When is the most suitable time to plant mustard tuber in northern China?
AbstractIn northern China, the suitable planting time for mustard tuber is around August 16. If mustard tuber is planted too early and encounters hot weather, the fleshy stem of the mustard tuber is prone to longitudinal splitting, hollowing, and bolting, and it is also likely to cause the occurrence of some diseases. If mustard tuber is planted too late, it will shorten the growth period of the mustard tuber, resulting in a small fleshy stem and reduced yield.
1. Planting time
In northern China, the planting period for mustard tuber is around August 16. The suitable temperature during the fleshy stem growth stage of mustard tuber is 13-18°C. If mustard tuber is planted too early, when the weather is hot, the fleshy stem of the mustard tuber is prone to bolting, longitudinal splitting, and hollowing, and may cause the occurrence of viral disease. If mustard tuber is planted too late, it will shorten the growth period of the mustard tuber, leading to a small fleshy stem and low yield. Therefore, it needs to be planted at the appropriate time.
2. Selecting varieties
1. In Sichuan, the growth period of planted mustard tuber is 160-170 days, while in northern China, due to the influence of climatic conditions, only early-maturing varieties with strong adaptability and resistance to bolting can be planted. After many years of experiments, it has been proven that “Qingyuan Early Mustard Tuber”, bred by the Qingdao Academy of Agricultural Sciences, is relatively suitable for planting in northern China.
2. This variety has good quality and no fiber, responds relatively slowly to day length, and is not prone to early bolting. Its growth period is about 70 days, the weight of a single fleshy stem is 250 grams, the yield per mu is 2000-3000 jin, and 1000 jin of tender leaves can also be harvested.
3. Fine land preparation
It can be planted in fertile land with loose soil. After the previous crop is harvested, apply 10000 jin of decomposed high-quality barnyard manure plus 80 jin of nitrogen-phosphorus-potassium compound fertilizer per mu as base fertilizer. After deep plowing, harrowing finely, and leveling the soil, make wide and low ridges with a ridge surface width of 36-40cm, a ridge height of 10-15cm, and a ridge bottom width of 26-30cm, with a ridge spacing of 60-70cm. Once the ridges are properly prepared, sowing can begin.
4. Reasonable close planting
1. Mustard tuber seeds are relatively small, so their ability to sprout and push through the soil is weak, and fine sowing is required. Two shallow furrows 2cm deep can be opened on the ridge, then the seeds are evenly broadcast in the furrows. The seeding rate per mu is about 150 grams. After sowing, cover with fine soil, but do not cover with too much soil, otherwise it will be unfavorable for sprouting and emergence.
2. After raking the ridge surface flat, spray water, then spray water once each on the 2nd-3rd day. After sowing, wait 3 days for emergence. After the seedlings emerge from the soil, thin and finalize the seedlings in time.
3. The first thinning can be done when the seedlings are at the “cross” stage, and the second thinning can be done when the seedlings have grown 3 true leaves. During this period, diseased, weak, and mixed seedlings can be pulled out. Along with thinning, carry out intertillage and loosening of the soil, which is beneficial for enhancing soil permeability, then remove field weeds. Final seedling setting can be done when the seedlings have grown 4-5 true leaves. The plant spacing should be maintained at about 20cm, with 8500-9000 seedlings established per mu.
5. Field management
1. The first topdressing can be carried out after the second thinning at the seedling stage, applying about 10 jin of ammonium sulfate per mu, which can be spread on the side of the ridge to help promote healthy growth of the seedlings. When the 5th true leaf has grown, the second topdressing can be carried out after final seedling setting and intertillage, which is beneficial for promoting the plants to develop as quickly as possible. Apply 30-40 jin of ammonium sulfate, 30 jin of potassium sulfate, and 300 jin of plant ash per mu, scattered in the ridge furrows.
2. After each topdressing, water in time. In late September, when the plants are close to closing the rows, carry out the third topdressing, which is beneficial for promoting rapid growth of the plant stems. Apply 40-50 jin of ammonium sulfate per mu, which can be applied by flushing with water. After the third topdressing, the plants begin to enter the vigorous growth period. Water once every 5-6 days, which is beneficial for promoting healthy growth of the plants and the normal development of the fleshy stems.
6. Pest and disease control
1. Viral disease: A mixture of 1.5% Zhibingling emulsion 400-500 times dilution, 20% Virus A wettable powder 500 times dilution, and Zhanyeling 800 times dilution can be used, spraying once every 10 days for 2-3 consecutive sprays.
2. Soft rot: In the early stage of the disease, agricultural streptomycin 4000-5000 times dilution can be used, sprayed 2-3 times continuously, so that the liquid flows to the base of the leaf stalks and around the fleshy stems.
3. Downy mildew: In the early stage of the disease, spray 70% mancozeb wettable powder 500 times dilution, 75% chlorothalonil wettable powder 500-600 times dilution, or 64% oxadixyl wettable powder 400-500 times dilution, once every 7-10 days, and continuous control can be carried out 2 times according to the condition of the disease.
4. Aphids and cabbage caterpillars: Spray with 20% fenpropathrin-malathion emulsion 1000-1500 times dilution or 2.5% deltamethrin emulsion 2000-3000 times dilution.
5. Striped flea beetle: Spray with 50% phoxim emulsion, 80% dichlorvos emulsion 1000 times dilution, or Uranus emulsion 5000 times dilution, once every 7-10 days for 2-3 consecutive sprays.