How to cultivate fennel well? Detailed explanation of the key points of planting techniques
Both large fennel and small fennel are commonly used seasonings, and are essential when cooking fish, stewing meat, and making braised foods. Because they can remove the foul odor from meat and restore its fragrance, they are called "fennel". Large fennel is star anise, whose scientific name is "star anise". The seed fruit of small fennel is a seasoning, and its stems and leaves are also aromatic, often used as filling for foods such as buns and dumplings. The main component they contain is fennel oil, which can stimulate the gastrointestinal nerves and blood vessels, promote the secretion of digestive juices, increase gastrointestinal peristalsis, and expel accumulated gas, so it has the effects of strengthening the stomach and promoting qi; sometimes gastrointestinal peristalsis decreases after excitation, thus helping to relieve spasms and reduce pain. Also known as fennel seed, small fennel, fennel, huai xiang, xiang si cai, small fennel.
Morphological characteristics of fennel
Perennial herb, 40-200 cm tall, the whole plant surface has a powdery bloom, hairless, with a strong aroma. Stem upright, smooth, gray-green or pale white, branched. Three to four times pinnately compound leaves, the final leaflets linear, 4-40 mm long, about 0.5 mm wide; petiole about 14 cm long, the base forming a sheath that clasps the stem. Compound umbel terminal; total peduncle 4-25 cm long, both involucre and involucel absent; rays 8-20, unequal in length; flowers small, yellow; no calyx teeth; petals 45, broadly ovate, the upper part curled inward, slightly concave; stamens 5, longer than the petals; ovary inferior, 2 locules, styles 2. Also schizocarp oblong, with 5 raised ridges, flowering period June-July, fruiting period September-October.
Small fennel is a long-day, semi-cold-tolerant, drought-tolerant, cool-loving dicotyledonous spring crop, relatively drought-tolerant but not waterlogging-tolerant. The growth period after emergence is 65-85 days. The growth process is fast, entering the initial flowering stage 35-45 days after emergence, flowering in early to mid-May, fruiting from late May to early to mid-June, and harvest period in mid-June. Conventional plant height 30-55 cm, the stem shows false dichotomous branching. Leaves alternate, the leaf blade is a ternately parted leaf, with a narrow lanceolate leaf sheath. The umbel diameter is 1-2 cm, white or bluish-white, with 5-7 single flowers, the schizocarp is oblong-ovate, 5-8 mm long, 2-3 mm wide, containing two slightly yellow seeds.
How to cultivate fennel well?
1. Land selection and preparation. Fennel has a strong root system, is drought-resistant and afraid of waterlogging, so it should be planted in deep soil, with good salt removal. It should be planted in sandy loam or light sandy loam with strong permeability and good drainage; the previous crop is preferably barley, wheat, melons, beans, etc., and continuous cropping should be avoided. After the previous crop is harvested, plow and level it in time, and irrigate enough bottom moisture. Fennel seeds are small, and the seedlings after germination have weak soil-piercing ability, so the land should be finely prepared. Generally, after the soil thaws in early spring in March, plow and level it in time, cut the high and fill the low, to achieve fine, crumbly, loose and soft, level as a mirror, ready for sowing.
2. Apply enough base fertilizer. Fennel has a long growth period and a high fertilizer requirement, and likes phosphorus and potassium fertilizer. Fertilization should be mainly base fertilizer. Before sowing, combined with land preparation, apply 1000 kg of high-quality organic fertilizer, 50 kg of rare earth phosphate fertilizer, 20 kg of urea, and 6 kg of potassium sulfate per mu, evenly mixed and applied 10 cm deep into the soil as base fertilizer.
3. Soil treatment. In mid-March, combined with land preparation, use 100 cm of trifluralin or dinitramine emulsifiable concentrate per mu, diluted with 30 kg of water, evenly sprayed on the ground surface on a windless day, and harrow the ground in time so that the soil and pesticide are evenly mixed, with a harrowing depth of 6--8 cm. After harrowing, level the ground surface in time, preserve moisture and wait for sowing.
4. Sow early at the right time. Select plump seeds, bright in color, free of diseases and insect pests, carry out manual selection, remove debris, and before sowing mix the seeds with phoxim and wait for sowing. In the Hexi region, it is generally suitable from late March to mid-April. Use 3 kg of selected and treated seeds per mu, with a row spacing of 30--40 cm and a plant spacing of 12--15 cm for hole sowing, sowing about 10 seeds per hole; mechanical drilling can also be used, with a sowing depth of about 2 cm, and after sowing smooth the ground surface.
5. Loosen the soil and weed. Fennel seedlings have weak soil-piercing ability and slow growth at the seedling stage. Before and after emergence, promptly break the crust to help the seedlings emerge. After the seedlings emerge and rows are visible, weed and release the seedlings in time. At the seedling stage, cultivate and weed in time to keep the field loose and clean, so as to facilitate growth and development.
6. Thin and finalize the seedlings. When fennel grows 2--3 true leaves and the seedlings are 4--5 cm tall, thinning can be carried out, with a plant spacing of 12--15 cm, keeping 2--3 seedlings per hole. When there are 4--5 true leaves and the seedlings are 6--8 cm tall, finalize the seedlings, keeping 1 seedling per hole, and it is suitable to keep 1.20--1.50 million seedlings per mu. Thinning should be early, and finalizing should be ruthless; double seedlings must not be kept, so as to help form strong seedlings.
7. Reasonable fertilization. Combined with irrigation, at the 1st--2nd watering, apply 8--10 kg of urea per mu as topdressing according to the seedling condition. During the flowering and grain-filling period, insist on foliar topdressing, spraying dipotassium phosphate etc. 3--4 times.
8. Irrigate at the right time. At the seedling stage, irrigation should be controlled to promote root development and prevent excessive growth and lodging. During the flowering period, irrigate frequently and shallowly to promote uniform flowering, concentrated seed setting, and early maturity. In the later period, irrigation should be controlled to prevent delayed maturity due to excessive vegetative growth. Generally, the first watering is irrigated after bolting at the early flowering stage, the second watering at the full flowering stage, and the third watering at the grain-filling stage, to prevent water accumulation in the field. The whole growth period is irrigated 3--4 times.
9. Prevent and control pests. During the growth period, fennel is prone to aphid damage, which can be controlled by spraying 30--40 g of pirimicarb, fenvalerate, or deltamethrin diluted with 30--40 kg of water in the morning and evening.
10. Harvest at the right time. Fennel belongs to an indeterminate inflorescence, with a long flowering period, and the seeds mature unevenly, so harvest should be carried out in stages, that is, when the first-order branch inflorescence matures, cut and harvest once first, and after the second-order inflorescence matures, harvest fully, generally harvesting in late September. After harvesting, promptly transport to the drying yard, place in a ventilated place to dry in the shade, to prevent the seeds from discoloring due to rain and sun exposure. After the plants are thoroughly dry, thresh and winnow them clean in time and put them in storage for sale.