Onion is a vegetable that is not used for continuous cropping. The seedlings must be selected from the high pits of non-onion and garlic crops and should not be chosen for wasteland. After harvesting the former crop, it was sun-dried twice and left unused for about 20 days. The green onion seedling period is as long as 50 days. Before the site preparation, organic biological fertilizer 6000kg/hm, superphosphate 750kg/hm, and imported compound fertilizer 225~300kg/hm are applied. Build a flat width 1.5m wide, fine land preparation. In order to prevent and control the damage of underground pests, 3% phoxim granules of 150kg/hm were applied during site preparation and a ditch system was established around the fields. The major varieties of export onion are Changbao, Changyue, and Akihiko. For every 100g of seeds, 35~40m of seedbed is required, and 666.67m of field can be transplanted. Early-maturing varieties were sowed on March 10-25, and late-maturing varieties were sowed from the end of March to April 10. Before the planting, the soil moisture is insufficient and you can water it first. Generally spread evenly, spread the seeds, and then gently water on the surface. After watering, cover the fine dry soil 0.5cm thick. Do not water after covering the soil to prevent soil compaction, then cover the plastic film and take a small arch. It is beneficial to warming, moisturizing, and preventing rain from contributing to soil compaction, but it is necessary to prevent high temperatures from burning seedlings. Onion seeds germinate fastest around 18°C, and can emerge after 5~6d sowing. 60% of the mulch film was removed in time after emergence, and the film was too late to cause seedling growth. Before the rain, cover the film on the small ring and remove the film after the rain. During the seedling stage, according to the soil moisture, one or two small waters can be poured, and the water should not be too much, so that the seedlings will not grow. The whole seedling topdressing 3 to 4 times, quick-acting organic fertilizer and imported compound fertilizer used alternately, the chemical fertilizer concentration does not exceed 0.5%, prompting the seedlings to grow robustly. During the nursery period, if the seedlings are rooted, the dry fine soil shall be covered in time, and the weeding bed shall be timely weeding and pest control.

2 Site preparation

Welsh onion is suitable for the growth of well-drained, deep and fertile loam soils. Sandy soil is easy to insert onions, loose soil and earth, good ventilation, easy access to high yield. Immediately after the harvest, the land was deep-turned 25 to 30cm, plowed and sun-dried, combined with high quality decomposing organic fertilizer 30t/hm for soil preparation and rice field with low soil fertility. The amount of organic fertilizer increased accordingly. After open-rotating and mixing, the ditch was opened and the depth of the ditch was 30cm and the width was 20cm. The distance between the two ditch was 1m. Tillage in the ditch, depth 20cm, basal fertilization at the bottom of the trench, mainly organic fertilizer, so that the soil and fertilizer mix, the soil in the trench is required to be loose. The back of the ditch should be more than 30cm above the ditch, and the ditch should be north-south, so that the light can be evenly distributed, and the north strong wind in the autumn and winter seasons can reduce the onion lodging. Daejeon is surrounded by a series of trenches, and a gap of 20~30m is used to open a gutter for drainage. Planting time is generally from late May to mid-June. The size of the seedlings before planting was classified, and diseased seedlings, weak seedlings, over-seedlings, and apparently curved seedlings were removed. The plant spacing was 2.5-2.8 cm, the row spacing was 1 m, and the planting amount was 345,000 plants/hm. When planting to avoid the onion seedlings broken, the depth of planting to not bury the green heart is not appropriate, too deep should not be the emergence of seedlings, light to affect the light blue length. Planting tools can use garden iron poles or garden poles with a diameter of about 1.5cm. When planting, first make a shallow hole, perpendicular to the ground, then insert the seedlings, and then lift it up slightly, so that the roots must be laid down to keep the onion sprouts straight. After planting, the sloping soil on both sides of the onion strain was compacted, and then the rooting water was poured.

3 seedling management

Onion seedlings are not tolerant to drought and need to keep the soil moist. Otherwise, the growth is slow and uneven. 30 days after sowing, seedlings, weeding, watering seedlings, 1 to 2 times, seedlings from about 10 cm. 1 leaf 1 heart to 2 leaves 1 heart with water can be applied quickly available nitrogen fertilizer, urea 5-10 kg per acre; at the same time doing a good job of seedling pest control work, with the control of 1-2 times mycotoxin. Before transplanting and planting, nitrogen-controlling seedlings were planted to promote the seedlings to be more robust.

4 scallion nutrition characteristics and nutrient absorption

Welsh onion is a fertilizer crop, with a long growth period, high yield, and a large amount of fertilizer, and the demand for fertilizer increases with the increase in production. According to the research, high-yielding cultivation of green onion yield can reach 80~90t/hm, each production of 1t green onions needs pure N2.7~3.3kg, P2O50.5~0.6kg, K2O3.3~4.0kg, the absorption ratio of NPK is 1 : 0.4:1.3, with the most potassium, nitrogen, and phosphorus. The demand for nitrogen and potassium is relatively large, and it is more sensitive to potassium nutrition.

Onion growth stage can generally be divided into five periods: germination period, seedling period, seedling growth period, vigorous vigorous growth period and flowering and solid period. In the seedling stage and the slow seedling stage, onion growth was slow, dry matter accumulation was low, and the nutrients absorbed were also small. Nitrogen, phosphorus, and potassium were the three elements that absorbed more nitrogen and potassium. In the vigorous vigorous light-green period, the scallion dry matter accumulated rapidly and absorbed the most nutrients. The amount of nitrogen and phosphorus absorbed was as high as 68.4% and 46.4% of the absorption during the whole growth period, respectively. On the other hand, the accumulation of dry matter in the late growth period of Welsh onion was slower and the nutrients absorbed were also less, but the absorbed P and K increased significantly, accounting for 44.1% and 34.6% of the total absorption during the whole growth period.

5 Welsh onion fertilization technology

5.1 amount of fertilizer

Based on the application of high-quality organic fertilizer 30t/hm, suitable fertilization amount is 350-450kg/hm for nitrogen (N), 90-120kg/hm for P2O5, and 300-450kg for K2O in moderately fertile plots. /hm, equivalent to about 750~1000kg/hm of urea, ordinary calcium phosphate (12% available phosphorus) 750~1000kg/hm or diammonium phosphate (46% available phosphorus) 200~260kg/hm, potassium chloride (effective Potassium content 60%) 500~750kg/hm. In the case of low soil fertility and lack of organic fertilizer, higher fertilization rates may be considered; conversely, if the soil fertility is high and the soil foundation is good, the fertilization amount may be appropriately reduced. When using diammonium phosphate, the amount of urea can be reduced by 10% to 15%.

5.2 Fertilization method

Before the green onions were planted and transplanted, 40% of the N, K and all P fertilizers were mixed as the base fertilizer and spread in full depth. The remaining 60% of nitrogen and potassium fertilizers were used as topdressing, combined with earth for two times in mid-September and mid-to-late October.

6 Pest control

We must adopt the strategy of "prevention-oriented, comprehensive prevention and control" to control agricultural pests and diseases and strengthen agricultural control. The prevention and treatment of spraying in time in a critical period to effectively control the occurrence of pests and diseases. The use of drugs with high efficiency, low toxicity, low residue pesticides or biological pesticides, strict mastery of pesticide use safety interval. Onion diseases mainly include purple spot, downy mildew, and soft rot. Can be used at the beginning of the disease with 64% anti-virus drugs, onion garlic ginger grams, agricultural streptomycin and other control. Insect pests should be treated early, locusts, thrips, leaf miners in the stage of harm stage, with a net, a good winter, fly Bonte and other prevention and control; Spodoptera litura, etc., in the 1-2 instar larvae, with the leaf to kill, etc. Chemical control.

(1) Onion thrips, leaf miners are sprayed with 40% dimethoate emulsion or 80% dichlorvos emulsion 1000-1500 times.

(2) Onion flies were treated with 90% trichlorfon water 1000 times to root.

(3) Downy mildew can be sprayed with 75% chlorothalonil 600 to 1000 times. 4 purple spot can spray 1:1:200 Bordeaux mixture. Or 65% dexamethasone 600 to 700 times, or 65% thiram zinc 600 to 700 times liquid control.

7 Scallion harvesting

Harvesting period of green onions, due to regional climate differences and sooner or later, in principle, green onions should be shaved (before and after snow), can also be listed in advance (depending on the market may be), or onion after the winter market, this is also the onion products A big advantage (a flexible plan). The green onions harvested before freezing are shaken off the soil, bundled in bundles after proper drying, stored in a cool, dry place, and placed straight down so as to supply the market at any time.

Disclaimer: Some articles in this website have been transferred from the Internet. If you are involved in third party legal rights, please inform this website. phone

Supplier Extract Powder

We're Professional Supplier Extract Powder manufacturers and suppliers in China specialized in providing high-quality products at low price. We warmly welcome you to buy or wholesale bulk Supplier Extract Powder for sale here from our factory. For a free sample, contact us now.

Supplier Extract Powder,Supplier Extract ,Supplier Powder Manufacturer in China

Shaanxi Kang New Pharmaceutical co., Ltd. , https://www.bio-pharmacies.com