The pronunciation of Yuncao is yún tái.

1. Brassica

1. Brassica rapa var.oleifera? DC. is a plant of the Brassica family, Brassica rapa, an annual herb, 30 to 90 cm tall. . Upright, the basal leaves are large-headed and deeply lobed, the top lobes are round or ovate, and the lateral lobes have one to several pairs, ovate; the upper stem leaves are oblong-obovate, oblong or lanceolate; the racemes are in the shape of flowers during the flowering period. The flowers are corymb-shaped, bright yellow, and ovate.

2. The seeds are spherical and purple-brown; the flowering period is from March to April; the fruiting period is from May to June. Rapeseed flowers are mainly produced in Shaanxi, Jiangsu, Anhui, Zhejiang, Jiangxi, Hubei, Hunan and Sichuan provinces in China. They mostly grow in fields, beside rivers and ponds, and in mountain depressions. It likes cold weather and has strong cold resistance. It requires deep, loose and well-ventilated soil. You can choose spring or autumn sowing.

3. Rapeseed flower is one of the main oil plants. The oil content of the seeds is about 40%. The oil is used for food; the young stems and leaves and the total pedicels are used as vegetables; the seeds are used medicinally, and can promote blood circulation, dissolve knots and reduce swelling; the leaves It can be applied externally to carbuncle; the root is used medicinally, and has the effect of cooling blood, dispersing blood, detoxifying and reducing swelling. It is mainly used for bloody dysentery, erysipelas, heat-toxin sores, mastitis, rubella, vomiting blood and other symptoms. It is described in "Newly Revised Materia Medica". It is recorded in "Rihuazi".

2. Morphological characteristics

1. The racemes become corymbose-shaped during the flowering stage and then elongate; the flowers are bright yellow, 7-10 mm in diameter; the sepals are oblong and long. 3-5 mm, erect and spreading, the top is rounded, the edge is transparent, slightly hairy; the petals are obovate, 7-9 mm long, the top is emarginate, and the base is clawed.

2. The siliques are linear, 3-8 cm long and 2-4 mm wide. The fruit petals have midribs and reticulate patterns. The calyx is upright, 9-24 mm long; the fruit stem is 5-15 mm long. . Seeds are spherical, about 1.5 mm in diameter. Purple brown. The flowering period is from March to April and the fruiting period is from May.

3. Value-raising technology

Rational crop rotation and precise soil preparation: Brassica is not tolerant to continuous cropping, and it is not suitable to be rotated with cruciferous vegetables. Otherwise, pests and diseases will easily occur, and the yield per mu will be reduced. will decrease. The rotation effect of brassicas, wheat and beans is better. Brassica seeds are small and the young shoots are not easy to unearth. It is better to choose soil with loose and deep soil, finely crushed and flat, good ventilation, fertile soil, and neutral to acidic pH value.