Broccoli likes cold and warm, the plant growth temperature is 20~25℃, the bud development temperature is 20~22℃ for early-maturing varieties, 18~20℃ for middle-maturing varieties and 15~ 18℃ for late-maturing varieties. The flower ball will freeze at the low temperature of -3~-5℃. Flower bud differentiation is not strict with low temperature, and the condition of flower bud differentiation of early-maturing varieties is below 22℃, 2 1 day, so floret balls will be formed at low temperature at seedling stage. It takes 28 days for mid-maturing varieties below 17℃ and 35 days for late-maturing varieties below 12℃. Early sowing of late-maturing varieties can not achieve the goal of early harvest. Broccoli requires sufficient light, not strict on the length of sunshine, strict on water, and neither waterlogging nor drought tolerance. The demand for fertilizer is similar to that of cauliflower, and a certain amount of trace elements such as calcium, boron and molybdenum are also needed. Wide adaptability to soil, especially suitable for planting in shallow ponds and mud fields along the coast.
(2) Main varieties
Broccoli varieties are mostly hybrids. According to the days from planting to harvest, they are usually divided into four categories: extra early maturity (within 60 days), early maturity (60-70 days), medium maturity (70-90 days) and late maturity (more than 90 days). Variety selection should be based on the cultivation season. At present, the main cultivated varieties of broccoli in our county are as follows.
1, a very early-maturing variety
Green wind: produced by Japanese company Musashino. It is specially used for topping flowers. Its plant height and spreading degree are 55 ~ 60 cm. Its leaves are needle-shaped, grayish green and slightly wrinkled. The flower head is bright green, the bud is delicate, easy to be hollow, resistant to disease and heat, poor in cold resistance, and easy to turn purple when it is cold, so its suitable planting period is narrow.
2. Early maturing varieties
(1) Excellent: produced by Sakata Company, Japan, with main flower heads, plant height and spreading degree of 65~70cm, wide lanceolate leaves, grayish green, slightly wrinkled, bright green flower heads, thin buds, difficult to hollow, heat-resistant, drought-resistant, cold-resistant and disease-resistant. The flower head will turn purple when it is cold, which is suitable for a wide planting period.
(2) Mantuo Green: produced by Syngenta of the Netherlands. It is specially used to top the flower ball. Plant height and spreading degree are 70 ~ 75cm. The leaves are oval, gray-green, slightly wrinkled, the flower heads are bright green, the buds are delicate, easy to hollow, with strong disease resistance, poor heat resistance, drought resistance and cold resistance. The flower ball is easy to turn purple in cold and drought, and the suitable planting period is narrow, which is not suitable for FD dehydration processing.
3. Medium-mature varieties
(1) Luxiong 90: produced by TOKITA Company, Japan, with special flower heads, plant height and spreading degree of 75-80 cm, wide lanceolate leaves, dark green and slightly wrinkled leaves, bright green flower heads, delicate buds, difficult hollowing, strong cold resistance and disease resistance, poor heat resistance and drought resistance, and no resistance to black rot. Flower heads encounter low soil moisture.
(2) Lvxiong 95: produced by TOKITA Company of Japan, with the same characteristics as Lvxiong 90 except that the growth period is slightly longer than that of Lvxiong 90.
4. Late-maturing varieties
(1) Holy Green: produced by Nozaki Company of Japan. The main side flower head has both uses. Plant height and spreading degree are 75 ~ 80 cm. The leaves are broad and lanceolate, bright green and shriveled. The flower head is bright green, the bud is delicate and easy to be hollow. Flower heads are cold-resistant and will not turn purple. Their heat resistance, drought resistance and disease resistance are very poor. The incidence of brown stem disease is 50% all the year round.
(2) Li Chao: produced by Takui Company in Japan, with main lateral head, plant height and spreading degree of 75-80 cm, long and narrow leaves, bright green, shriveled flower heads, tender buds, hard hollowing, strong cold resistance, purple flower heads when cold, poor heat resistance, drought resistance and disease resistance, and the incidence of perennial brown stem disease is 30%.
(3) Fuxing: produced by Japan Sakata Company, with the same characteristics as Li Chao.
(3) Cultivation techniques
According to different cultivation seasons, it is divided into autumn and winter broccoli (sowing in summer and autumn, harvesting in winter and spring) and spring broccoli (sowing in winter and harvesting in spring and summer).
1, autumn and winter broccoli
The suitable sowing date of broccoli in autumn and winter is generally in late July, early August, middle August and late September. Other cultivation techniques are the same as cauliflower.
2. Broccoli in spring
(1) Variety: ① Excellent: 65438+ 10 sowing in the middle and late October, harvesting from the end of April to the beginning of May; ② Mantuo Green: 65438+sowing in mid-February and harvesting in late April.
(2) Seedling raising: ① Seedling raising method: seedling raising with plug insulation, with leaf age of 4.0-5.0 leaves and seedling age of 45-50 days. (2) Seedbed layout: Choose fields with flat border, convenient water intake and no flooding, and use plug seedlings. 80% of fertile mountain soil or pastoral soil which has not been planted with cruciferous vegetables for two years and 20% of loose organic fertilizer which has been decomposed and screened are used as the substrate, and the soil is fully irrigated with fertilizer water with a fertilizer content of 0.5% and a proper amount of pesticides such as hymexazol and Bestar before sowing. (3) Precision sowing: firstly, the germinated seeds are sown in the holes, covered with a double-layer sunshade net, and then covered with a film, and then a small bow shed is built to cover the film for heat preservation and seedling raising, or a greenhouse is used for heat preservation and seedling raising, and water is sprayed to keep moisture according to the moisture in the holes. ④ Seedbed management: a, root protection: after the seedlings are planted to 50%, remove the surface root protection, cover them with a small arched sunshade net for 3-5 days in sunny days, then remove the sunshade net to keep warm and raise seedlings, and protect the roots with burnt mud, knife-edge sand or shriveled particles once. When the temperature in the shed is higher than 30℃, it should be ventilated to cool down. When the temperature is lower than 0℃ in the cold wave at night, thermal insulation materials such as straw curtains and non-woven fabrics should be covered outside the film before 4 pm to prevent freezing. B fertilizer water: water is poured once every sunny and hot morning 1~2 days. Generally, only clean water is sprayed before the first two leaves, and 0.5% compound fertilizer water is added when watering after the first two leaves, and it is watered twice every 5~7 days. C before pulling out seedlings: hardening seedlings, watering and taking medicine to the field before pulling out seedlings, which is equivalent to broccoli in autumn and winter.
(3) Planting: ① Soil preparation and fertilization: before planting 15 days, apply decomposed organic fertilizer 1000 kg or commercial organic fertilizer 100 kg, urea 10 kg, and 50 kg of calcium superphosphate, and apply urea10 ~ before planting. For fields without organic fertilizer, 35 kg of compound fertilizer and 35 kg of calcium superphosphate are applied to each mu of the whole field before ploughing, and 20 kg of urea and 2 kg of borax are applied before soil preparation after ploughing. Soil preparation requires deep and high border, with a border width of 2m and a border width of 0.3m, and a deep waist border. ② Chemical weeding: 0~2 days before planting 65438+, 72% Dur EC+10% glyphosate aqueous solution was evenly sprayed 750 times per mu on the border. ③ Planting: density: 2,200-2,400 plants per mu, that is, 4 plants per border with a spacing of 0.50-0.55 m .. b Planting: it can be planted all day, and the seedlings should be separated. After planting, 0.5% compound fertilizer should be poured to fix the root system and fertilize the water. When planting in a field with loose and dry border, seedlings should be sown first, and then covered with plastic film after the soil moisture improves. For fields with tight ridges and good soil moisture when planting, plastic film should be covered before seedling raising. Selection of C membrane: the membrane should be made of high-quality products with strong puncture resistance, and the specification is 0.0 14mm thick and 2m wide. D film mulching: when film mulching, the soil around the film should be solid, and the plants should be sealed with soil, but the middle part should be covered with mud as little as possible.
(4) Fertilizer and water management: topdressing is generally only applied once, that is, compound fertilizer 10kg and urea 10kg are applied per mu at the initial stage of germination, and the application method is to break the membrane between every two broccoli plants. During the growth period of broccoli in spring, there is usually more rain. Except for planting roots and fertilizing and watering, there is generally no need to water, but attention should be paid to ditch cleaning and drainage.
(4) Pest control
Brown stem disease is the main obstacle to broccoli production in autumn and winter. The incidence varies greatly among different varieties. You, Mantuo Green, Luxiong 90, Luxiong 95 and other early and middle maturity varieties are basically free from diseases. The incidence of late-maturing varieties such as Lu Sheng, Fuxing and Li Chao is 20-50%, and the weight is 80%, which is caused by downy mildew. After the late-maturing varieties germinated, they were treated with 58% Domil Mn-Zn wettable powder 800 ~ 1000 times twice, and the disease control effect could reach 90%. The occurrence types, control principles and application methods of other pests and diseases are the same as those of cauliflower.
(v) Control of undesirable phenomena.
1, hollow, split stem
① Reasons: The main reasons are boron deficiency, biased application of nitrogen fertilizer or long-term drought and lack of rain. ② Preventive measures: Use 2kg/ mu borax as base fertilizer or spray 600 times 10% liquid boron fertilizer 2~3 times at the initial stage of germination to strengthen fertilizer and water management.
2, Lei Huang, banana head
① Cause: It is mainly caused by abnormal climate such as high temperature, drought, low temperature freezing injury or intermittent sunny and rainy weather. ② Preventive measures: mainly select varieties with strong resistance and take appropriate field management measures.
(6) Harvest
1, harvest in time
When the flower ball size reaches the collection standard, it should be harvested in stages and batches. Generally, harvesting is completed before 9 am on sunny and hot days, and can be harvested all day on rainy days.
2. Harvest method
Harvest with a kitchen knife or a special knife for broccoli harvesting. When harvesting, the stem length shall not be shorter than 18cm, and the leaves shall be cut off. After the big leaves are torn off, the flower balls should be transported to the processing enterprises in time in plastic baskets to prevent damage, pollution or water loss and deterioration.