Cultivation techniques of mint

Peppermint, alias Rendan grass, is a perennial herb of mint genus of Labiatae, which is distributed all over the country. It has the functions of dispelling wind and heat, clearing the leader, penetrating rash and so on. Its tender stems and leaves can be eaten cold, heat-clearing and detoxifying, and its taste is cool and refreshing. It is a kind of green leafy vegetable with good development prospect for both medicine and food.

I. Botanical characteristics

Plant height 30--80cm, the whole plant has a cool aroma. Rhizome creeping, white. Aboveground stems prostrate or erect, green or purple, square, hollow, inverted puberulent and glandular punctate. Leaves alternate, ovate or long elliptic, margin serrulate, both surfaces sparsely pilose and yellow glandular dots. Cymes axillary, Corolla reddish purple, 2-lipped. Nutlets 4, ovoid. The florescence is 8-October, and the fruiting period is 9-November.

2. Ecological habits

Peppermint is a shallow root plant. Most of the rhizomes are concentrated in the range of 15cm on the surface of the soil, and the horizontal distribution is about 30cm. Both rhizome and aboveground stem have strong germination ability and are used as asexual propagation materials in production. Peppermint has strong adaptability to environmental conditions and can grow in areas below 2100m above sea level. More shade-tolerant, can be intercropped with other crops, exuberant growth, good quality, but like sufficient sunshine, warm and humid environment. The suitable temperature for plant growth was 20 ℃ 30 ℃, and the underground rhizome could survive the winter safely under the condition of-30 ℃-20 Mel.

III. Key points of cultivation

1. Land selection and land preparation: choose sandy loam soil which is sunny, flat, fertile and convenient for drainage and irrigation. Farm manure 4000kg was applied per mu, and 60kg compound fertilizer was applied as base fertilizer. Ploughing, fining and raking are made into 1 Murray 1.2m wide beds.

2. Propagation methods: in production, rhizomes are mainly used for propagation, and seedlings can also be used for propagation. Most of mint is cultivated in open field, and protected field cultivation or both open field and protected field cultivation can be adopted in the north. The cultivation season depends on the local climate and can be cultivated in the frost-free season. The protected field can be produced every year, and the open field in the north can be cultivated from April to October. Rhizome propagation: from late October to early November, dig up the rhizome from the planting land, select the white, sturdy, short Internode, cut into small segments of 10cm, and then plant into the deep trench of pre-dug 10cm, row spacing 25--30cm, plant spacing 15cm. After planting, cover with fine soil and rake flat and compacted. Seedling propagation: select fields with sturdy plants, consistent growth and no diseases and insect pests as seed plots. After autumn harvest, immediately ploughing, weeding and topdressing once. In the first ten days of April of the following year, when the seedling was high and 15cm, the seedlings were pulled out and transplanted. Two seedlings were planted in each hole according to row spacing 20cm and plant spacing 15cm. After planting, the soil is compacted, and then poured with thin dung water.

3. Field management: after emergence, keep the field moist and free of weeds. Small water is often watered. If there is stagnant water, it should be eliminated in time. In order to prevent the branches and leaves from shading each other, it is necessary to guide the growth direction of the above-ground stem and the underground stem in time, so that it will not be crowded. Seedling height 15cm and after each picking should be timely topdressing, in order to promote the occurrence of new shoots, generally mu manure urine dilute or urea liquid 1500kg. It should be watered in time after each fertilization.

4. Pest control: rust: harm to leaves and stems, frequent occurrence in rainy season. In addition to strengthening the field management and improving the ventilation and light transmission conditions, the prevention and control methods can be sprayed with 25% trimethoprim 1000 Mir 1500 times liquid blade spray. Spot blight (also known as white star disease): damage to leaves, occurred in May-October. In the early stage of the disease, remove and burn in time or spray with 75% chlorothalonil 500 Mel 700 times liquid. The main pests are small land tiger and Spodoptera litura. The small land tiger can spray the rhizosphere with 40% chrysanthemum horse EC and chrysanthemum EC 2000Mel 3000 times, or irrigate the roots with 40% methyl isosaliphate 1000 times solution. Spodoptera litura can be sprayed with 50% Yitaibao EC 30--60ml per mu or 1000 times of 50% fenitrothion.

4. If the harvest is in the area with suitable conditions, it can be planted for 1 time and harvested for 2 consecutive years. Generally, when the height of the main stem is about 20cm, the tender stems and leaves can be harvested for consumption. It can be picked all the year round in the southern region, and the yield is the highest and the quality is the best in August when the climate is suitable, with a harvest interval of 15 murmurs and 20 days. In the northern region, protected cultivation in winter can also achieve the purpose of annual supply. Medical use is often harvested twice during the growing period, the first time (head knife) is six days before the summer festival, when Ye Zhengmao is in full bloom and the flowers are not yet in bloom, the ground parts are cut; the second time is between the Autumn Equinox and Cold Dew, when the flowers are in full bloom and the leaves have not yet withered. The medicine should be used for the second harvest.

Fifth, seed retention technology peppermint is easy to degenerate, so we should do a good job of seed retention and seed selection. The common methods are as follows: 1. For the fields with only a small amount of mixed degradation, when the seedlings were high 15cm in late April or two-knife peppermint 15cm in late August, wild species or other hybrid species were pulled out by root twice, and inferior seedlings and diseased seedlings were pulled out at the same time for seed retention. 2. Seed should be kept after stubble. In late April, robust and non-degraded plants were selected in the field and transplanted to the reserved field according to the row spacing 15cmx20cm, so as to strengthen the management and cultivate them to dig at the beginning of winter. 70% of the white rhizomes of 80% of the plants can be obtained for planting.