Glehnia Root Cultivation Techniques and Key Field Management Points
Glehnia root is the dried root of the umbellifer Glehnia littoralis, also known as Laiyang glehnia. It has the functions of nourishing yin and clearing the lungs, and resolving phlegm and stopping cough. It is mainly produced in Shandong; Hebei, Liaoning, Jiangsu, Zhejiang, Fujian and other provinces also produce it.
(1) Morphological characteristics
Perennial herb, about 30 cm tall. Main root slender, cylindrical. Stem erect, sparsely branched. Cauline leaves with long petioles, base slightly broad-sheathing, leaves 1-3 times ternately divided to deeply parted, leaf blades leathery; ovate, margins serrate, upper stem leaves undivided, sparsely covered with fine soft hairs on both surfaces. Compound umbels densely covered with grayish-brown tomentum, rays 10-20, unequal in length; no involucre, involucel bracts 8-12, lanceolate; umbellules with 15-20 florets, tomentose, flowers small, white, calyx teeth 5, narrowly triangular-lanceolate, sparsely covered with coarse hairs; petals 5, apex inflexed; stamens 5; pistil 1, ovary inferior, style base flattened-conical, stigma 2-lobed. Schizocarp spherical or elliptic, fruit ribs winged, covered with brown coarse hairs, surface yellowish-brown or yellow-brown, seed 1. Flowering period May-July, fruiting period June-August.
(2) Growth habits
Prefers a warm and humid climate, cold-resistant, drought-tolerant, dislikes waterlogging, and avoids continuous cropping and peanut stubble.
The seeds belong to the low-temperature dormancy type of post-embryonic ripening; generally the after-ripening process can only be completed after about 4 months at a soil temperature below 5°C, and only then can the seeds germinate normally. Seed longevity is one year.
(3) Cultivation techniques
1. Site selection and land preparation. Choose sandy loam with deep soil layers, loose and fertile texture, and convenient drainage and irrigation for planting; the previous crop is best wheat, millet, corn, etc. Clay soil and low-lying waterlogged land are not suitable for planting. Apply 6000 kg of farmyard manure per 1000 sq m as base fertilizer, plow 50 cm-60 cm deep, break up clods and rake level, then make beds 1.5 m wide, and open drainage ditches 50 cm deep around them.
2. Propagation method. Propagate by seed, preferably by autumn sowing. There are two sowing methods. Wide-row drilling: sowing width about 15 cm, open furrows 4 cm deep across the bed, the furrow bottom should be level, row spacing 25 cm, sow seeds evenly, seed spacing 4 cm-5 cm; the covering method is to cover the previous furrow with soil when opening the second furrow, and the covering soil thickness should preferably be 3 cm. Narrow-row drilling: sowing width 6 cm, row spacing about 15 cm, the rest the same as wide-row drilling. The sowing rate depends on soil texture; generally 6 kg-9 kg of seed per 1000 sq m. After sowing on pure sand land, it needs to be pressed with yellow mud or small broken stones to prevent strong winds from blowing away the seeds.
3. Field management. After the soil thaws in early spring, if the surface is compacted, loosen the soil with an iron rake to preserve moisture. Because glehnia is a densely planted crop with small row spacing, and the stems and leaves are tender and easily broken, hoeing for intertillage should not be used after emergence; weeds must be pulled at any time, and when the seedlings have 2-3 true leaves, thin them in a triangular arrangement at a plant spacing of about 3 cm. If flower buds appear on small glehnia seedlings, they should be removed promptly. Standing water during the rainy season should be drained promptly.
4. Pest and disease control
(1) Root-knot nematode disease: begins in May, damaging the roots. For control methods, see Salvia miltiorrhiza.
(2) Viral disease: begins in early to mid-May, damaging leaves and the whole plant. Control aphids and red spider mites; select disease-free plants for seed production.
(3) Rust disease: also called yellow jaundice, begins in mid to late July, damaging stems and leaves. For control methods, see Bupleurum.
(4) Stem borer: larvae bore into glehnia leaves, stems, roots, and flower buds to cause damage. Control methods: from July to August, on windless nights, use lights to trap and kill adults; during the egg stage and when the newly hatched larvae have not yet bored into the plants, spray with 90% trichlorfon 400-fold solution or 20% dimethoate 1000-fold solution.