Why does broccoli get black rot? What are the prevention and control measures?

Broccoli is a green and healthy vegetable, whether the elderly or children eat a little broccoli is good for their health. Broccoli and cauliflower are similar in shape, but the color is dark green and can be eaten with cold salad. It is also a good food for reducing fat. Broccoli is planted everywhere. Recently, some growers asked why their own broccoli got black rot. What are the prevention and control measures?

First, why does broccoli get black rot?

The pathogen of black rot can overwinter in seeds or in soil with disease residues, invading from water pores or wounds; seeds can carry bacteria, and the pathogens can survive on seeds for about 28 months, which is one of the main ways of long-distance transmission of the disease. Most of the disease begins from rosette stage to heading stage; germs spread through Rain Water, irrigation water and agricultural tools, and can be transmitted over a long distance by using infected seeds and vegetable seedlings. High temperature, high humidity and rain, leaf dew and leaf margin spitting water are all conducive to the disease; low-lying terrain, poor drainage, often flooding irrigation, planting too early, continuous cropping with cruciferous vegetables all the year round; application of unrotten organic fertilizer, partial application of nitrogen fertilizer, poor or prosperous growth, root injury during intertillage, the land with more and more insect pests is also serious, especially after rainstorm, the disease is very easy to spread.

What are the prevention and control measures for black rot of broccoli?

1. Disinfection of seedbed

Medicament can choose formalin, the method is: every square meter seedling bed with formalin 30ml mixed with water 2.55kg, then spray with sprayer (to sprinkler) spray, spray while turning the soil, spray evenly after covering the agricultural film, a week later uncover the agricultural film, turn the soil several times, let formalin evaporate fully, the time is about 5 to 7 days.

2. Seed treatment

The seeds can be soaked in a 200-fold solution of 50% Dysenamine water for 15 minutes, then washed and dried and sown. Soaking seeds in warm soup will seriously affect the germination rate of cauliflower, so you should use it with caution and try not to use it.

3. Seedbed management

If the seedling period is in summer, protective areas must be used to raise seedlings and cover sunshade nets to prevent sun exposure and rainstorm scourge. after the seedlings are unearthed, they should often check the situation of the seedlings to ensure that the seedlings are even and strong, and if there are diseased seedlings, they should be pulled out and sprayed in time to control them. At the same time, during the whole seedling raising period, it is necessary to control diseases and insect pests such as standing blight, quenching disease, vegetable green insect and so on.

4. Rotation and stubble

Rotation with non-cruciferous vegetables for more than 2 years can basically solve the problem of soil bacteria. In order to eliminate or reduce the pathogens in the soil, the soil was deeply sunburned for 10 to 20 days before planting, so as to speed up the ripening of plant residues and the death of bacteria in the soil.

5. Ploughing and weeding

In order to plant and slow down seedlings, sufficient seedling fertilizer should be applied, fertilizer and water management should be strengthened during plant growth, and calcium-boron-silicon fertilizer should be applied in sufficient amount to strengthen the resistance of the body, prevent premature senescence and enhance its disease resistance. Irrigation must avoid flooding, so as to reduce the chance of germs spreading. According to soil moisture, ploughing and weeding is carried out in time.

6. Pest control

In addition to causing direct losses, insect pests also provide pathogens with ways to infect from wounds, so black rot is also serious in plots with many insect pests, so it is necessary to control pests first to prevent diseases, especially the harm of cabbage insects and Plutella xylostella. Timely control of Plutella xylostella, Pieris rapae, Spodoptera exigua, ape leaf beetle, maggot and other pests to prevent them from spreading the disease.

7. Prevent and cure diseases

After the occurrence of the diseased plant in the center of black rot in the field, it should be controlled in time. The control agent can use 50% Dysenamine 500 times solution, and 200 mg / kg of agricultural streptomycin, streptomycin sulfate, neophytomycin, etc., which has obvious control effect. In addition, 50% methyl topiramate and 50% carbendazim wettable powder are also very effective.