Environmental requirements for the growth and development of broccoli

Broccoli, also known as broccoli, tender cauliflower and green cauliflower, is not only tender, delicious, nutritious and adaptable, but the requirements of growth and development on the environment are relatively strict.

1. Illumination: broccoli does not have very strict requirements for light, but it likes sufficient light in the process of growth. When the light is sufficient, the plant grows healthily, which can form a strong nutrient, which is conducive to photosynthesis and nutrient accumulation, and makes the flower bulb compact and compact. Bright green color and good quality, too strong sunshine in midsummer is also not conducive to the growth and development of broccoli.

2. Temperature: in the range of 5-25 ℃, the higher the temperature, the faster the growth and development of broccoli. The optimum germination temperature was 20: 25 ℃, and the optimum growth temperature at seedling stage was 15: 20 ℃. Broccoli has strong cold and heat tolerance. The suitable temperature for growth at rosette stage is 20: 22 ℃, and the suitable temperature for flower head development is 15: 18 ℃. When the temperature is higher than 25 ℃, the quality of flower head is easy to deteriorate, but as long as it is not damaged by freezing, the flower head can grow slowly at low temperature even below 5 ℃. The temperature requirements of different varieties and different seedling ages are quite different, so the selection of varieties in the same year is very important.

3. Water: broccoli needs a lot of water in the whole growth process, especially in the period of vigorous leaf growth and flower head formation, even if it is short-term drought, it will reduce the yield. Rainy or high soil moisture at seedling stage can easily cause diseases such as black rot and black spot. During the period of flower head formation, the soil moisture and field capacity is about 70% and 80% in order to meet the growth needs.

4. Soil nutrients: broccoli does not have strict requirements on soil conditions, but if it is too barren, the plant growth is poor, the yield and quality is low, and the over-fertile soil will lead to loose buds and hollow moss. Broccoli is suitable to be planted in the soil with good drainage and irrigation, deep plough layer, loose and fertile soil and strong water and fertility conservation. The range of soil PH was 5. 5-8, but 6 was the best. Broccoli needs sufficient fertilizer during the whole growth process, and its ratio of N, P and K is 14:5:8. The demand for nitrogen was relatively high at the seedling stage, and the demand for P and K was relatively increased after flower bud differentiation. It is noted that in the process of corm development, broccoli needs more trace elements such as boron, molybdenum and magnesium. Boron deficiency often causes the center of the stem to crack, the bulb becomes rust brown and tastes bitter; when magnesium is deficient, the leaves turn yellow; when molybdenum is deficient, the new leaves are whip-shaped and the bulbs are not enlarged. Therefore, the application of appropriate trace element foliar fertilizer before budding will significantly improve the yield and quality.