1) growth process: garlic is cultivated in the field and belongs to asexual reproduction. The growth process of garlic can generally be divided into six stages: germination stage, seedling stage, flower bud differentiation stage of scale bud, garlic moss extension stage, bulb expansion stage and dormancy stage.
The length of garlic growth process varies greatly with different sowing dates. The growth period of spring sowing garlic is short, 90~ 100 days, while the growth period of autumn sowing garlic is 220~240 days. The germination period of garlic generally takes about 10~ 15 days from sowing after dormancy to unfolding of primary leaves. The seedling stage is from primary leaves to undifferentiated leaves. It takes 5-6 months to sow garlic in autumn and only 25 days to sow garlic in spring. The differentiation period of flower bud and scale bud is from the beginning of flower bud and scale bud differentiation to the end of differentiation, which is called "valve-splitting period" in production and generally takes 10~ 15 days. The extension period of garlic moss refers to a period of time when garlic moss begins to extend, which leads to the harvest of garlic moss. This period is the pre-expansion period of scale buds, which lasts about 30 days. The expansion period of scale bud lasts 50~65 days from the end of scale bud differentiation to bulb (garlic) harvest, and the first 30 days overlap with the extension period of garlic moss. Garlic bulbs mature, that is, garlic enters dormancy after harvest, which generally takes about 60 days. The length of dormancy period is related to the variety. The dormancy period of early-maturing varieties is generally about 65~75 days, while that of late-maturing varieties is only 35~45 days.
(2) Requirements for environmental conditions: Garlic has different external environmental conditions in different growth processes.
① temperature
Garlic likes cold environmental conditions, and the suitable growth temperature is 12~25℃. The lowest germination temperature of garlic cloves is 3~5℃, and the germination is rapidly accelerated above 65438 02℃, and the optimum germination temperature is about 20℃. The suitable temperature for seedling growth is 65438 04 ~ 20℃. When the seedling has 4~5 leaves, it can tolerate low temperature above ~ 16℃. The suitable temperature of garlic moss extension period is 15~20℃, and the suitable temperature of bulb expansion period is 20~25℃. If the temperature is too high, the bulbs will stop growing and enter a dormant state.
Garlic also belongs to the green vernalization type. Garlic usually germinates to seedling stage, and in case of low temperature of 0~4℃, it will pass vernalization after 30~40 days.
② Lighting
Garlic is a long-day plant. When the sunshine 1.2 hours or more and the temperature 1.5 ~ 20℃, the terminal buds on the stem disc will turn into flower buds and start bolting quickly.
The development of garlic moss is not only affected by temperature and light, but also related to nutritional conditions. If the petals of seeds are too small, the soil is barren, the sowing is too late, the density is too high, and the fertilizer and water are insufficient, it is possible to form a moss-free garlic or a garlic. In addition, the formation of garlic requires a long period of sunshine. General varieties only differentiate new leaves and cannot form bulbs under short sunlight. However, some early-maturing varieties are not strict with photoperiod.
③ Moisture content
Garlic leaves belong to drought-tolerant ecotype, but the root system is shallow and the water absorption capacity is weak, so in the early stage of vegetative growth, the soil should be kept moist to prevent the soil from being too dry. Especially in the period of flower stem elongation and bulb expansion, the soil should be kept moist to prevent the soil from being too dry. Especially in the period of flower stem elongation and bulb expansion, more water is needed, and the soil is required to be kept moist frequently. In the later stage of bulb development, watering should be controlled to reduce soil moisture, so as to promote bulb maturity, improve storage resistance, and prevent rotten neck (base of pseudostem) from spreading petals due to high humidity, high temperature and lack of oxygen, and garlic skin from turning black and reducing quality.
④ Soil nutrition
Garlic does not require high soil types, but its roots are weak, and loam rich in humus is the best. The soil with loose ventilation and strong water retention and drainage performance is suitable for the growth and development of bulbs, making garlic large and tidy, with good quality and high yield. Garlic cultivated in sandy soil has strong spicy taste, loose texture and is not resistant to storage. The suitable soil pH value is 6 ~ 7. Growth will stop when the root tip of the acid becomes thicker. If the alkalinity is too strong, the seed petals will rot easily, the garlic with small head and single petal will increase, and the yield will decrease.
Garlic likes full-effect organic fertilizer with nitrogen, phosphorus and potassium. Applying humus fertilizer can increase garlic yield. Generally, the fertilization amount per 667m2 is 8.6kg of nitrogen, 7.4kg of phosphorus and 8.6kg of potassium. In the early stage of seedlings, the nutrients stored in the main petals rarely absorb the three elements in the soil.
During the extended flowering period and the mid-bulb expansion period, the roots and leaves grew vigorously, the assimilation and absorption function entered the peak period, and the total absorption gradually reached the highest value. In the later stage of bulb expansion, plants tend to mature, stems and leaves gradually dry up, roots age, and the ability to absorb soil nutrients is relatively weakened. Appropriate amount of nitrogen fertilizer should be applied during the bulb expansion period, and too much nitrogen fertilizer will easily lead to bulb peeling. If the soil contains more sulfur, it can increase the content of propylene sulfide in bulbs and enhance the spicy taste.
3. Main cultivation techniques
(1) sowing date
Sowing in time is one of the important measures to obtain a double harvest of garlic moss and garlic. The determination of cultivation season should be based on the requirements of different garlic varieties, the growth environment conditions at different growth stages and the climatic conditions in various regions.
China's export garlic producing areas are all planted in autumn. When garlic is sown in autumn, the growth period of seedlings is very long. Compared with spring sowing garlic, the yield of garlic and garlic moss is higher. Therefore, all areas and varieties where seedlings can safely overwinter in the open field should be sown in autumn. The average daily temperature suitable for sowing in autumn sowing area is 20~22℃. Before overwintering, the seedlings grow more than 3 leaves, generally 5~6 true leaves are suitable. Generally, the sowing date is in the middle and late September in North China, and in the middle and early September in South China. It is feasible to sow in spring in northeast, northwest and alpine regions. Don't sow in autumn too early, or the plants will easily get old. Soon after garlic begins to hypertrophy, the plant will turn yellow and the yield will drop. Don't sow too late, otherwise the growth period of garlic seedlings will be short, which will affect garlic yield. Garlic should be sown as early as possible in spring, as long as the surface is thawed and ready for operation.
(2) Soil selection and cultivation system
① Soil selection
Although garlic has strong adaptability to soil, it can grow except saline-alkali sand wasteland. However, due to the shallow root system and weak absorption capacity of garlic, in order to achieve the goal of high quality and high yield, there are certain requirements for soil. The soil suitable for planting garlic is sandy loam, which is rich in organic matter, fertile and loose in texture. Sandy soil has weak ability to keep fertilizer and water, and the garlic produced is small and spicy. Garlic growing in sticky soil is small and sharp. Because garlic is strict with soil moisture, it is afraid of both soil drought and waterlogging. Therefore, the selected plot should have irrigation and drainage conditions.
② Cultivation system
Garlic is not suitable for continuous cropping, nor for repeated planting with other Allium plants. Otherwise, the root system is underdeveloped and easy to rot, resulting in weak plant growth, or after the seedlings are unearthed, the leaves gradually dry up, or diseases are prone to occur, reducing yield and quality. Garlic is not strict in the choice of previous crops. When sowing garlic in autumn, beans, melons, eggplant, potatoes, corn, rice and so on should be stubbled. Garlic has a large amount of fertilizer, less fertilizer absorption, more residual fertilizer in the soil, and the root system secretes fungicides, which can prevent various diseases of the following crops and is a good previous crop of the following crops.
Garlic is not only a vegetable, but also a medicine. When a clove of garlic is chewed in the mouth, germs in the mouth can be eliminated. Garlic can also control pests and diseases. Mashing garlic, adding water and spraying these aqueous solutions on cotton can kill cotton aphids with good results.
It turns out that garlic contains a plant bacteriostatic agent-allicin, and its bactericidal ability is almost 100 times that of penicillin! Those harmful staphylococci, streptococci, typhoid bacilli and dysentery bacilli can no longer exert their magic when they meet 1/80000 allicin. Mash garlic and squeeze out the juice. It only takes three minutes to destroy all the cultured bacteria.
In addition, garlic can also reduce gallbladder poisoning, keep the coronary artery unblocked and fight cancer.
Modern research has confirmed that the medicinal active components of garlic are mainly sulfur-containing organic compounds, active enzymes, selenium compounds and peptides. Among them, allicin produced by the metabolism of sulfur-containing organic substances under the action of active enzymes is the main component of garlic disease control. Understanding the medicinal components of garlic and their formation process is very useful for us to eat garlic and choose natural garlic preparations.
Fresh garlic itself does not contain allicin, but the cytoplasm of garlic contains a sulfur-containing organic compound called alliin, and the cell wall contains an alliinase. After fresh garlic cells are broken, alliin produces a series of sulfur-containing metabolites such as allicin and joni aho ene under the action of alliinase. Among them, allicin is the ingredient that produces the spicy taste of garlic, which has strong spicy taste and irritation. Scientific research has confirmed that allicin has strong antibacterial, antiviral, immunity enhancing, blood lipid regulating, cholesterol lowering, anticoagulant, tumor cell inhibiting, blood sugar lowering, liver protection and cancer prevention functions.
Scientific research has also confirmed that garlic is a kind of food rich in selenium, and selenium-containing compounds in garlic can be used to prevent cancer. Garlic also contains a variety of active enzymes, among which superoxide dismutase can specifically catalyze the decomposition of superoxide anion free radicals and has anti-aging effect. Garlic also contains a variety of peptides, which is an anti-tumor active ingredient.
Through a lot of research, the mysterious mechanism of garlic's disease prevention and treatment has been gradually revealed.
People's love for garlic and natural garlic preparations has swept the world. In Britain, the annual sales volume of garlic preparation is about 1 100 million tablets; The United States consumes garlic preparations worth more than 1 billion dollars every year; In Germany, the largest sales volume of drugs is garlic preparation. According to the information published on the website of the University of South Florida, 1998- 1999 garlic preparation ranks first among 10 varieties such as ginseng and ginkgo biloba preparation.
/kloc-In the 9th century, Pasteur first discovered the antibacterial activity of garlic. Since 1950s, Chinese scholars have proved that garlic can inhibit and kill a variety of pathogenic bacteria (staphylococcus, streptococcus, meningococcus, coliform bacteria, typhoid and paratyphoid bacteria, dysentery bacilli, tuberculosis bacilli, pertussis bacilli, Vibrio cholerae, etc. Therefore, garlic is known as a natural broad-spectrum plant antibacterial agent. Even now there are various powerful antibiotics such as penicillin, streptomycin, chlorine and chlortetracycline. However, garlic has no drug resistance and no cross-infection with berberine or sulfonamides, so it still has its unique clinical application value.
The antifungal effect of garlic is more prominent and important, and there is almost no toxic side effect. The research of Xinjiang Institute for Drug Control confirmed that freeze-dried garlic powder tablets had a certain inhibitory effect on Candida albicans, and the minimum bactericidal concentration against Cryptococcus neoformans was better than nystatin. It has obvious therapeutic effect on skin infected by Cryptococcus neoformans. Beijing-Children with leukemia complicated with fungal pneumonia. When other drugs are ineffective, freeze-dried garlic slices can not only cure mold infection, but also improve physical fitness and blood diseases. Shanghai —— An elderly diabetic patient with toe mold infection, after years of using various drugs, asked Xinjiang Medical Insurance Company for oral recovery of freeze-dried garlic slices.
The military hospital 155 used allicin to treat leukemia complicated with stomatitis, and achieved good results.
The antiviral effect of garlic preparation is also very important. 1: 25 garlic diluent can completely inhibit the growth of cytomegalovirus (Ad 169 strain) and has no obvious effect on the growth of normal cells. 0.0 1.5 mg/ml allicin can kill herpes simplex virus. The experiment shows that the order of antiviral action of garlic components is garlic? gt； Allicin > allyl methyl thiosulfinate. Freeze-dried garlic powder tablets can completely release these ingredients in the intestine.