Detailed Explanation of Key Points for Pollution-Free Cultivation Techniques of White Radish
White radish is a common vegetable. As the saying goes, “Eat radish in winter and ginger in summer.” It is also a nourishing food ingredient in winter, containing mustard oil, amylase and crude fiber, and has the effects of promoting digestion, enhancing appetite, accelerating gastrointestinal peristalsis, and relieving cough and resolving phlegm. So, what are the key points for pollution-free cultivation techniques of white radish?
1. Land preparation and fertilization
Select a pollution-free plot. On the basis of applying sufficient base fertilizer, break up stubble and prepare the land, plowing 30cm deep in autumn. For plots with crop rotation and replanting, land preparation should be carried out immediately after the previous crop is harvested. Remove residual stubble and weeds, apply 45t/ha of high-quality farmyard manure, mix in 300-450kg/ha of diammonium phosphate or compound fertilizer as basal fertilizer, and form ridges 55-60cm wide and 25cm high.
To control underground pests, mix 50% phoxim emulsifiable concentrate at 52.5L/ha into toxic soil and apply it in strips along the furrows with the base fertilizer (the use of highly toxic and high-residue pesticides is prohibited). The organic fertilizer applied must be fully decomposed, otherwise it easily damages the main root, forming forked roots and affecting yield. Maggots are the main pests harming radish growth. They tend to be attracted to putrid organic matter, so attention should be paid to this in production.
2. Sowing
The sowing time is from June 25 to July 5. Use high-ridge spot sowing or dig holes and sow with water. The sowing rate is 00-75kg/ha; plant spacing is 23cm, with 70,000-75,000 plants/ha retained. Place 4-5 seeds per hole, scatter the seeds within the hole, and cover with 2cm of soil so that the seeds are in close contact with the soil, preventing “bud drying” caused by drought and “seedling suffocation” caused by water accumulation, thus ensuring full and strong seedlings.
3. Field management
(1) Thinning
Thinning should not be done too early, because the fleshy root is formed by the elongation of the hypocotyl. Properly delaying thinning is beneficial to hypocotyl elongation. Thinning can be completed in 2 rounds. The first thinning is at the 3-true-leaf stage, leaving 2 plants per hole. The second thinning is final thinning at the 5-true-leaf stage, leaving 1 strong seedling per hole.
(2) Cultivation
Cultivation loosens the soil, promotes root growth and development, and enables the main root to penetrate deeply. It is required to hoe deeply in the furrows and shallowly on the ridge backs. Hoe deeply when wet and shallowly when dry; shallow at the beginning and deeper in the middle, without damaging the main root.
(3) Water and fertilizer management
After entering the root-breaking stage, control water to promote seedling hardening. During the fleshy root expansion stage, irrigate to maintain field water-holding capacity at about 60%. If the base fertilizer is insufficient, topdress with urea and potassium sulfate at 150-225kg/ha in combination with irrigation, applying by punching holes 10cm away from the seedlings. Foliar fertilizers such as 0.5% potassium dihydrogen phosphate can also be sprayed, with an obvious yield-increasing effect.
4. Pest and disease control
(1) Agricultural control: select disease-resistant varieties according to local conditions or use comprehensive cultivation measures to prevent disease and reduce pesticide use; implement crop rotation, remove diseased plant residues from the field, and deep-plow and prepare the land to reduce the pest and disease base; apply clean fertilizer, ensure organic fertilizer is fully decomposed, and irrigate with clean water.
(2) Physical control
Install insect-proof nets, use black light lamps to trap and kill adults, use silver-gray film to repel aphids, and properly disinfect seeds to prevent viral diseases.
(3) Biological control
Protect natural enemies, create environmental conditions conducive to their survival, and choose biological agents harmless to natural enemies or pesticides with low lethality, such as imidacloprid, avermectin, Bacillus thuringiensis and other pesticides.
(4) Chemical control
Promote the use of high-efficiency, low-toxicity, low-residue pesticides, and prohibit the use of highly toxic, high-residue pesticides. When using pesticides, strictly follow the safety standards promulgated by the state to ensure the production of pollution-free agricultural products.
5. Harvesting and processing
Harvesting generally begins in early September. Before processing, cut the radish top down to the leaf base, wash clean with clear water, and change the water frequently so as to process clean white radish strips. The processing knives are generally self-designed. The “five-knife” method processes them into 1cm square strips; the “one-knife” method processes them into triangular strips, forming 4 large pieces, with thicker radishes processed into 6-8 pieces. The triangular strips should not be too thin, and processing must be carried out strictly according to requirements. Hang the processed radish strips in a ventilated place to dry. It is best to spread them in 1 row in the field, divided into upper, middle and lower 3 layers. When drying in the courtyard, build a high rack, with the distance between the radish strips and the ground not less than 1.2m. When dried to 90% dry, they can be taken down from the rack, sorted by length, tied into 0.5kg/bundle, tied firmly, and required to have a neat bundle shape. Place in a ventilated place to dry in the shade until sold.
Pollution-free white radish cultivation should give priority to the use of comprehensive agricultural control techniques, combine biological control and physical control, and scientifically and rationally apply chemical control methods, so as to minimize the use and residues of pesticides and produce white radish that meets national standards.