leaves. time
In May 2008, the egg germinated to produce blastocysts, and then the blastocysts produced swimming spores, which spread to the host leaves through wind and rain.
In fact, it invades through pores. Generally, leaves near the ground are the first to be infected. It took 10 days after the pathogen invaded the host.
About the incubation period, reinfection. If the environmental conditions are suitable, bacteria can persist throughout the grape growth period.
Produce sporangia and repeatedly infect.
In Shanghai, the disease usually begins in late May, and the peak period is August -65438+ 10, which can make grapes strict.
Early serious defoliation. The occurrence of diseases is related to temperature, humidity and rainfall. Oospores can not only germinate in leaf water droplets,
It can also germinate in wet soil. The germination and invasion of sporangia and zoospores need rain and dew. Spores germinate the most
The optimum temperature is 10- 15℃, the lowest is 5℃, and the highest is 2 1℃. Therefore, low temperature, rainy weather and high temperature in autumn are easy to cause disease flow.
All right. Orchards are low-lying and poorly ventilated, which is conducive to diseases. The grapes in the trellis are light, but the grapes in the fence are heavy in cure a disease. grape
Grape plants with more calcium have stronger disease resistance. Generally, the ratio of calcium to potassium in old leaves is large and the ratio of young leaves is strong.
Small and easy to get sick.
[Control Method]
(1) Strengthen orchard management. Collect diseased leaves and fruits in late autumn, cut off diseased branches, burn or bury them deeply. Sweep leaves
Our work should be carried out before the dew is dry in the morning, and the leaves are not easy to break. In winter, the garden is deeply turned over and buried in the ground.
Organization. Pay attention to drainage and summer pruning during growth; Hedge racks should raise the results to more than 60 cm as much as possible.
Cut off unnecessary branches and vines that are too close to the ground to reduce the humidity of the ground and reduce the incidence. Control the amount of nitrogen fertilizer in the second half of the year, increase
Applying phosphorus and potassium fertilizer can promote the senescence of branches and leaves and improve the disease resistance of plants. For varieties with strong vitality, scaffolding should be used, or
The shape of "high, wide and vertical" is used to alleviate the growth potential of branches and vines and improve the ventilation and light transmission conditions.
(2) Spraying control. Spraying 750 times of 50% toxic mildew wettable powder 1 time, with an interval of 20-30 days; Or 40%
Meiyijing wettable powder 300 times solution, sprayed every 15 days/time, has excellent control effect on grape downy mildew.
Bordeaux mixture also has a good effect on preventing downy mildew. It can also be protected with bordeaux mixture in the early stage and mildewed after the onset.
Network control. In addition, 400-500 times of 50% thiram wettable powder or 500% G4% antiviral alum wettable powder is used externally.
Spraying 58% Daphne manganese zinc wettable powder with double solution or 500 times solution is effective.