1, temperature:
The optimum temperature for the growth and development of broccoli is 20-22℃, which is slow above 25℃ and slow below 5℃, and can withstand short-term frost. Different varieties and different growth periods have different requirements on temperature: the suitable temperature for seed germination is 15-30℃, and the suitable temperature for growth and development is 8-24℃. The flower bud differentiation period requires strict temperature, and the transformation from leaf cluster growth to flower bud differentiation and bulb formation requires necessary low temperature stimulation. Generally, the temperature is 22-23℃ for extremely early-maturing varieties, 65,438+07-65,438+08℃ for early-maturing varieties, 65,438+05-20 days for early-maturing varieties, 22-25 days for middle-maturing varieties and 30 days for late-maturing varieties, which are lower than 5℃.
2. Lighting:
Broccoli is a low temperature and long sunshine crop, which likes light. Under the condition of sufficient light, the growth and development are normal, the flower head is compact, the color is normal and the commodity value is high. When the light is insufficient, the plants grow poorly, are short, the flower stems are elongated, the flower heads are small and the color is abnormal, which seriously affects the quality of flower heads. Therefore, the growth process of broccoli and the flower ball must be exposed to the sun, unlike broccoli, which has its own bunches of leaves to avoid yellowing and affecting the quality of the flower ball.
3. Humidity:
Broccoli likes humid environment and needs more water, especially after flower bud differentiation, which inhibits flower ball formation and reduces yield and quality. The relative water content of soil is 70-80%, and excessive humidity will cause plant diseases and flower rot. It is required that the relative humidity of the air should not be too high, and the flower ball formation period is 80-90%. Especially in summer cultivation, rain and dew should not fall directly on the flower ball to avoid the flower ball rotting. The lack of water before the flower ball is harvested will lead to the variation and looseness of the flower ball and affect the yield and quality.
4. Soil:
Broccoli has low requirements on soil, and all kinds of soil are suitable for its growth and development, but loam or sandy loam with rich organic matter, deep soil layer, loose air permeability and good drainage is the best. The suitable pH range is pH 5.5-8.0, and it grows well around pH 6.0.