The cultivation techniques of Shanghai Green include land selection and preparation, sowing and seedling raising, transplanting and field planting, artificial management and pest control.

1. land selection and land preparation: choose a field with loose and fertile soil and convenient irrigation and drainage. A month before planting, the soil should be deeply ploughed 25 cm, so that the sun can explode and dry the soil, which can kill germs and pests, improve soil fertility and looseness, and play a very good role in the growth and development of crop roots.

one week before sowing, put 1, kilograms of decomposed dry animal manure into each mu, and thoroughly beat the dry manure and soil with agricultural machinery as base fertilizer. Then make a flat border, and the standard for border making is 1.2 meters wide, 2 cm deep and 3 cm wide.

2. Seeding and seedling raising: 15-2 grams of seeds are used per mu. Generally, farmers usually plant Shanghai Green by direct seeding, which is divided into sowing and drilling. Sowing first drenches the soil until it is wet, and then evenly sows the seeds on the ground.

For drill sowing, the soil should be furrowed at a distance of 2cm per row, then evenly sown, covered with fine soil of 1.5cm, watered until it is wet, or plant ash can be added as base fertilizer. After a few days, the seedlings can emerge, and the soil should be kept moist during the seedling raising period. When the seedlings grow to three leaves, they can be transplanted and planted.

3. Transplanting and field planting: After the vegetable field is cleared, in order to prevent weeds from growing out of the topsoil in the future, herbicide should be sprayed once before field planting. Then transplant the Shanghai green seedlings, and when transplanting the vegetable seedlings, be sure to take the soil out, and pay attention to take it with care to avoid breaking the mound and damaging the root system of the seedlings.

Generally, it is best to plant at five o'clock in the afternoon, and the daily average temperature of planting is 15℃~2℃. Digging hole type planting, one plant in each hole, 2 cm plant spacing, 3 cm plant rows, and planting 1, Shanghai young plants per mu. During the planting period, the seedlings need to be watered frequently to keep the geology moist. After a few days, they basically grow stably and enter the management period.

4. artificial management: topdressing should be carried out once a week after the green planting in Shanghai, during which the soil should be kept moist. topdressing can be mixed with urea 15 kg, compound fertilizer and phosphate fertilizer ***5 kg, and water and fertilizer are applied alternately.

Fertilize once every ten days. Generally, topdressing for three times can enter the harvest period. In case of rainy weather during the management period, drainage should be done well to prevent water accumulation. Weeds should be removed manually in the middle period. If there is animal manure, it can be watered, which will save more cost and investment.

5. Pest control: Pests and diseases in Shanghai are mainly downy mildew, white spot disease, virus disease and leaf blight, as well as aphids, noctuids, diamondback moths and cabbage caterpillars. Diseases can be controlled by chemical spraying, bordeaux mixture or carbendazim.

The pests include aphids, noctuid and cabbage caterpillar, which can be sprayed with trichlorfon, trichlorfon or dimethoate EC. As for the variety of pesticides, they should be used according to the instructions, dosage and proportion before using them.