Key Points for High-Quality, High-Yield Broccoli Cultivation and Mushroom Fertilization Techniques
Broccoli, also called green cauliflower, is a famous high-quality vegetable introduced to China from abroad in the late 1980s, and its main edible part is the head. Because broccoli contains glucosinolates, long-term consumption can reduce the incidence of breast cancer, rectal cancer and stomach cancer, and it also helps regulate and prevent high blood pressure and heart disease, and can effectively control the condition of diabetes. It is a specialty vegetable that sells very well on the international market and is a high-grade vegetable for nutrition and health care with great development prospects. Rugao is the main broccoli production base in our province, mainly used for processing and export to Japan and other countries, with relatively high economic returns. The main cultivation technique points are introduced as follows:
1. Selection of varieties and determination of sowing dates
Broccoli is suitable for growing in a cool climate, and in Rugao it can generally only be cultivated in autumn and winter. Broccoli in Rugao is generally used for processing and export, requiring a firm head, dark green color, small to medium florets, mid-to-late maturity, high yield, and a relatively longer harvest period, so that factories can arrange production conveniently. According to these requirements, in recent years the main choices have been excellent early-maturing, heat-tolerant varieties such as Weilai and Youxiu, with 65 to 75 days from transplanting to harvest; sowing from late July to early August, planting from late August to early September, and harvesting from late October to November.
2. Selection of fields
Choose fields with good drainage and irrigation conditions and whose previous crop was not a cruciferous plant (Chinese cabbage, cabbage, cauliflower, radish) as the seedling-raising site and transplanting site.
3. Seedling raising
Because broccoli seedlings are raised in summer or early autumn, adverse factors such as high temperature, frequent rain and many insect pests must be overcome, so seedlings should be raised in facility greenhouses with good ventilation and drainage, shade, and protection from heavy rain.
After sowing, cover the seedbed promptly with plastic film to preserve moisture, add a shade net on top of the film to lower the temperature, cover the greenhouse with a roof film, and add a shade net on top of the roof film, keeping the temperature inside the greenhouse at about 25°C. Check emergence 2 days after sowing, and when about 70% have emerged, remove the plastic film and shade net from the seedbed in the evening.
Seedbed management: do not water before the seedlings break the heart, to prevent the hypocotyl from becoming too long and forming leggy seedlings. The seedling period should not exceed 25-30 days.
The main seedling-stage diseases are: damping-off and Rhizoctonia rot. The control method is, after the seedlings push through the soil,
alternately use 75% chlorothalonil 500-fold solution or 50% carbendazim 500-fold solution and other agents 2-3 times.
4. Apply sufficient base fertilizer and plant at a reasonable density
Before transplanting, apply 100-200 dan of decomposed organic fertilizer per mu, 50 kg of high-concentration compound fertilizer, and about 0.8 kg of boron fertilizer. (Without boron fertilizer the corm is prone to hollowing; it can also be sprayed on the leaves at the 10-12 leaf stage during vigorous growth.) Then plow and make beds, using double rows on high ridges, with a ridge surface width of 1.0 m and a plant spacing of about 40 cm, planting 2700-3000 plants per mu. After transplanting, immediately water thoroughly to settle the roots.
5. Field management
Broccoli likes fertilizer and water, and timely topdressing and watering in stages are the key to high quality and high yield.
Fertilizer management: the entire growth process requires sufficient nutrients, especially before budding; forming enough vegetative mass is the key to achieving high yield and improving the qualified rate, otherwise the head will be loose. The fertilization principle is "apply light fertilizer to promote seedlings, apply sufficient fertilizer to promote plant growth, and skillfully apply fertilizer to promote head expansion." On the premise of applying sufficient base fertilizer, apply topdressing three times, namely 7-10 days after transplanting apply a seedling-promoting fertilizer once, with 5 kg urea plus 100 kg diluted decomposed human manure per mu. At the 10-12 leaf stage apply a plant-growth fertilizer, with 15 kg urea plus 10 kg high-concentration compound fertilizer per mu. At the budding stage, when the flower buds are about the size of a ping-pong ball, apply an expansion fertilizer, with 5 kg urea per mu.
Water management: broccoli has relatively strict water requirements, being neither tolerant of waterlogging nor drought. Water management should be based on field soil moisture conditions, carrying out irrigation and drainage. During the high-temperature period in summer and autumn, irrigation should be done after evening as flow-through irrigation, with no standing water left in the field the next day. After rain, pay attention to timely drainage as well as intertillage and hilling to increase soil permeability and promote root development.
Pest and disease control: broccoli has relatively strong disease resistance and rarely develops disease in normal years. However, if planted too densely, with continuous rain and poor field drainage, diseases such as black rot, root rot and downy mildew can occur. Disease control should focus on prevention; in addition to strengthening water management, the lower diseased leaves should be stripped off in the later growth stage to improve ventilation and light conditions. 15 days after transplanting, every 10-15 days spray 72.2% propamocarb 600-fold solution, or 75% chlorothalonil 500-fold solution, etc., to control downy mildew. To control root rot, alternately use 72% agricultural streptomycin 3000-fold solution, or 77% copper hydroxide wettable powder 1500-fold solution and other agents 2-3 times. The main insect pests are cabbage caterpillars, diamondback moths, aphids, and tobacco cutworms. To control cabbage caterpillars and diamondback moths, use 2.5% Caixi 1000-fold solution, or 5% fipronil 1500-fold solution, or 0.3% matrine 3000-fold solution, etc. For aphids, use 10% imidacloprid 2000-fold solution, or 50% pirimicarb 2000-3000-fold solution, etc. For tobacco cutworms, use 3% chlorfluazuron 2000-3000-fold solution.
In cultivation, phenomena such as "early flowering," "green head," "hairy head" and "purple head" sometimes appear. "Early flowering" means the plant's vegetative growth is insufficient; for example, excessively long seedling age or nitrogen deficiency can lead to premature head formation. When the green bracts or sepals on the flower branches on the head surface grow out prominently, it appears as a "green head." When the style or filament of the flower organ at the top of the head's flower branches extends non-sequentially, it is a "hairy head." Hairy head mostly occurs when there is a sudden drop or rise in temperature or heavy fog near the head's maturity stage. "Purple head" occurs when, near head maturity, there is a sudden low temperature and glycosides convert into anthocyanins (related to variety); varieties with purple hypocotyls are prone to it.
6. Harvesting: generally the purchasing standards for fresh-market export heads are: single head weight about 250 g each, head diameter 11-14 cm, head height 10-13 cm, stem not hollow, head surface tight and round, without bumps or disease spots, and color and florets relatively uniform. Therefore, when the head reaches the standard, harvest and sell it promptly. Harvest in batches, harvesting one as soon as it matures, generally finishing harvest around 9 a.m.; when cutting, cut flat together with about 15 cm of tender stem below the head, then retain 2-3 small leaves around the head, remove the other leaves, and place them in special boxes for transport and sale. (The specifics should follow the factory's requirements.) When boxing, arrange them neatly and do not press them. After harvest, never stack them for too long, to prevent yellowing and water loss. After harvest, the product should immediately be given "quick cooling and high humidity" treatment. That is, after harvest, tidy the product slightly, then immediately precool it - soak it in flowing cold water at 0°C - and store it in a low-temperature, high-humidity environment at 0°C and 95%-100% relative humidity. With this method, it can generally be kept fresh for 8-10 days.