Peppermint is one of the commonly used traditional Chinese medicines, which is widely distributed in China, mainly distributed in Zhejiang, Jiangsu, Hunan, Sichuan, Guangdong, etc. south of the Yangtze River, and also distributed in Yunnan, Fujian, Hebei, Henan, Shandong and other places. At present, Anhui, Hubei, Shandong and Sichuan are the main production areas.
Peppermint, also known as su mint, fragrant peppermint, etc., belongs to the perennial herb of the family Lipaceae, and is used as a whole herb for medicinal purposes. Mint oil and menthol brain processed from mint are not only important raw materials for medicine, food, spices and other industries, but also important export foreign exchange earning products. As one of the main cash crops, farmers learn to grow and can obtain excellent economic benefits.
<h1 class= "pgc-h-arrow-right" > botanical properties of peppermint</h1>
Peppermint is 30-100 cm tall and has horizontal creeping rhizomes, with slender roots in the lower sections of the stem. The stem is generally erect, with four grooves, multi-branched, sometimes single; the upper part is inverted with slightly soft hairs, and the lower part is only slightly soft hairs along the edges. The leaves are paraphyletic, oblong lanceolate to oblong, 3–5 cm long and 2–3 cm wide, sharply pointed or sharply pointed at the apex, wedge-shaped to nearly rounded at the base, with coarse tooth-like serrations at the edges above the base, often with micro-soft hairs along the veins on both sides, and the rest of the parts are nearly hairless.
<h1 class= "pgc-h-arrow-right" > second, mint requirements for the growing environment</h1>
1. Soil requirements
Peppermint is relatively adaptable, preferring deep soil layers, loose soils, loams and sandy loams containing organic matter, and is suitable for planting in soils with pH values of 6-7.5. If the soil is too sandy, too sticky, too heavy salinity, and too high groundwater level, it is not suitable for planting mint.
2. Temperature requirements
Peppermint has stricter temperature requirements, spring ground temperature needs to be above 5 degrees, can die germinate seedlings, seedlings can tolerate low temperatures of minus 5-8 degrees, the suitable temperature during the growth period is 20-30 degrees, the growth period needs to ≥ 10 degrees of accumulated temperature at 2200 degrees, in the late growth period of mint, the temperature difference between day and night is large, which will help promote the accumulation of essential oils in the plant and improve quality.
3. Moisture requirements
Peppermint prefers a warm and moist environment. During the growth period, the amount of branches and leaves is large, the water is more, and the later stage requires less water, we should appropriately irrigate to effectively avoid the phenomenon of plant greed, growth, lodging and fall off and rot of the middle and lower leaves, and reduce the yield. Also, the earlier the harvest, the better.
4. Light requirements
Peppermint is a typical long-day crop. Throughout the growth period, adequate light and dry weather help to reduce leaf shedding, facilitate normal growth of peppermint and essential oil production and storage.
<h1 class= "pgc-h-arrow-right" > third, high-yielding cultivation techniques of peppermint</h1>
1. Variety selection
At present, the most common cultivars of peppermint are two, green stem and purple stem purple vein. The upper part of the stem of the green stem is cyan, the leaves are short, ovoid and shiny, the plant is short, there are many branches, and the high yield characteristics are very obvious. For purple-stemmed purple-veined varieties, the stems are dark purple, the leaves are oblong, serrated and dense, there are few branches, and the yield is significantly lower than that of the green stems, but the brain content of essential oils is 2%-5% higher than that of the green stems.
2. Fertilize the land
Peppermint is suitable for choosing loam soil with fertile soil, flat terrain, convenient drainage and irrigation, sufficient sunshine, loam soil or sandy loam soil that has not been planted with peppermint within 2-3 years, over acidic or alkaline soil, barren sand soil and land with insufficient sunshine and drought and flooding cannot be planted. Before planting, we need to cultivate deeply, apply 2000-2500 kg of decomposed farm manure as the base fertilizer per mu of land, and then make a high furrow of 1.5 meters wide and 15 cm deep, and open a drainage ditch, and the width of the ditch is 30-40 cm.
3. Breeding method
(1) Seedling propagation
Good-growing, pest-free plots are selected as planting grounds. Immediately after the autumn harvest, we need to weed and topdress 1 time immediately. In April-May of the following year, the seedlings are plucked and transplanted at a height of 15 cm. The transplantation site is dug according to the row spacing of 20 cm and the plant spacing of 15 cm, and generally 1-2 seedlings are planted per hole. After planting, it is necessary to cover the soil and press it tightly, and then apply thin human and animal manure water to fix the roots. The transplanting of peppermint is generally most suitable to be carried out before the Qingming Dynasty, which can effectively increase leaf yield and increase oil production and brain volume. It should be noted that it must not be postponed until after the Dragon Boat Festival, otherwise the yield will drop significantly.
(2) Rhizome propagation
From late October to early November of each year, on the leveled furrow surface, the horizontal trench is carried out according to the row spacing of 25-30 cm, and the depth is about 10 cm. Then, dig up the rhizomes from the reserved planting ground, select the white, stout, short internodal sections, cut into small sections about 10 cm long, and then plant them into the ditch according to the standard of 15 cm spacing. After planting, apply thin manure water in time and cover the fine soil to rake and compact. Generally, one acre of field is about 100 kg of white tender new rhizomes.
4, Ota Management
(1) Weeding in medium cultivation
When the mint seedling height is 9 cm, we must cultivate the weeds once in time. After the first harvest in July, we should carry out a second tillage in time to effectively remove some of the overcrowded rhizomes. In the spring of the second and third years, when the seedling height is 12-18 cm, combined with weeding, remove the overcrowded seedlings,
(2) Topping
The heart of peppermint should be removed from the top two pairs of young leaves as appropriate, the heart of peppermint needs to be adapted to local conditions, and the single kind of peppermint with a larger density is best not to pick the heart, and the mint with small density or weak growth needs to be hearted in time to effectively promote the growth of side branches and increase the density.
(3) Topdressing
The topdressing of peppermint should be based on nitrogen fertilizer, the first topdressing should be carried out when the seedling height is 5-10 cm, urea is applied to 15-20 kg per mu of land, the second topdressing needs to be carried out when the height of the mint seedling is 20 cm, 10 kg of urea is applied to one mu of land, the third topdressing needs to be carried out after the head knife harvest, each mu of land is applied urea 15-20 kg, each fertilization needs to be applied deeply in the inter-row ditch, and cannot be directly applied to the root of the plant.
(4) Watering
During the growth of peppermint, we need to keep the surface moist frequently. In times of drought, we should irrigate water in time, and it is most appropriate to pour small water. In the summer and autumn, when there is a lot of rainfall, we need to remove water from the field to prevent the rhizomes from suffocation and death.
5. Pest control
(1) Peppermint spot blight
This disease, also known as white star disease, is a semi-known fungus that mainly harms the leaves. Generally occurs in May and October of each year, the leaf spots are small and round, showing dark green, and then gradually expand into grayish brown, the center is grayish white, white star-shaped, with black dots on it, and gradually withered and fell off.
Prevention and control methods: The first is to rotate crops every other year. When we find sick leaves, we should remove and burn them in time. In the early stage of spot blight, we can spray 12% green milk copper emulsion 500-800 times liquid or 50% succinate copper wettable powder 500-1000 times liquid, sprayed once every 10-15 days, and should be continuously controlled 2-3 times. Stop applying the drug within 20 days before peppermint harvesting.
(2) Mint rust
The pathogen of peppermint rust is a basidiomycete in fungi that predominantly harms leaves and stems. It is susceptible to illness in May and June of each year when it is rainy or too dry. Orange-yellow powdery summer spore piles appear on the back of the leaves at first, and at the end of growth, the plant gradually produces black-brown powdery winter spore piles. When the disease is severe, the leaves will wither and fall off, resulting in the death of the whole plant.
Prevention and control method: In the early stage of the disease, we can spray 15% triazolone wettable powder 1000-1500 times liquid, 50% weeds rust emulsion 800-1200 times liquid, 50% sulfur suspension 300-800 times liquid, sprayed once every 15 days or so. Spraying should be stopped within 20 days before the official harvest.
(3) Small land tiger
This pest belongs to the Lepidoptera noctuidae family and mainly harms the seedlings of peppermint. In the spring, the larvae bite the seedling stem, which is easy to cause a lack of seedlings.
Control method: remove weeds in the field in early spring to prevent adult tigers from laying eggs; then there is sweet and sour booby trap, with 6 parts of sugar, 3 parts of vinegar, 1 part of white wine, 1 part of 90% of enemy insects, and placed in the field to trap adult insects. When the insect pest outbreak is large-scale, we can spray control with 2.5% cypermethrin and 20% cypermethrin 2000-3000 times liquid, and use the drug 2-3 times continuously. Stop the application within 20 days before harvesting.
(4) Silver-striped nocturnal moth
It belongs to the lepidoptera Noctuidae and is mainly harmful to leaves and flower buds. The silver-striped nocturnal moth mainly feeds on the leaves of the larvae, which is easy to cause a lack of holes. Prevention and control methods: We can use 24% Marigold 1000-1500 times liquid, 30% dioprethroid 2500-3000 times liquid spray prevention, the agent is used alternately, the prevention and control effect is better.
<h1 class="pgc-h-arrow-right" > four, four key periods of mint growth</h1>
1. Seedling growth period
Mint rhizomes germinate at 2-3 degrees, during which time we need to ensure adequate moisture and the right temperature. If the field density is small or the growth of mint is weak, when the mint plant begins to branch, we can pick the heart treatment to promote the growth of the side branches of the mint plant, increase the field side branch density, and then increase the total yield of peppermint. The toppings should be carried out at noon on a sunny day.
2. Branching and flourishing period
The optimal temperature during this period is 15-30 degrees. In this period of plants a large number of branches, transpiration increased, we should ensure sufficient water supply, an acre of land needs to be applied urea 10-15 kg, need to pay special attention to this time can not continue to pick the heart.
3. Flowering period of pregnant buds
This period is a critical period to ensure product quality and yield. We need to ensure adequate light, which plays an important role in increasing peppermint oil production. One acre of mint field was increased by 15-20 kg of urea, the soil moisture content was maintained at 75%-85%, and the water was stopped 10-15 days before harvesting. One acre of land was sprayed with 200 grams of potassium dihydrogen phosphate and 100 grams of urea on the foliar surface, and sprayed twice in a row to fully extend the life of the leaves.
4, Dormant winter season
When the temperature drops below 0 degrees, the aboveground part shrinks and dries up, and the underground rhizomes gradually enter the dormant overwintering period. During this period, the soil moisture content was maintained at about 85%, and a layer of organic fertilizer was applied after the upper leaves dried up, laying a good foundation for stable and abundant production in the coming year.
Conclusion: Mint is planted in North China and can be harvested twice a year, the first time from late June to early July, no later than mid-July; the second harvest is generally in early October. Conditional plots, we can take the way of mechanical harvesting. For the harvested mint, we need to spread it on the ground without direct light, dry it to 70% or 80%, and then gradually tie it into a small handle and continue to dry in a cool and ventilated place. Mint has high economic value, is more suitable for farmers to plant, is a good way to get rid of poverty and get rich.