Control techniques of abnormal growth of garlic

The abnormal growth of garlic mainly includes two kinds of garlic secondary growth and onion type garlic. Secondary growth phenomenon, also known as garlic degenerated leaf regrowth phenomenon, commonly known as horsetail garlic, refers to garlic in the garlic stalk exposed at the same time, along with a circle of garlic leaves around the garlic stalk, these leaflets grow around the garlic stalk, but the growth point of the new garlic cloves does not have any germination phenomenon. This abnormal phenomenon makes garlic neither seed nor edible, which seriously reduces the commercial and economic benefits of garlic.

The main reasons for the secondary growth of garlic are as follows:

① selected garlic varieties which were not suitable for planting in this area; ② advanced or delayed the sowing time of garlic; 30 days before ③ sowing, the storage environment of garlic was not suitable; in the process of ④ planting, nitrogen and phosphorus fertilizer were applied, and potassium fertilizer was lack.

Onion garlic is commonly known as bread garlic, the garlic plant is very strong before harvest, but the garlic has undergone abnormal changes, after harvest, there are only layers of garlic skin, no garlic cloves or garlic cloves the size of soybeans. Once onion garlic appears in production, it does not have any commodity value or edible value.

The main reasons for the phenomenon of onion garlic are as follows:

In the process of planting ①, excessive application of nitrogen, phosphorus, potassium and other base fertilizers; ② soil water content is too large; ③ watering is not timely

The harm of abnormal growth of garlic is very serious, once this phenomenon occurs in production. There are no remedial measures, therefore, the whole process control should be done well in the process of garlic cultivation and management.

Land selection and preparation

Garlic should be planted in areas with high topography and good drainage, in which it is better to grow loam with fertile soil, strong water retention and drainage capacity and 1.71% organic matter content or light clay loam. Garlic likes cool, wet and dry, and the better soil plough layer is beneficial to the growth and development of garlic root system. When the soil is too sticky and heavy, it is easy to clump with the soil by hand, which can lead to the formation of onion garlic. The results showed that 26.06% onion garlic could be formed when the relative water content of soil reached 90% to 100%. In order to control the abnormal occurrence of garlic, the land planted with garlic should be ploughed early to turn ridges, activate the soil, increase soil permeability, and promote the development of garlic root system and bulb hypertrophy.

Before sowing, sufficient basal fertilizer should be applied in combination with soil preparation. Garlic is a shallow root crop. Only by applying sufficient basal fertilizer at one time can we fully meet the nutrient demand of garlic and achieve the purpose of controlling abnormal growth.

The method of formula fertilization should be adopted to apply base fertilizer. When planting in autumn, 5000 kg of high-quality ring fertilizer, 20 kg of nitrogen fertilizer, 10 kg of phosphorus pentoxide and 15 kg of potassium oxide were applied per mu. It should be noted that in the process of fertilization, excessive application of nitrogen, phosphorus and potassium will lead to onion garlic. Experiments show that when the amount of nitrogen fertilizer and phosphorus pentoxide per mu is up to or more than 40 kg, can induce the emergence of a large number of onion garlic.

After the basic fertilizer is applied, the soil should be deeply ploughed to loosen the soil, and the machine deep ploughing method is usually used in production, and the ploughing depth is generally about 25 centimeters. It is necessary to rake flat and fine, the soil is flat, the soil is loose and solid, and there is no obvious large piece of soil. reach the standard of "even, loose, broken and clean".

The quality of soil preparation is very important, which is directly related to the quality of film mulching and the effect of seedling protection. If the soil preparation quality is poor, the soil block is large, and the soil surface is uneven, the plastic film will not be covered strictly, leaving a large gap, which not only promotes the breeding of weeds, but also affects the moisturizing and heat preservation effect of the plastic film, resulting in uneven seedling emergence and abnormal growth of garlic.

After ploughing, the length of the bed is determined according to the location of the water source, and it is made into a bed with a length of 40-50 meters and a width of 1.5-2 meters. Try to make the width uniform, the border surface flat and the border line straight.

Selected improved varieties

In order to ensure the yield and quality of garlic and avoid the occurrence of abnormal garlic, the seed cloves should be carefully selected before sowing. The selection of seed cloves should be carried out in the field after the garlic is harvested. From the harvested garlic plants, the large diameter garlic with a single weight of more than 5 grams is selected, the leaves are disease-free, the color of the garlic skin is the same, fat and round, and the outer garlic cloves are uniform in size for seed storage. remove garlic cloves with disability and disease spots and some over-small cloves.

What needs special reminder here is that garlic varieties suitable for planting in this region must be selected, because an important reason for the occurrence of garlic secondary growth phenomenon is heredity. If garlic varieties that are not suitable for planting in this region are selected, it will greatly promote the occurrence of secondary growth phenomenon.

After the garlic seed is selected, it should be stored in a cool and ventilated place, and when it is about to be sown, it should be treated with seed cloves.

Garlic is widely planted in China, and the varieties are relatively complete, and each region has its own suitable planting varieties. However, in order to ensure the yield and quality of garlic and avoid the occurrence of abnormal garlic, the seed cloves should be carefully selected before sowing.

Seed petal treatment

In production, garlic seeds are generally treated by refrigerating garlic seeds. 10 to 15 days before sowing, garlic seeds are put into a constant temperature storage. The temperature in the constant temperature storage is kept at about 0 ℃, and the relative humidity must be kept at 60% 75%. In order to break the dormancy period of growing garlic. If the garlic is refrigerated in an environment with an air relative humidity of more than 75%, the secondary growth of garlic will be significantly improved.

During cold storage, ventilation should be maintained in the warehouse, and there are no other toxic pollutants in the warehouse, so as to prevent the garlic cloves from mildew and deterioration. In order to avoid pollution caused by walking in the warehouse, another operating room can be set up outside the warehouse if conditions permit, and closed-circuit television can be used to monitor and manage the warehouse.

After cold storage treatment, garlic seeds need to be broken before sowing, and the petal breaking work should not be done too early to prevent drying and water loss and affect seedling emergence. The method is to peel off the stem plate of garlic and remove the leathery skin outside the cloves. After the garlic cloves are broken, you can sow the seeds.

Suitable time for sowing

The best sowing time for garlic is between mid-late September and early October. In northern China, the best sowing time for garlic is five days before and after the National Day, that is, from September 25 to October 5. Even if the most suitable sowing time for garlic in southern China should not exceed October 20, sowing after October 20, it is easy to induce the secondary growth of garlic.

When sowing garlic, use the trench opener to open the sowing ditch according to the standard of row spacing of 17 centimeters, keeping the ditch depth and width at about 5 centimeters. The ditch should be of the same depth and the ditch line is straight. after opening the ditch, spread the garlic seeds evenly on the ditch surface, and then sow it into the ditch, this method saves both time and effort, and can flexibly control the progress of sowing.

Special attention should be paid to the same depth of ditching, sowing and soil covering, so as to facilitate the normal growth and development of garlic seedlings and reduce the probability of abnormal phenomena of garlic.

Special attention should be paid to the insertion mode of garlic cloves in garlic sowing. Normal garlic cloves generally have three sides, one arc on the back, two faces of basically the same size on both sides, and the direction of garlic leaves is perpendicular to the dorsal-ventral line of garlic cloves. Therefore, when placing garlic cloves, the ventral dorsal connection should be parallel to the row direction, and the garlic cloves should be inserted into the soil according to the plant spacing, slightly exposing the tip, so that the curved surface of the garlic cloves are facing in the same direction, which is beneficial to increase the solar radiation, thus accelerating the germination speed of garlic and reducing the probability of abnormal phenomena.

When sowing, the plant spacing is kept at about 15,16cm, and generally at about 25000 plants per mu. Sowing too early, due to high temperature, slow germination of garlic cloves, long seedling emergence period, low seedling emergence rate, overgrowth of seedlings before winter, decrease of cold resistance, premature senescence of plants, weakening photosynthesis and nutrient accumulation of garlic bulbs, garlic became smaller, resulting in secondary growth of garlic. Sowing too late, the seedlings are small during overwintering, the vegetative growth period is short, the accumulated nutrients are relatively reduced, the cold resistance decreases, and it is easy to be damaged by freezing, which leads to the decrease of the number of garlic cloves and garlic cloves, and also induces the secondary growth of garlic. After sowing, cover the soil by 1.5 cm, and then water it. The plot should be fully watered thoroughly, and 100 cubic meters per mu should be watered without leakage. This can not only meet the needs of garlic planting, but also control the occurrence of garlic anomalies.