High-yielding cultivation techniques of local red onion in Shuili

Chives have a long history of cultivation in Guangzhou, especially like to grow red chives (red onions). Local red onion in Shuili is a local variety of Shuili Village, Baiyun District, Guangzhou City, with plant height 55~70cm and development degree 30cm. Leaf length 35~50cm, transverse diameter 0.9~1.2cm, turquoise, less wax powder. Green onion white (pseudostem) long 15~20cm, transverse diameter 1.5~2.0cm. The base forms the small bulb, the spindle shape, the scale clothing purplish red to brown red, flesh white. The plant has strong growth and strong tillering ability, and the yield is 5000kg per 667m ~ 2 after planting to the first harvest for 50 ~ 70 days. Resistant to wind and rain, strong cold resistance, strong aroma. Based on the experience of farmers in cultivating red onions, and through experimental research and production practice, a set of high-yield cultivation techniques of local red onions in Shuili was summarized.

1 preparation before sowing

① chooses sandy loam soil with sufficient light, convenient drainage and irrigation, deep and fertile tillage layer, rich and loose organic matter and strong water conservation capacity. The previous crop should be a non-onion and garlic vegetable crop, and the best crop rotation is flood and drought.

② soil preparation first turned deep into the sun, and then the border surface was broken up, raked flat, and built into a deep ditch and large border. Generally, the width of the border is 2m, the width of the ditch is 50cm, and the depth of the ditch is 50~60cm. Apply sufficient basic fertilizer before soil preparation, and apply 2000~2500kg, peanut bran 50kg and superphosphate 75kg mixed compost every 667m2 of rotten farm manure (such as pig manure, etc.). When preparing the soil, we should make sure that the soil is fine, the ditch is straight, the soil moisture is flat, and the fertilizer is even. At the same time, apply herbicide to replenish 100~150ml/667 square meters.

③ selected red onions with bulbs as seeds, and red onions with large, solid, good shape and no damage should be selected as seeds.

(2) sowing and seedling management

The suitable sowing time of ① sowing in Guangzhou is from mid-late July to the end of September, and the best sowing date is mid-late August. The seed amount is 50~90kg per 667m2, general plant spacing 22cm, row spacing 25cm, and each hole has 1x 2 bulbs. In order to increase the early yield, one row of spring onions was added between rows, and the whole plant was harvested at one time at the first harvest. Soak the seeds of 5~10min with 50% carbendazim wettable powder before sowing, remove them to dry and wait for sowing.

It is suitable for ② to manage shallow species at seedling stage, and it is suitable to use 2, 3, 3 and 4 of onion in the soil. After sowing, the border should be fully watered once, and the border surface should be wet through. The seedlings can be ready in 7-15 days. When the seedling height was about 10cm, water and fertilizer was applied thinly once, and 500kg mature human and animal manure water plus 3~5kg urea was applied every 667m2 to promote root growth and seedling growth, and fertilizer was applied every 10 days. The seedling stage is in early autumn and the weather is dry. It is advisable to be drenched once every two days. If it is hot and dry at this time, pay attention to prevent squatting at the seedling stage.

3. Field management

When the spring onion seedlings grow to about 20cm, it is combined with weeding and topdressing to promote growth and tillering. Generally, ternary compound fertilizer 20~40kg and urea 5~10kg are applied every 667m2, and water is poured through at the same time. Watering should be determined according to the weather conditions, and the border surface should be slightly whitened and watered sooner or later. Too much water, onion leaves grow too fast, green onion growth is affected, and easy to catch disease, lodging, onion red fade. After that, fertilizer is usually applied every 10 days. When the temperature begins to rise in spring, it is necessary to increase the application of P and K fertilizer, especially K fertilizer.

(4) Disease and pest control

The main diseases in Guangzhou are purple spot, rust, downy mildew, leaf blight, gray mold and blight, and the main pests are thrips, Liriomyza huidobrensis, onion flies, beet armyworm and Spodoptera litura. Agricultural measures such as crop rotation, removal of diseased leaves, good field sanitation and control of water and fertilizer are mainly adopted for the prevention and control of diseases and insect pests, and chemical control is supplemented by the use of frequency vibrating insecticidal lamps.

① purple spot disease 40% ethyl phosphine aluminum wettable powder, 58% metalaxyl manganese zinc wettable powder, 64% poison alum wettable powder.

② rust 15% triadimefon 1000 times, 72% agricultural streptomycin 4000 times, 58% onion and garlic disease wettable powder 1500 times, 30% Nuoxi wettable powder 600 times 800 times.

③ downy mildew can be treated with Bordeaux solution 1 ∶ 1 ∶ (200 × 300), 65% Dysen zinc wettable powder 500 × 700 times, 75% chlorothalonil 600 times, 40% ethyl phosphine aluminum wettable powder 200 times, once every 7 to 10 days.

④ leaf blight can be sprayed with 70% Langton wettable powder 800 × 1000 times, Shimei 500 × 800 times, 58% onion and garlic disease wettable powder 1500 times, 30% Nuoxi wettable powder 600 times 800 times.

⑤ gray mold can be controlled with 58% onion and garlic disease wettable powder 1500 times, 30% Nuoxi wettable powder 600 times, Kangkuling 800 times, 64% poison alum wettable powder 600 times.

⑥ blight can be controlled with Kangkuling 800x solution, 64% alum wettable powder 600x solution and 30% Nuoxi wettable powder 600x800 fold solution.

⑦ tip blight is a physiological disease, which is mainly caused by chlorosis of leaf tip, rapid yellowing and drying up, leaf tip drying and long 0.5~1.5cm, and 2~3cm in severe cases. The disease mainly occurs at two times of the year, one is in early October, when the north wind arrives, and the other is when the weather warms up from March to April when the south wind begins. It was serious in October. Preventive measures should be taken in advance, fertilizer and water management should be strengthened, foliar fertilizer and amino acids should be sprayed in advance, which can effectively control the occurrence of diseases.

⑧ onion thrips should be sprayed with chemicals immediately when the number of 100 damaged plants in the field reaches 50 million. You can choose 10% imidacloprid 2500 times, 40.7% Lesben 1000 times, 40% thistle aphids 1000 times, 20% good year winter 1000 times 2000 times, 5% Regent 1000 times 1500 times. Spraying once every 8-10 days, generally spraying 2-3 times continuously can effectively control the disease.

⑨ Liriomyza huidobrensis can be treated with 10% imidacloprid 2500 times, 40.7% Lesben 1000 times, 5% Yitaibao, 5% carbazem 4000 times, 1.8% mites EC 3000 times.

⑩ onion fly sugar ∶ vinegar ∶ water = 1 ∶ 1 ∶ 2.5 add a small amount of trichlorfon, wine lees mixed with a small amount of trichlorfon, 40% dimethoate 800-1000 times solution irrigated root.

In addition, beet armyworm and Spodoptera litura can be treated with 20% beet armyworm and Spodoptera litura 1000 times solution, 10% elimination suspension 1000 times solution, 5% Yitaibao solution, 5% carbendazim 4000 times solution, 25% diflubenzuron suspension 500 times 1000 times solution, 20% diflubenzuron suspension 1500000 times solution.

Chemical control is best to add the same amount of disinfectants, such as neutral soap powder, neutral washing powder, detergent, starch and so on, in order to enhance adhesion.

5 timely harvest

When the onion grows to a suitable height, the whole plant should be pulled out and put on the market in time to facilitate the robust growth and tillering of conventional plant spacing.

When the spring onions with regular row spacing are suitable for market, ramet harvesting should be carried out in time, that is, 1-2 plants per hole should be left as mother plants, and the rest should be pulled out. When pulling onions, you should pay special attention to protecting the mother plant left behind, and compacting the exposed roots with a small amount of soil. When the soil is slightly dry, water it once. If the onion is not pulled out in time, the onion plant will grow, and the tiller will increase faster, the plant will become thinner and weaker, and the diseases and insect pests will be aggravated, which will affect the commodity quality of the onion.

6 leave the seed

The seeds of red chives in Guangzhou are generally kept in the production fields. At the end of March and the beginning of April, they stop pulling onions, or plant them shallowly in high beds, strengthen management, and begin to squat in mid-late April (that is, bulbs begin to grow into globular shape and no longer tiller). In May-June, when the pseudostem is sagging, the whole plant should be harvested, and after drying (mainly pseudostem and onion skin), hang in a cool place and wait for autumn to sow. If a large number of seeds are left, the onion seeds should not be stacked after harvest, but should be spread out for storage; if they are stacked and stored, they should be turned every 1-3 days.