How to treat the disease of tobacco seedlings?

China is a big country in tobacco production and marketing in the world, and it is widely cultivated in the north and south provinces. In the process of cultivation, the cultivation of strong seedlings is a key part of the work, if not managed properly, diseases may occur. So, how to treat the disease of tobacco seedlings?

This depends on the emergence of tobacco seedlings what disease, disease is different, control methods are also different. Tobacco seedlings are prone to diseases such as quenching, bacterial wilt, black shank, anthracnose, common mosaic and so on.

1. Sudden collapse disease

(1) symptoms: it mainly harms tobacco seedlings, and the diseased seedlings rot in the form of brown water stains near the ground. The diseased seedlings are like scalded in boiling water, and the diseased seedlings turn dark green, wilting and rotting, and the germs spread around under humid conditions, causing tobacco seedlings to become sick.

(2) Prevention and treatment: when it is found that 25% metalaxyl wettable powder, 64% disinfectant alum wettable powder, or 75% chlorothalonil wettable powder 1000 times, or 40% ethyl phosphate aluminum wettable powder can be sprayed.

2. Bacterial wilt

The main results are as follows: (1) symptom: tobacco bacterial wilt is a vascular bundle disease, the typical symptom is wilt, most of the diseased plants wither on one side, the branch root of the diseased side turns black and rotten after pulling out, and most of the roots in the case without obvious disease are normal.

(2) Control method: 200 units of agricultural streptomycin were used to irrigate the root of 50 ml per plant, once every 10-15 days, continuously for 2-3 times, and 600 times Qingkuling irrigation root spray at the same time stem spray, root zone soil spray.

3. Black shank disease

(1) symptoms: the seedlings were infected, black spots appeared at the base of the stem, or spread from the bottom leaf along the petiole to the young stem, resulting in seedling quenching. When the humidity is high, the disease is covered with white hyphae, and the seedlings die.

(2) Prevention and treatment: the seedling bed was evenly sprayed with 58% metalaxyl manganese zinc wettable powder 500 times before transplanting. Within 1 month after transplanting, in case of sporadic disease, spray the leaf surface with high-tech 30% carbendazim 600 times solution or remove the sprinkler stem base. Or when transplanting, use 95% dimethazone 100g / mu to mix 5kg of fine soil, sprinkle the soil around the stem base of tobacco plants, and seal with soil. After transplanting or before soil cultivation, 58% metalaxyl manganese zinc and 95% dimethazone wettable powder can be sprayed 500 times.

4. Anthrax

The main results are as follows: (1) symptoms: it can occur in all growth stages of tobacco, but it is common and serious in seedling stage. Seedling leaves are covered with disease spots, which often destroy the whole tobacco seedling when it is seriously diseased. Although the seedling is not destroyed in general, the seedling growth potential is poor, and it can continue to cause damage after transplanting in the field, resulting in greater losses.

(2) Prevention and treatment: Bordeaux solution can be used for prevention before the disease. After the onset of the disease, 50% carbendan wettable powder 500 times or polyoxymycin 480 spray can be used. If the control can reach more than 90%, 50% carbendazim wettable powder 800 times, or 75% chlorothalonil wettable powder 500-800 times, or 50% Dysen zinc, 80% anthrax Fumei or 50% thiram wettable powder can be sprayed with 500 times.

5. Common mosaic disease

(1) symptoms: it can occur from seedling bed stage to field adult stage. From 20 days after transplanting to the budding stage, the disease was at its peak. After topping, the diseased plant in the field still showed an upward trend, but it mainly appeared on the tobacco branch and did not do much harm. After the seedlings were infected, the vein tissue of the new leaves became light green, showing a translucent "bright pulse disease". Under the light, the veins of the diseased leaves were very clear, and a few days later, the leaves formed yellow-green "mosaic disease".

(2) Prevention and treatment: foliar spray with (20,000 units) / (ml) Ningnanmycin; alternately sprayed 2-3 times with 0.1% sodium alginate or 0.1% zinc sulfate and 0.3% urea every 3-4 days.