Preliminary study on Prevention of two kinds of diseased garlic in Cangshan garlic

Cangshan garlic is famous for its large garlic head, thin garlic skin, white and neat cloves, spicy and spicy flavor, spicy, sticky and other excellent qualities. In recent years, due to improper planting and management methods, two kinds of morbid garlic have appeared in Cangshan garlic production. One is that garlic produces small garlic leaves (commonly known as braids) at the same time during bolting, which makes it difficult to harvest garlic bolts. affected the yield and quality of garlic bolts. The disease accounts for 5% to 10% of the total garlic. There are two main causes, one is excessive nitrogen fertilizer, and the other is affected by low temperature. The other is the overgrowth of garlic, which neither bolts nor grows garlic, resulting in the extinction of a single garlic, which accounts for 1% or 2% of the total garlic. The cause of the disease may be caused by a variety of virus infection and excessive nitrogen fertilizer.

These two diseases do not occur in large areas or in large areas, but sporadically occur in garlic fields, so the causes are very complex. This situation exists in dozens of garlic districts and 13300 hectares of garlic fields in Cangshan County, and once it occurs, it cannot be treated, so prevention is the most important measure and the only way at present. Over the past few years, through the production investigation of nearly a thousand garlic growers, a set of effective planting prevention measures have been summarized.

1 selection and storage of garlic species

There are mainly three cultivated varieties of Cangshan garlic: Pushu, Brown garlic and Gaojiaozi. Farmers plant more Puke garlic and brown garlic, which have strong growth potential and adaptability, and are more hardy. The disease of tall foot is lighter than the first two, but its adaptability is poor. No matter which variety you plant, you should choose garlic with large head and uniform cloves, 6-8 cloves to make up one end, and strong-growing garlic that is not injured at harvest. After choosing the garlic seed, tie it into a handle and hang it in the sun, don't be exposed to the sun, and don't get caught in the rain. The garlic is sunburned until the stems and leaves become soft and yellow. the outer skin of the garlic has been dried and braided and hung in a dry and ventilated house for storage. It is worth noting that garlic seeds should be stored at 15: 18 ℃ or 0: 7 ℃ 30 days before sowing, and the air relative humidity is 75% 100%. Low temperature and high humidity will lead to the occurrence of morbid garlic.

(2) soil preparation and fertilization

Garlic root system is string-shaped whisker root, the root system is fragile, the vitality is poor, 80% to 90% are distributed in the 15~20cm deep plough layer, like the fertile and loose soil environment, the soil quality is suitable to choose neutral loam. After the harvest of the previous crop, the soil moisture should be ploughed and turned, and the ploughing depth is about 20cm. After ploughing, the soil is fine and flat, so that the soil is fine, the soil is loose, and there is no light and dark. Soil fertility test should be carried out before sowing to achieve balanced fertilization. When the contents of nitrogen, phosphorus and potassium in soil are 140~150mg/kg, 23~47mg/kg and 110~120mg/kg respectively (the content of organic matter in Cangshan garlic field is mostly low), biological organic fertilizer 100~120kg can be applied every 667m2. At the same time, rotten human feces and urine 1500~2000kg can be applied, and chemical fertilizer, especially nitrogen fertilizer, should be applied as little as possible. Ammonium carbonate 40kg, calcium superphosphate 50kg, potassium sulfate 30kg and garlic microfertilizer 15kg should be applied every 667m2. It must be noted that the base fertilizer must be spread evenly.

3 sowing

Before ① sowing, the seeds were selected by breaking the petal, removing the damaged bud tip or rotten petal, yellow petal, moth-eaten and naked petal, and selecting intact and medium-sized garlic cloves as seeds. The larger the clove is, the more likely it is to lead to morbid garlic.

The most suitable sowing date of ② Cangshan garlic is October 1-10, during which the daily average temperature is 16-17 ℃, and the deep ground temperature of 5cm is about 18 ℃. Be sure to choose sunny days to sow, do not blindly sow in advance.

The planting density of ③ is 40 000 ~ 50 000 trees per 667m2, row spacing 17~19cm, plant spacing 5.5~6.5cm. The planting density is higher than the traditional density. The ditch depth is about 10cm, the sowing depth is 6~7cm, after sowing, the border surface is flat, and the thickness of soil cover is 4~5cm, which is thicker than the traditional experience, 1~2cm, and irrigate the head all over in time. After watering, the plastic film is covered 1 or 2 days later than the traditional experience, and both sides are compacted with soil.

4 field management

① Cangshan garlic is generally cultivated with plastic film mulching, and the seedlings must be released at the right time. Once the phenomenon of budding and arching film is found, the garlic seedlings should be released in time, and the seedlings should be watered thoroughly after finishing the seedlings.

② uses artificial weeding and does not use herbicides at any time.

After ③ entering winter, when the temperature is lower than 0 ℃, pour frozen water in time, cover some weeds, keep warm and protect seedlings, and survive the winter safely.

After ④ turned green the following year, pour the green water and apply urea 15kg/667 square meters with the water. At this time, we must apply less nitrogen fertilizer, otherwise the disease will be aggravated. At the same time, we should guard against the cold snap in early spring, in case garlic is frozen and morbid garlic occurs seriously.

5 other measures

① Cangshan garlic is best rotated with @ # @ 245 garlic, and can be interplanted with spinach and other crops.

② uses chemical control as little as possible in the prevention and control of garlic diseases and insect pests, and can select high-quality virus-free garlic species, strengthen field management, improve plant disease resistance, remove disease residues in time, and reduce the source of disease in the field.

Garlic fields with aphids in ③ should be controlled in time in order to cut off the virus transmission vector.

The above cultivation measures are only part of the summary of production experience, which can effectively reduce the occurrence of two kinds of sick garlic.