One is to select the varieties and sow them in time. Autumn cabbage in the lower-middle part of the yangtze river should be selected for pre-cooked varieties with high heat tolerance and large flowers. The main varieties are guangdong early flowers, sui-hai early flowers, morning flowers 6, chongqing small flowers, white sands, coyo-fou, white peaks, coyo-fongs 55 days. The appropriate planting period is from late june to mid-july. The second is to make a bed to fertilize and keep the sun warm. The choice of a cool ventilated, deep earthy, lax, well-drained and close to the water source is made as a seedbed. About 15 days before the seeding, the ground was turned to 20-25 centimetres deep, tanned, lime 100 grams per square metre or flint 10 grams for soil decontamination. 5-6 days later, the bed is made of ditches, 1. 5-1. 7 metres wide and 7-10 metres long, depending on the terrain. After making the bed, the soil is fertilized by 300,000 to 4,000 kg per acre, human and animal dung by 2000 to 3,000 kg, calcium perphosphate by 50 to 75 kg, grasswood ash by 120 to 150 kg, so that it can be sowed. In general, 30 m2 of seedbeds are planted in 40 to 50 g (one acre of field can be established). The pre-plant seedbed shall be soaked with water, which shall be then covered with concrete soil (fitting the seed) and covered with a straw (e. G. Straw, straw, straw, etc.) to keep the water wet. When the seedlings come out of the ground, they are removed from the stubbles on the side, then placed in a sunshield, which is 0. 8 to 1 metres high and covers with a membrane, with straw curtains or sunnets. Every day, between 8 and 9 a. M. And 4 and 5 p. M., covered with straw curtains or sunnets, and removed at night and in the dark. As the growth of seedlings increases light time, five to seven days before planting, the sunshields are removed and the seedlings gradually adapt to the climate outside the shed. Heavy rains are used temporarily to cover the arctic membranes and to prevent rain-fed seedlings. When the seedlings have 2 to 3 saplings; two to three saplings at 7 to 8 centimetres, they are eliminated. After the sapling, water is poured and fat is followed by water. 1% urea per 10 m2 seedbed 500 kg. Water every 2-3 days from now. When the climate is hot, water is watered with diligence; when it rains, it is watered for longer periods, and care is taken to prevent bed impregnation。
