Many people say that pea downy mildew must be prevented, what measures should be taken?

Initially produces yellowish near-round or polygonal angular spots on the leaves, centimeters in size. When wet, white downy mildew grows on the dorsal lesions of the leaves, sometimes spreading to the front of the leaves. In the later stage, the lesions die and become yellow-brown, and when there are many lesions, they can be connected into patches, resulting in the drying of the whole leaf.

Lettuce downy mildew can occur in the process of lettuce planting, mainly harming the leaves of the plant, and developing from the base upward. Seedling stage disease, the leaves will turn yellow and gradually die, the adult stage is damaged, the initial leaves will appear light yellow, nearly round or polygonal lesions, when the air is humid, often encounter downy mildew as a damage lettuce growth, growers do not know how to deal with it; In this regard, we focus on the harm process of lettuce downy mildew to make a specific analysis, hoping to clarify the doubts of growers who have this demand.

<> soybean seedlings, adult leaves, pods and bean grains can be diseased. At the onset of the seedling stage, there are no symptoms of cotyledons, and the true leaves begin to appear greenish patches from the base, extending along the main vein and branch veins until the whole leaf fades green. Later, the same symptoms appeared on all leaves of the whole plant.

When soybean downy mildew damages the leaves (from the seedlings can be harmed), there will be some small patches, in the case of seedlings, the color is relatively light (similar to greening), which will expand with the main vein and side veins, and in severe cases, the whole leaf will fade green.

In the early stage of the disease, the whole field spray is commonly used in the form of methalene, manganese-zinc, manganese-zinc, manganese-zinc, manganese-zinc, manganese-zinc. When spraying, it must be noted that the two sides of the front and back of the leaf should be sprayed and sprayed evenly. After the rainy weather, it suddenly turns sunny and the ground is humid, and the hidden germs at this time can easily spread with the wind and infect the leaves.

Downy mildew and gray mold have a common feature in that they infect young branches and leaves first. Because the resistance of young branches and leaves is weak, it is easy for germs to invade.

Grape downy mildew mainly damages leaves, but can also infect young tissues such as young shoots. The leaves are damaged, and at the beginning of the leaves, translucent oil-stained small yellowish spots are produced on the front of the leaves, the edges are not obvious, and then gradually turn into pale green to yellowish brown polygonal spots, and then turn yellow and die.

It can be used with 400 times of 70% manganese wettable powder, 500 times of 72% grammycin wettable powder, or 600 800 times of 72% gram wettable powder, which can be effectively prevented and controlled.

When the melon vine grows to 2 meters, remove the main vine growth point to grow 3-4 branches. In order to create a good light transmission and ventilation conditions for the pumpkin, it is necessary to build a scaffolding, and the specific method is: when the branch vine grows to 2 meters, the vine is led to the scaffolding, and the vine is not broken.

The pumpkin after the scaffolding will reduce pests and diseases, so that the melon sitting rate will be greatly improved.

1) Choose disease-resistant varieties and keep seeds from disease-free areas. (2) Implement crop rotation for more than 2 years. (3) Clear the countryside, burn the sick and remnants in a concentrated manner, and plough the land in time. (4) Fertilize according to the formula and plant reasonably densely.

Prevention and control methods:

1. Agricultural measures: keep seeds from disease-free land and implement crop rotation for more than 2 years. Clean the farmland, collect the sick and residual bodies and burn them in a centralized manner, plough the land, carry out formula fertilization, and plant reasonably densely.

2. Pesticide control: use 35 methamethoxin seed dressing agent according to the weight of the seeds. Spray 1:1 at the beginning of the disease

1:200 times Bordeaux liquid, or 90 aluminum triacetylphosphate wettable powder 500 times liquid, or 70 Baidorfu wettable powder 500 600 times liquid, or 65 Baodasen 800 times liquid, or downy mildew carb water agent 600 times liquid, or 78% Kebo wettable powder 500 times liquid, or 56% downy mildew clear wettable powder 700 times liquid, or 69% Anker manganese zinc wettable powder 600 times liquid, or 50% methyl copper wettable powder 600 times liquid, or 90% 500 times of Physalin WP, or 400 times of 70% manganese wettable powder, 500 times of 72% Clomycin WP, or 600 800 times of 72% Kelu WP, or 60 0 times of 72% of Anti-Ling WP, or 1500 times of 50% Anker WP, or 58% of Methyl Frost & Manganese Zinc WP 500 times, 600 times of downy mildew water agent, 1500 times of inhibitory fast net (oxazole ketone and cyanide frosturea) water dispersible granules, or 64 500 times liquid of alum wettable powder and other agents, every 10 days or so l times, prevention and control 1 2 times.

For reference, thank you for your attention.

You're working well! Have fun!

To avoid resistance, alternate use.

It's all working well.

Carbendazim is a protective agent that can be sprayed to prevent disease before the disease develops.

This is not within the scope of today's answer, but you can ask a separate question.

Downy mildew control can be discussed.

The dosage varies from time to time.

At the beginning of the disease, spray 1:1:200 times Bordeaux liquid or 90% aluminum triethylphosphonate wettable powder 500 times, 60% chlorothalonil wettable powder 500 times, 72% gram dew or 72% frost urea manganese zinc (gram antiling) wettable powder 800 1000 times solution.

In areas that are resistant to the above-mentioned fungicides, 69% Anker manganese-zinc wettable powder or water-dispersible granules can be used 1000 times of liquid, once every 10 days or so, and 1 or 2 times for prevention and control.

Strengthen field management at the peak of the disease, clean the field, eradicate weeds, reduce pathogens, and uproot serious diseased plants as soon as possible; Chemical control: 25% methalene wettable powder can be used for seed dressing, and 72% frost urea and manganese zinc wettable powder 800 1000 times liquid? Downy mildew carb hydrochloride aqueous agent 700 1000 times liquid?

1000 times of 69% mancozeb and enoylmorpholine wettable powder, choose one of them for control.

You're welcome, if you don't understand something, please consult**.

You. Good.

Prevention and control methods:Due to the fast infection and long incubation period of pea gray mold, and the easy development of drug resistance, the comprehensive control measures combining ecological control, agricultural control and chemical control are mainly implemented.

1) Ecological prevention and control, sheds around the reduction of humidity. It is necessary to increase the night temperature of the shed and increase the ventilation time during the day, so as to reduce the humidity and condensation duration in the shed, so as to achieve the purpose of disease control.

2) Remove the diseased plants in time, and bury them or burn them in a centralized manner.

3) When the diseased plants are found, they will start to spray 1500 2000 times of 50% Suklin WP or 1000 1500 times of 50% Nonglilin WP, 1000 times of 50% promehanine wettable powder, 4000 times of 45% Tekel multi-suspension and 600 times of 50% mixed sulfur suspension. Once every 7 10 days, 2 3 times depending on the condition. In areas where the above-mentioned fungicides are resistant, 1500 times of 65% methamethamine wettable powder or 1000 times of 50% carbendazim (carbendazim plus vanmycolin) wettable powder can be used.

Pay attention to rotation and alternate medication to delay the emergence of drug resistance.

This is a pea virus disease.

Prevention and control methods:##41;Choose disease-resistant varieties such as inner soft No. 1 peas. & ##41;Reasonable planning for planting in patches, due to the large number of toxic crops in the near-effect vegetable area, the area is large, and the disease is serious. In particular, the disease is more serious in small areas, and it is advocated to develop to the suburbs, and the planting is concentrated in patches, which has an obvious effect of avoiding diseases.

##41;Choose high-yield and high-quality varieties. & ##41;Sow seeds at the right time to cultivate strong seedlings. It is beneficial for pea seedlings to grow robustly.

##41;Interplanted with garlic, it has an obvious effect on avoiding aphids and preventing diseases. & ##41;Early treatment of aphid disease prevention and seedling, production should be based on the weather, seedlings, insects in the first true leaf after the growth of timely spraying, after 5 7 days after spraying 1 time, commonly used agents: 50% anti-aphid wettable powder 2000 times liquid or 20% fluoride emulsifiable concentrate 2000 times liquid.

##41;At the beginning of the disease, spray 500 times of 20% poison buster wettable powder or 1000 times of 1-5% phytolingling emulsion and 100 times of 83 anti-resistance agent, once every 10 days or so, and continue to prevent and control 3 4 times. Discontinue the drug 5 days before harvest.

For reference, please rate.