CATDOLL : CATDOLL: Please help! What pests and diseases caused this diseased branch?

1. Please help! What pests and diseases caused these diseased branches?

Reply to Feng Xing Man Xiu's post Hello friend! Teacher Zhang Xianjue has helped answer this question! Zhang Xianjue 2011-6-3 22:42 This bacterial wilt is a bacterial disease that likes high temperature and high humidity. It can be controlled by applying Bordeaux mixture or methoxyfop wettable powder:handshake I hope it helps you too!:handshake

2. Teacher, what disease is this?

Viral diseases, unreasonable fertilizer and water, large temperature differences, poisonous seeds, high temperature and drought are the main causes of the disease. At the same time, because the disease is highly contagious, if a small amount occurs, it is best to pull out and bury it deeply. It is best to change the location when replanting. The selection of agents can start from three aspects. First, virus inhibitors + regulators. Second, supplement zinc fertilizer and strengthen water and fertilizer management. Third, for pests such as aphids, you can refer to the following agents. For viral diseases, Ningnanmycin or amino oligosaccharides or Lentinan or copper morpholine acetate or chlorpyrifos or Ata Ling or Huatuo + Brassinolide or Bihu or seaweed essence + imidacloprid or acetamiprid or nipyram pymetrozine + zinc sulfate. Finally, for agricultural operations (topping, stubble wiping), try to manage the healthy plants first and the diseased plants together at the end. It is best to rotate and not repeat the same crops.

3. What are the main diseases and pests of chrysanthemum? How to prevent and control them?

1. Downy mildew: Downy mildew mainly harms leaves. When the disease occurs, faded spots appear on the leaves. As the spores multiply and grow, the leaves gradually turn yellow and lose their green color. Finally, a white mold layer appears on the spots on the back of the leaves, just like frost in winter, hence the name downy mildew.

Prevention and control methods: Before planting, collect the diseased and damaged parts in the planting area and burn them. Then deep plow the soil to prevent the bacteria from overwintering. Strengthen management during planting, increase the application of phosphorus and potassium fertilizers to increase the disease resistance of the plants. When the disease occurs, spray 250 times diluted wettable powder of frostbite-ethyl for prevention and control.

2. Leaf spot disease: It mainly harms the leaves, and irregular spots appear after the disease occurs. There are also ring patterns in the spots. As the disease progresses, the spots gradually change color to brown. In addition, they spread from the leaves to the stems and petioles, causing the plants to wither.

Prevention and control methods: Rotate with other crops, avoid continuous cropping, choose well-drained plots for planting, apply more phosphorus and potassium fertilizers during planting to increase the disease resistance of the plants, and remove the diseased leaves in time when diseased plants are found. When the disease occurs, spray 200 times dilution of Wuyimycin aqueous solution or 6.5% forbactam powder for prevention and control.

3. Aphids: Aphids suck the leaves, twigs, flower buds and other tender parts of the plant clean, causing the leaves to shrink, curl and become deformed. If the aphid infestation is severe, the entire plant will wither or even die.

Prevention and control methods: Burn weeds and debris in the field before wintering to prevent insect eggs from overwintering. Use natural enemies for prevention and control, or spray diluted aphid and mite clear emulsifiable concentrate for prevention and control.

Additional information:

Field management of chrysanthemum:

Temperature: The optimum temperature for Chrysanthemum chrysanthemum is 17~20℃. The weather is still relatively cool during early spring sowing, and there is a cold snap. Therefore, after sowing, the ground film or old greenhouse film needs to be covered on the surface of the bed, and the soil needs to be compacted around to prevent cold and keep warm. When the weather warms up, the film should be uncovered before the seedlings emerge from the soil. When the temperature in the protected field exceeds 25℃, the vents should be opened to let in air.

Thinning and weeding: When the seedlings grow to about 10 cm, thin out the small-leaf varieties at a spacing of 3 to 5 cm per plant and row, and thin out the large-leaf varieties at a spacing of about 20 cm per plant, and remove weeds at the same time.

Watering and fertilization: Start watering after the seedlings emerge from the soil. The watering time and frequency should be flexibly controlled to keep the soil moist. Apply quick-acting nitrogen fertilizer once 10 to 15 days before each harvest, 15 kg of potassium nitrate and about 8 kg of urea per mu.

4. How to calculate the probability of increasing the yield of pickerel grass

Now it takes 4-5 more flowers to increase the production. 2-3 more flowers after using the lucky potion

5. How to solve this disease and pest, please help me! ! !

The insecticide dimethoate can be used to kill them, but you must be careful when using the pesticide, as dimethoate is also toxic to humans. This is a caterpillar commonly known as the tangerine peel.

6. Teachers, please see what disease this is.

Tomato bacterial spot

Also known as tomato bacterial brown spot, tomato bacterial microspot, and bacterial leaf spot.

The main damage is to leaves, stems, flowers, petioles and fruits. Infected leaves may produce dark brown to black spots, often surrounded by yellow halos.

Prevention and control: In the early stage of the disease, you can use chlorpyrifos, thiabendazim, copper chloramine, copper hydroxide and other sprays alternately for prevention and control, spray once every 7-10 days, and spray 3 to 4 times in a row.

The above suggestions are for reference only, I hope they are useful to you.