Rejuvenation measures of garlic with short and big head

Tongling County, Anhui Province is located in the middle and lower reaches of the Yangtze River. Garlic, as one of the "Tongling eight treasures", has a long history of cultivation, especially the local variety short and big head, unique flavor, is favored by people. Due to a variety of reasons, there has been serious variety degradation, the per unit yield of garlic stalk and garlic head has decreased greatly, the quality has become worse, and there have been a large number of bad characters such as single garlic, single garlic and compound garlic.

(1) the causes of sexual degradation of short and big-headed species.

1.1 long-term asexual reproduction

Dumatou has been propagated by garlic cuttings in Tongling area. Due to lax seed selection and improper methods, small valves, diseased valves and damaged valves are often used as seeds. Many factors make the offspring retain the good characters of their parents as well as the metamorphosis of their parents, and the long-term accumulation leads to serious sexual degradation of the dwarf species.

1.2 improper cultivation methods

The planting density is too high, resulting in individual malnutrition and poor maturity of the remaining plants, resulting in the deterioration of the quality and characters of garlic; due to the high price of garlic bolting in the early stage, vegetable farmers harvest bolts too early, resulting in excessive nutrient consumption of garlic; improper use of tools and methods, often cause bulbs to be damaged.

1.3 improper cultivation and management

Due to long-term continuous cropping, less application of farm manure and other organic fertilizer, excessive application of chemical fertilizer, resulting in changes in soil physical and chemical properties. In the seedling growth period, due to lack of fertilizer and water or damage to cotyledons, the plant growth is thin, resulting in a small growth at the beginning of bulb formation, resulting in the emergence of single-headed garlic or small garlic.

1.4 influence of climatic conditions

Due to the weather, the late spring cold often occurs in the bulb expansion period of garlic, the days of low temperature are too many, and the growth of garlic leaves is small, resulting in single garlic, less garlic or compound garlic.

(2) measures for sexual rejuvenation of short and big-headed species

2.1 intensive cultivation

It is better to choose sandy loam with deep soil layer and rich organic matter. Apply sufficient basic fertilizer one week before cutting: apply a small amount of urea 20kg, potassium chloride 20kg, potassium dihydrogen phosphate and a small amount of rotten cake fertilizer 150kg or mature human feces and urine every 667m2, spread evenly in the field, turn the soil deeply and rake the field flat.

2.2 tissue culture

The asexual reproduction of short and big head has been successfully carried out under the auspices of Tongling Agricultural Science Research Institute. Using stem tip and root tip growth point as tissue culture materials, virus-free seedlings were cultivated, planted in the field and propagated under aseptic conditions.

2.3 strict selection of species

Before harvest, the plants that have harvested garlic bolts and are healthy and disease-free are selected to leave seeds. When the garlic leaves begin to turn yellow and wither, step on the stem and let it ripen for 3 days or 4 days. During harvest, the round, disease-free and damage-free plants of garlic were selected and dried together with the aboveground parts for 1-3 days, then bundled into bundles and stored in a cool place. During sowing, the round, large, disease-free and pest-free garlic is selected again, peeling off the garlic skin and removing the curved and too small cloves.

2.4 aerial bulb propagation

The individual size of the aerial bulb is small, and it is not necessary to discard it in the first year after sowing. Only by sowing garlic in the second year can the garlic be rejuvenated and produce normal high-quality garlic and garlic bolts.

2.5 timely topdressing

The use of garlic fertilizer should be heavy before and light after. In the process of garlic leaf growth, fertilizer and water management should be strengthened, mainly applying more fertilizer before overwintering. In addition, we should also grasp two main stages of topdressing: one is to promote seedling fattening. After the spring is warm, nitrogen fertilizer and potash fertilizer should be applied again to promote the growth of garlic leaves in the early stage. After the garlic begins to expand, it is carried out to promote the expansion of the bulb. Excessive manure should be avoided when topdressing so as not to cause diseases and insect pests.

2.6 improve cultivation conditions

Choose loose and fertile soil cultivation, appropriate sparse planting, expand the nutritional area of the plant, try not to select and collect seeds in the continuous cropping field.

2.7 change the mode of cultivation

Using plastic film mulching, cutting can be carried out in the middle and late October and plastic film mulching in the middle and last ten days of November. Due to the inconvenience of topdressing fertilizer in the later stage, fertilizer should be put in at one time, and then ploughed and planted in the border. Herbicides can choose Acetochlor, etc., and finally cover and press the film, which can increase temperature and preserve soil moisture and improve microclimate.