To achieve high yields in rapeseed, the key is to do a good job of raising seedlings

Rapeseed, also known as oil bok choy or bitter greens, Latin name: Brassica campestris L., a plant of the Brassicaceae family and Brassica genus, native to China. Its stems are dark green, its leaf stalks resemble those of bok choy, and it is a variety of Brassicaceae bok choy; its flowers are yellow. In agronomy, multiple species whose seeds contain oil are collectively called rapeseed. At present, the main cultivated (variety) types of rapeseed are: bok choy type rapeseed, mustard type rapeseed, and cabbage type rapeseed. They are mainly distributed in Anhui, Henan, Sichuan and other places. Rapeseed is rich in nutrients, among which the vitamin C content is very high. Rapeseed generally grows in places with a relatively humid climate, such as southern China. Rapeseed also has many uses; for example, rapeseed flowers can be eaten when the buds are still unopened; when rapeseed flowers are in full bloom, they are also a beautiful scenic sight (Hanzhong City in Shaanxi, China has a rapeseed flower viewing tourist area); after the flowers fade, the rapeseed seeds can be pressed for oil.

The edible benefits of rapeseed

Rapeseed is crisp and tender in texture, with a slight bitterness. It contains a variety of nutrients and is rich in vitamin C. Its seeds have an oil content of 35~50% and can be pressed for oil. Its rapeseed oil is rich in fatty acids and various vitamins, and has high nutritional value. It is not only a good edible vegetable oil, but also has a wide range of industrial uses. The signature nutrient content and dietary therapeutic value of rapeseed can be called outstanding among various vegetables. According to expert measurements, rapeseed contains a variety of nutrients, and its vitamin C content is more than 1 times higher than that of Chinese cabbage. It can promote blood circulation and remove blood stasis, detoxify and reduce swelling, loosen the intestines and relieve constipation, and strengthen the body. It mainly treats migrating wind erysipelas, boils and swellings of the hands and feet, acute mastitis, habitual constipation, calcium deficiency in the elderly, and other conditions.

Strong seedlings are the foundation for “double-low” rapeseed to obtain high yields, and they directly relate to whether a high yield can ultimately be obtained. Therefore, cultivating large, strong seedlings is the core goal and task during the sowing and seedling-raising period of rapeseed. Around this goal and task, the key is to do a good job in the following aspects:

1. Fine sowing, cultivate strong seedlings.

1. Seedbed preparation. For the seedbed land, choose previous crops such as soybean, peanut, and corn on high, well-drained terrain with fertile, loose soil and convenient irrigation and drainage. Vegetable land and continuous cropping land are not suitable for rapeseed seedbeds. The seedbed surface should be level, and the soil particles should be uniform. Generally, about 0.15-0.2 mu of seedbed area is reserved for each mu of main field. Before sowing, finely prepare the land, open ditches and make beds, and combine with land preparation to apply fertilizer evenly so that soil and fertilizer are blended. Generally, for each mu of seedbed, apply 30—40 loads of human and livestock manure, 50Kg of 25% compound fertilizer, and 0.5Kg of agricultural borax.

2. Sow early at the appropriate time. Early sowing within the appropriate period is conducive to cultivating strong seedlings before winter, helps rapeseed recover and grow early, and also creates conditions for timely early transplanting. The suitable sowing period for rapeseed in our county is September 15-25. Sowing too early makes it prone to freezing damage later, while sowing too late is not conducive to cultivating strong seedlings. This year, the rapeseed variety promoted in our county is still mainly the double-low hybrid high-quality rapeseed Qinyou No. 7, with some Qinyou No. 10 planted as a companion variety. Generally, about 0.6-0.75 kg of seed per mu of seedbed is appropriate. When sowing, mix with fine soil and broadcast evenly to avoid clustered seedlings or large gaps. If drought occurs, first water thoroughly or irrigate the furrows to soak enough water, then sow at suitable soil moisture to improve the emergence rate.

3. Strengthen management. During the rapeseed seedling-raising period, drought weather often occurs in our county, affecting emergence. Therefore, if drought weather occurs before the rapeseed seedlings emerge fully, increase the number of waterings to prevent the seedbed soil from drying and cracking; when using furrow irrigation for drought resistance, irrigate and drain quickly, with the bed surface kept moist as appropriate, and do not allow water to accumulate. After the seedlings emerge fully, promptly thin, space, and finalize the seedlings. According to the principles of removing dense plants and keeping sparse ones, removing miscellaneous plants and keeping pure ones, and removing diseased plants and keeping healthy ones, keep a seedling density of 15-18 plants/sq ft. After finalizing the seedlings, promptly apply a light manure water topdressing to settle the roots and promote strength. At the same time, for every fen of seedbed, use 1 bag (15g) of "Aimiaozhuang" mixed with 4-5Kg of water for foliar spraying, which can effectively dwarf the plants, prevent the formation of tall, leggy seedlings, promote rapeseed root development, increase leaf thickness and chlorophyll content, and thereby improve the overall quality of the seedlings. During chemical control, be careful not to spray repeatedly or miss spraying. For seedlings sown late or thin and weak seedlings, the dosage may be appropriately reduced or not sprayed. A few days before transplanting, carefully select pesticides and do a good job in preventing and controlling diseases and pests such as cabbage webworm, aphids, cabbage caterpillars, downy mildew, and root rot, so as to prevent diseased plants and insects from entering the main field.

Rapeseed seedling-stage management measures:

Promptly do a good job in thinning and finalizing seedlings during the rapeseed seedling stage. In method, pull out weak seedlings, small seedlings, and miscellaneous plants, and it is appropriate to leave 2-3 plants per planting hole when finalizing seedlings. Be sure to avoid lax management and failure to thin and finalize seedlings in time; otherwise, rapeseed seedlings will not be strong, individual development will be poor, and growth vigor will be weak like tall, leggy seedlings, which is not conducive to high yield.

Promptly control underground pests. During the rapeseed seedling stage, promptly prevent pests such as cutworms from damaging young seedlings, which would cause missing plants and broken rows in rapeseed. Method: use 30 milliliters of Baishude per mu mixed with water for spraying. For controlling cutworms, choosing around 6 p.m. for treatment gives better results.

Promptly apply seedling fertilizer as topdressing. After rapeseed seedlings are finalized, when the rapeseed has grown to 4-5 seedlings, promptly apply seedling fertilizer as topdressing, applying 15-20 kg of urea per mu. After fertilizing, irrigate promptly, irrigating quickly and draining quickly. Irrigation should be done so that water does not overflow the bed, and the bed surface should absorb moisture (become damp). When the soil moisture is suitable, promptly carry out intertillage and hoeing to remove soil compaction, enhance soil aeration, and benefit root development.