What pesticides work well for growing napa cabbage
Napa cabbage is a common vegetable in daily life, almost every household grows it, and it is very popular in the market. But during the cultivation of napa cabbage, various pests and diseases appear. So what pesticides are used to control napa cabbage?
1. Cabbage damping-off disease
Damping-off disease is common on various vegetables and harms seedlings. When it occurs, water-soaked lesions appear at the base of the seedling stem, gradually constrict into a thread as the disease progresses, and then the seedling bends and falls to the ground. If the soil moisture is high, white cotton-like material also appears at the site of infection.
Control method: This disease mainly appears in the high-temperature rainy season in the south, and is also prone to occur in low-temperature and high-humidity environments during the seedling stage. Disinfect seeds and soil before planting, and after the disease occurs, spray with propamocarb hydrochloride or metalaxyl + hymexazol for control.
2. Cabbage black rot
Black rot can occur on both cabbage seedlings and mature plants. When seedlings are affected, water-soaked lesions appear on the leaves, the roots turn black, and finally the plant wilts and dies. When mature plants are affected, lesions appear on the leaves or the veins turn black. As the lesions spread, they become V-shaped yellow-brown dead spots, gradually spreading through the entire head. In the final dry stage they become brittle and crack easily, and under high humidity they rot.
Control method: The disease is prone to occur in high-temperature and high-humidity summer climates. In addition, continuous cropping and improper fertilization can also cause the disease. Likewise, disinfect the soil and seeds before planting, fertilize scientifically and reasonably, and balance various nutrients. When the disease occurs, spray with difenoconazole or thiodiazole-copper for control.
3. Cabbage soft rot
Cabbage soft rot can occur at the seedling stage, rosette stage, and head-forming stage of cabbage, and can affect different parts, such as the root crown, leaves, and head. In the end, all lead to rot and death of the affected parts.
Control method: The disease is prone to occur in the rainy season, with excessive watering, and when leaves have cracks or wounds. When planting, avoid continuous cropping with solanaceous and cucurbit vegetables, and avoid planting in low-lying plots with heavy clay soil. Disinfect the soil and seeds before planting. After the disease occurs, promptly pull out diseased plants with their roots and carry them out of the field, then spray with benzothiazolinone or kasugamycin for control.
4. Insect pests
The main insect pests of cabbage are diamondback moths and aphids. They either chew the leaf mesophyll or suck the leaf sap, ultimately causing the leaves to dry and curl, and in severe cases causing the death of the cabbage.
Control method: Frequently remove weeds to reduce the living environment of insects. Greenhouse technology can also be used to seal the area for 3-5 days so that high temperatures kill the insect sources. In addition, chemical control can be used.