How to manage Chinese cabbage during the rosette stage? These measures need to be mastered
Symptoms: It occurs in all regions and can cause damage both in the field and during storage. The disease usually starts at the base of the leaf stalk and spreads to the entire leaf and then the whole cabbage plant. The diseased part rots, and white cottony mycelium and black sclerotia grow on the surface. On seed-producing plants, the stems are mostly affected; the stalk area is initially light brown and sunken, then turns white, and the cortex decays...
I. Fertilizer and water managementDuring the rosette stage of Chinese cabbage, both growth speed and growth volume are very fast, and the fertilizer requirement increases. In the early rosette stage, a "plant development" fertilizer should be applied as a top dressing, with 8-10 kg of urea per mu. The method is to open a 10 cm furrow on one side of the ridge, apply the fertilizer, close the furrow, and water. When opening the furrow, be careful to damage the roots as little as possible.
II. Seedling hardening to promote root growth
From the middle rosette stage to the heading stage, Chinese cabbage should have watering controlled for seedling hardening, to curb excessive growth, make the leaves thicker, promote root development, help nutrient accumulation, reduce field humidity, and control the occurrence and development of diseases. The seedling hardening period varies from 10-20 days, and the leaf color changes from green to yellow or shows slight wilting at noon. In the following situations, reduce seedling hardening: varieties with a short growing period and fast growth, those sown too late, those transplanted as large seedlings, those with poor seedling condition, dry areas with little rain and higher temperatures, and sandy land lacking water and fertilizer.
III. Pest and disease control
The main diseases of Chinese cabbage during the rosette stage are downy mildew and soft rot. Control methods: First, control humidity to prevent downy mildew and soft rot. Second, when disease is found, apply pesticides at the right time to control the development of the disease.