Cultivation of Medicinal Plants in India: A Complete Guide for cultivating some of the most profitable medicinal plants in India!
Medicinal Plant 1 # Cultivation of Babul:
Babul is characteristic of the dry regions, but does not thrive without irrigation if the climate is too arid. In regions where it is indigenous or has become naturalized, the absolute maximum shade temperature varies from 40 to 50° and the absolute minimum from — 1 to 15°, and the normal rainfall from 7.5 to 125cm. The tree is frost-tender, but is drought-resistant so long as the sub-soil moisture holds out, it is not fire-resistant.
Babul thrives best on riverain alluvium subject to inundation, and on black cotton soil. It is also found on alluvial loam in the plains of northern India, on loamy soil in the peninsula and in tank beds in Tamil Nadu. It survives even on usar (saline) soils.
The tree is seldom leafless. Leaf-shedding commences before May and continues up to the end of May; the new leaves appear during March-May. The trees generally flower during the rainy season, but flowering may extend to Dec-Jan; fruiting is usually from April to June. Trees commence to bear fruit at an early age, and seed annually. The pods are readily eaten by sheep, goats and cattle, and seeds are disseminated by them.
Under natural conditions germination commences early in the rainy season and continues for some time. For vigorous natural reproduction, complete sunlight, abundant moisture, loose soil and absence of grass and weed are essential.
Direct sowing, either in lines or on ridges, has proved successful for afforestation. Choice of a suitable site, treatment of the soil, preparation of seed, weeding and thinning at regular intervals are essential for obtaining good results. Within a year or two the new plants attain a height of 1.5-2.0 m. In afforestation studies carried out in different arid habitats of Rajasthan, babul was found suitable for shallow alluvial soils overlying hard calcareous pans within the 300-400 mm isohyet.
Medicinal Plant 2 # Cultivation of Aconitum Napellus:
The chief collecting centres for foreign Aconite root have been the Swiss Alps, Salzburg, North Tyrol and Vorarlberg. Much was also formerly collected in Germany. Supplies from Spain and Japan are imported, so that the demand for English Aconite is somewhat restricted.
The official Aconite is directed by the British Pharmacopoeia to be derived only from plants cultivated in England, and a certain amount of home-grown Aconite has been regularly produced by the principal drug-farms, though good crops are grown with some difficulty in England, and cultivation of Aconite has not paid very well in recent years.
Aconite prefers a soil slightly retentive of moisture, such as a moist loam, and flourishes best in shade. It would probably grow luxuriantly in a moist, open wood, and would yield returns with little further trouble than weeding, digging-up and drying.
In preparing beds for growing Aconite, the soil should be well dug and pulverized by early winter frosts – the digging in of rotten leaves or stable manure is advantageous.
It can be raised from seed, sown ½ inch deep in a cold frame in March, or in a warm position outside in April, but great care must be exercised that the right kind is obtained, as there are many varieties of Aconite — about twenty-four have been distinguished — and they have not all the same active medicinal properties. It takes two or three years to flower from seed.
Propagation is usually by division of roots in the autumn. The underground portion of the plants are dug up after the stem has died down, and the smaller of the ‘daughter’ roots that have developed at the side of the old roots are selected for replanting in December or January to form new stock, the young roots being planted about a foot apart each way. The young shoots appear above ground in February. Although the plants are perennial, each distinct root lasts only one year, the plant being continued by ‘daughter’ roots.
This official Aconite is also the species generally cultivated in gardens, though nearly all the species are worth growing as ornamental garden flowers, the best perhaps being A. Napellus, both white and blue, A. paniculatum, A. Japonicum and A. autumnale. All grow well in shade and under trees. Gerard grew four species in his garden: A. lyocotonun, A, variegatum, A. Napellus and A. Pyrenaicum.
Medicinal Plant 3 # Cultivation of Acorus Calamus:
The plant is grown in clayey loams and light alluvial soil of river banks. The field is irrigated and ploughed with green manure before planting. The growing ends or tops of the previous year’s crop are planted 30 cm apart, leaving the leafy portions well above the ground. The crop is ready for harvest in about a year.
The plants are dug out, rhizomes removed, and the tops kept for the next planting. The rhizomes are cut into pieces of 5-8 cm and all fibrous roots are removed. The pieces are washed thoroughly and dried in the sun. The dried material is put into rough gunny bags and rubbed to remove the leafy scales. The yield of rhizome is c 3,750 kg/ha and with proper cultivation, almost double the yield is possible.
The crop is free from pests and diseases, apart from stray attacks of a leaf spot, which does not seem to affect either the growth or the yield in any way. An aphid-transmitted mosaic streak disease of wheat is also reported.
The rhizome may have poisonous effect under certain conditions causing disturbed digestion and in severe cases, gastroenteritis.
Medicinal Plant 4 # Cultivation of Althaea Officinalis:
The herb has been successfully introduced into Manali at 2,000 m altitude, and cultivated in the gardens of Kulu valley in Himachal Pradesh. In South India, it is grown not only for ornament but also for the medicinal root. In Uttar Pradesh, it has been introduced through seeds obtained from USSR. The herb grows in loose garden soil of moderate fertility. Both seeds and rootstocks are employed for propagation. The seeds are sown 15cm apart in the nursery in March; they germinate in April.
The seedlings, when 5-8 cm in height, are transplanted to a spacing of 45 cm x 45 cm. If the rootstocks are employed, they are cut into pieces, each with a bud, and planted. The rootstocks can be collected along with the roots in October in the second year when the plant is 1.3—1.8 m tall. The roots are washed, cut into pieces, peeled and carefully dried under the sun or in heated sheds. The drug should be protected from insects.
The yield of the dry roots obtained at Manali was 386 kg/ ha. The physical properties of the soil appear to be important for the production of drug rich in mucilage. In sandy soils, the mucilage in the roots is reported to be higher than in clayey soils. The mucilage is maximum in autumn and winter and minimum in spring and summer; increase in soil-moisture reduces the mucilage.
Medicinal Plant 5 # Cultivation of Aristolochia Indica:
It can be propagated by seeds which germinate in about two weeks. Seeds can be collected by bagging the fruits. The seeds are sown in June in well-manured beds. Seedlings are transplanted after six weeks and trained on to bamboo platforms. The vines flower in September and fruit during February-March.
They are allowed to grow for two years to yield roots of marketable size. The yield of roots is estimated at 4500-5600 kg/ha from two year old vines. The roots are collected in the autumn. The adhering earth is removed by minimum washing. The roots are dried in the sun or by gentle heat.
Medicinal Plant 6 # Cultivation of C. Procera:
C. procera has been observed to grow mainly on coarse, sandy and alkaline soils. The growth is luxuriant on rubbish heaps, waste and fallow lands, roadsides, on the ruins of buildings, sea-shores, river banks etc. In C. procera, on sand-dunes, the root branching is more than in other soils. Both the species easily grow from seeds; even root and shoot-cuttings are recommended. They do not require specific cultivation practices or irrigation. They are good soil-binders, and are recommended for deserts.
They have a lifespan of c 12 years. The plants flower during Dec.-July and fruit during Feb.-June; in some regions such as in the cotton belt of Vidarbha and in many parts of South India, they flower and fruit throughout the year. When found as a weed of cultivation, milkweed is very difficult to eradicate. It can be eradicated either by physically rooting out the whole plant or through application of chemicals. The former method does not give 100% success as the roots go very deep and cannot be removed fully, and may sprout again.
Weedicide trials with esters of 2, 4-D and 2, 4, 5-T in the proportion of 2:1 were undertaken in three ways- (1) by hypodermal injection; (2) cutting the plants and spraying the new shoots; and (3) spraying the plants when they were in full bloom. The last method was found to be best suited for the practical control of this weed.
A few fungi Cercospora calotropidis Ell. & Ev., Mycosphaerella calotropidis Visw. and Curvularia pal-lescens Boedijn are reported to parasitize the leaf of C. gigantea. Dendrophthae falcata (Linn, f.) Ettingsh. an angiospermic parasite, is also recorded on the plant. Amsacta moorei Butler and Aphis nerii Boyer feed on the plant.
Medicinal Plant 7 # Cultivation of Carum Carui:
Caraway requires arid summer with a rainfall of 15-20 cm and extremely cold winters for its proper growth. Heavy snowfall in winter (3-5 m) helps in the initiation of the floral primordia while low rainfall in summer ensures good flowering and fruiting as well as flavour and quality of seed produced. Although it can be grown successfully in any kind of soil, loams and sandy loams free from water-logging are best for proper development of “bulbs” (storage roots).
The land is ploughed or dug up twice or thrice. The crop requires large quantities of organic matter in the form of humus. Upto 25 tonnes of farmyard manure per hectare is mixed in the soil before sowing.
The plants can be raised from healthy seeds or from bulbs. The optimum time of seed sowing or transplanting of bulbs is mid- October to mid-November in the hills. The seeds are sown in lines 20-30 cm apart; 5.0-7.5 kg of seeds are required for a hectare. The seeds germinate in March-April and develop small bulbs in the first year and remain dormant till the following February. Later, when the plants are 5-7 cm in height, they are thinned to keep 20 cm distance in the line.
The aerial growth dries up during winter. This cycle is repeated for four growing seasons after which flowering and fruiting takes place. Thereafter, the plants flower and fruit in May-June every year and yield for about ten years. The plants can also be raised from bulbs, but for this, the seeds are sown in nursery and allowed to form bulbs in three years. Then the bulbs are transplanted in October in lines 30 cm apart keeping a distance of 20 cm between plants in the same line.
The bulbs sprout in March- April and bear flowers and fruits in June. Bigger-sized bulbs tend to give higher yields of seed. Heavy mulching with farmyard manure or compost is also beneficial. The bulbs once planted continue to flower and fruit for the succeeding ten years.
The fields are kept clean during the growing period by shallow hoeings. The crop is irrigated once a fortnight during dry period. When the seedlings are 5-7 cm in height, they are thinned to a distance of 20 cm in lines. Mulching with farmyard manure in Nov.-Dec. encourages early and better sprouting. Application of 30 kg nitrogen and 12 kg of phosphorus per hectare as top dressing is beneficial.
Caraway is subject to attack by the mustard aphid during flowering and fruiting. Occasionally, the cabbage butterfly and caterpillar infest the umbels. White grub is a serious pest affecting the bulbs. Application of Aldrin or Folidol dust (8-10 kg/ha) at the time of hoeing and weeding is recommended to control these pests. The plants are also infected by Alternaria and Cladosporium species. Two or three sprays of copper oxychloride control these fungi.
Medicinal Plant 8 # Cultivation of Cephaelis Ipecacuanha:
The plant is unusually slow-growing and cultivation outside Brazil has not been uniformly successful. It has been grown on a commercial scale only in Malaysia and to a small extent in Myanmar and India. In India, it is cultivated in Mungpoo (Darjeeling) and Nilgiris, especially near Kallar, as a subsidiary crop. At the Rungbee Cinchona plantation in Sikkim c 60,000 plants have been raised.
The plant is also cultivated at Jorhat in Assam, and Khasi and Jaintia hills in Meghalaya. At Rongo and Mungpoo in Darjeeling c 19,000 kg root was produced during 1966-67. During 1982, about 80 ha were under Ipecac cultivation at Mungpoo. The trials at Nilambur in Kerala also gave encouraging response. In West Bengal, the plant generally survives for 5-6 years. The drug was earlier imported into India.
The plant thrives best in forests, as it requires well-drained, acidic and sandy loams, rich in humus, calcium phosphate, potash, magnesia and lime. Considerable increase in the yield has been reported in West Bengal, when ammonium sulphate was used in soil containing humus; the oil cake at the rate of 200 g/bed of 2.7 m x 1.2 m size is also reported to enhance the yield of roots. Highest root yield of 1.95 kg was obtained in medium containing oil cake 200 g and leaf mulch 100 kg/bed of 3.25 m2.
When leaf mulch alone was used, yield of root was 1.4 kg. Maximum yield of alkaloids is reported when 100 g superphosphate per bed was applied, whereas, superphosphate in combination with nitrogenous fertilizers increases the formation of non-phenolic alkaloids. Treating the roots with boron and IBA increased the number of annulated roots. Polyploidy is also reported to increase the alkaloidal contents.
For successful cultivation, a temperature of 10- 38° with a very narrow fluctuation and a minimum well-distributed rainfall of 225-500 cm per year and shaded situations are essential. A permeable split-bamboo shed can also be used which permits rain and also protects the seedlings from intense sunshine. The soil is also protected with black polythene sheets and bigger seedlings are planted through holes made in the sheets.
Before the development of leaf-canopy, plugging the holes in polythene sheets with mosses can prevent the exposure and uprooting of seedlings. It is reported that under these conditions, the seedlings grew up fairly well at Meghalaya and the survival rate was quite high, but the leaves turned slightly yellow. Attempts at growing two-year-old plants in the open by removing the thatch from the sheds during the rains resulted in the leaves turning white. The green colour was restored when the beds were thatched over again.
The plants can be raised from seed, leaf or stem or root- cuttings. The survival of the sprouts from stems is 40-50% as compared with the transplanted seedlings. The root-cuttings are, however, more vigorous and healthy. The seeds take 3-5 months, sometimes even 6 months, to germinate. The cuttings are planted 30 cm apart, preferably on raised beds for good drainage.
In Darjeeling, when seeds are employed, they should be sown at 15-day interval from June to March at the rate of 120 g (c 7,000 seeds) per 3.25 m2 under nursery shade. As the stored seeds lose their viability, fresh seed should be used. The seeds are sown at a spacing of 15 cm x 15 cm, and sometimes they are broadcast. After sowing, the seeds should be covered with pure sand up to 1 cm. The propagation from matured leaves was found to be possible but the development of root was poor. The seed-raised plants are slow in growth.
Inspite of the fact that the plant is grown in heavy-rainfall areas, the seed-beds need almost daily watering. If the soil dries up and crust is formed, the soil is worked to break the crust and the beds are left dry for aeration. After three days, watering is continued. The process is repeated throughout the year. Weeding and hoeing also are essential until the seedlings establish.
Ideal germination is obtained in mid-Jan to mid-Feb. sowings, with 40-45% germination rate. Germination can be further improved by treating the seeds with lime-water for 48 hrs and with hydrogen peroxide for 96 hrs. In Meghalaya, the seeds are sown from February till mid-July, February sowing giving upto 59% germination.
When the seedlings are 2 months old, they should be transplanted at a spacing of 10 cm x 10 cm in 3.25 m2 beds. Transplanting during June-July is reported to be the best and more than 95% of the seedlings survive. Later transplanting results in lesser survival. In West Bengal, a bed of 2.7 m x 1 .2 m, and in Meghalaya a bed of 15 m x 1.5 m proved to be the optimum for better survival, and higher yield of dry roots and total alkaloids.
Production of roots per bed was also maximum during June and July transplanting, and about 0.9-1.0 kg of dry roots per bed could be obtained. In West Bengal, the use of black polythene sheets over growing seedlings increased the formation of roots and total alkaloids in two-year-old plants by 24.0-33.4 per cent. The plant starts flowering from the second year and fruits ripen 3 months later or so.
A wilt caused by Fusarium solani (Mart.) Appel. & Wollenw. var minus Wollenw. was reported on the leaves from Assam, causing yellowing, wilting, drying and leaf-fall, and drying of stems. At the first stage, the roots are not so markedly affected but after the death of the upper portion, the infection extends through vascular bundles. A leaf blight caused by Alternaria alternata (Fr.) Keissler has been reported on the plant.
The maximum production of root is in between third and fourth year, and a healthy plant yields 6-8 roots of good quality.
The root- stem portion contains maximum quantity of both total and non- phenolic alkaloids. The production of fruits and seeds increases with age upto third year and thereafter decreases, but the production of roots increases and reaches maximum after fourth year. The formation of alkaloids in fruits and roots also increases with the age of plants and the maximum is reported in the third and fourth year.
Medicinal Plant 9 # Cultivation of Chenopodium Album:
The seed is broadcast during April at higher elevations and in June-August at lower elevations. If wide- spaced, the plants grow vigorously. The crop matures in 135-146 days. The plants are harvested, dried, threshed and the grain is winnowed. The yield varies greatly. The growth of this plant is highly stimulated by magnesium and may be an indicator for this element.
As a weed, its infestation of wheat is severe. It can be controlled through clean cultivation. When the main crop is young, weedicides give promising results in controlling the weed. At the seedling stage, application of Diuron proved useful to control this weed in orchards. The species produces aeroallergens.
Medicinal Plant 10 # Cultivation of Thorn-Apple:
Thorn-apple is easily cultivated, growing well in an open, sunny situation. It will flourish in most moderately good soils, but will do best in a rich calcareous soil, or in a good sandy loam, with leaf mould added.
Seeds are sown in the open in May, in drills 3 feet apart, barely covered. Sow thinly, as the plants attain a good size and grow freely from seed. Thin out the young plants to a distance of 12 to 15 inches between each plant in the drill. From 10 to 15 lb. of seed to the acre should be allowed.
The soil should be kept free from weeds in the early stages, but the plants are so umbrageous and strong that they need little care later. If the summer is hot and dry, give a mulching of rotted cow-manure.
The plants may also be raised from seeds, sown in a hot-bed in February or March, or in April in boxes in a cool greenhouse, the seedlings, when large enough, being transferred to small pots, in which they are grown with as much light and air as possible till June, when they are planted in the open. Thorn-apple transplants readily.
If grown for leaf crop, the capsules should be picked off as soon as it formed, as in a wind the spines tear the leaves. Some seed for propagation purposes should always be collected from plants kept specially for the purpose.
Though cultivated in this country, on some of the herb farms, such as Long Melford and Brentford, Thorn-apple was not much grown on a commercial scale before the War, considerable quantities of the dried leaves having always been imported from Germany and Hungary.
Medicinal Plant 11 # Cultivation of Foeniculum Vulgare Mill:
Fennel will thrive anywhere, and a plantation will last for years. It is easily propagated by seeds, sown early in April in ordinary soil. It likes plenty of sun and is adapted to dry and sunny situations, not needing heavily manured ground, though it will yield more on rich stiff soil. From 4½ to 5 lb. of seed are sown per acre, either in drills, 15 inches apart, lightly, just covered with soil, and the plants afterwards thinned to a similar distance, or sewn thinly in a bed and transplanted when large enough. The fruit is heavy and a crop of 15 cwt. per acre is an average yield.
The roots of Fennel were formerly employed in medicine, but are generally inferior in virtues to the fruit, which is now the only portion recognized by any of the Pharmacopaeias.
The cessation of the supply of Fennel fruits from the Continent during the War led to its being grown more extensively here, any crop produced being almost certain to sell well.
There are several varieties of Fennel fruit known in commerce- sweet or Roman Fennel, German or Saxon Fennel, wild or bitter Fennel, Galician Russian and Romanian Fennel, Indian, Persian and Japanese. The fruits vary very much in length, breadth, taste and other characters, and are of very different commercial value.
The most esteemed Fennel fruit vary from three to five lines in length, are elliptical, slightly curved, somewhat obtuse at the ends and pale greyish green in colour. Wild fruits are short, dark coloured and blunt at their ends, and have a less agreeable flavour and odour than those of sweet Fennel—they are not official.
Fennel fruits are frequently distinguished into ‘shorts’ and ‘longs’ in commerce, the latter being the most valued.
The odour of Fennel seed is fragrant, taste, warm, sweet and agreeably aromatic. It yields its virtues to hot water, but more freely to alcohol. The essential oil may be separated by distillation with water.
For medicinal use, the fruits of the cultivated Fennel, especially those grown in Saxony, are alone official, as they yield the most volatile oil. Saxon fruits are greenish to yellowish-brown in colour, oblong, smaller and straighter than the French or Sweet Fennel (F. dulce).
This French Fennel, known also as Roman Fennel, is distinguished by its greater length, more oblong form, yellowish- green colour and sweet taste; its anise-like odour is also stronger. It is cultivated in the neighbourhood of Nimes, in the south of France, but yields comparatively little oil, which has no value medicinally.
Indian Fennel is brownish, usually smaller, straighter and not quite so rounded at the end with a sweet anise taste. Persian and Japanese fennel, pale greenish brown in colour, are the smallest and have a sweeter, still more strongly anise taste and an odour intermediate between that of French and Saxon.
The Saxon, Galician, Romanian and Russian varieties all yield 4 to 5 per cent, of volatile oil, and these varieties are alone suitable for pharmaceutical use. In the ordinary way they furnish some of the best Fennel crops, and from their fruit a large portion of the oil of commerce is derived.
For family use, ½ oz. of seed will produce an ample supply of plants and for several years, either from the established roots, or by re-seeding. Unless seed is needed for household or sowing purposes, the flower stems should be cut as soon as they appear.
Medicinal Plant 12 # Cultivation of Hibiscus Esculentus:
Numerous types, indigenous and imported, are under cultivation. They are distinguished by their growth habit, length of pods, colour of stem and pods, nature of pod surface and number of ridges (ribs) on pods. There are tall and dwarf forms with long or short pods maturing early or late; the pods may bear five or eight ridges.
Some of the best imported types are Clemson, Spineless, American Long Green and White Velvet; they are mostly free from spiny hairs and bear pods with faint ribs. Several local strains with smooth pods are also known. A new type, Pusa Makhmali, isolated by the Indian Agricultural Research Institute bears green pods 6-8 in. long, straight, five-ribbed and smooth.
Two crops are usually raised in a year, one sown in the beginning of summer (February-March) and harvested in July- August; and the second sown with the onset of rains in June and harvested in October-December. For the summer crop, early maturing types with five-ribbed, smooth pods are preferred, while for the rainy season crop, late maturing types with eight-ribbed, smooth or hairy pods are grown. A number of types suitable for growing in both seasons are available; Pusa Makhmali is an outstanding example.
The land is ploughed 3-4 times and farmyard manure applied at the rate of 20-25 cart loads per acre. Seeds are sown broadcast or are dibbled in holes, 2 or 3 seeds per hole. They may be drilled also in shallow furrows, 9 in. apart, with a spacing of 3 in. between plants in the furrow. In some places, seedlings are raised in nurseries and transplanted in the garden. The seed rate ranges from 5-30 lb. per acre.
To get a continuous supply of fruits, it is usual to sow the seeds in batches, in different beds, at intervals of 2-3 weeks during the sowing season. The plant responds well to proper inter-culture and weeding. In the case of the summer crop, it may be necessary to irrigate the plants once in 7 or 10 days.
Yield:
The fruits of the summer crop are ready to be picked 40-50 days after sowing; fruiting in monsoon crops takes a little longer, 60-70 days from sowing. The fruiting period in summer extends over 2 months; the period is much longer in the rainy season crop and extends up to the winter season. The fruits become tough after gathering and should therefore be disposed off as soon as possible.
The average yield of green pods per acre is reported to be 4,000-5,000 lb.; higher yields are obtained under favourable conditions. Pusa Makhmali is reported to have given a yield of 16,400-20,500 lb. of pods per acre.
Medicinal Plant 13 # Cultivation of Hyoscyamus Niger:
Common henbane is a diploid with 2n=34 (6). Very little work has been done on breeding of common henbane. Recently, mutants have been produced with higher alkaloid content (12, 13). Artificial tetraploids have also been produced which contain higher amount of alkaloid.
Henbane grows well in light loam fertile soils of light texture. It is a temperate plant and it can also be cultivated in sub-tropical areas. In India, sub-tropical north Indian plains are suitable for cultivation of the crop. However, the alkaloid content is much better, if cultivated in temperate areas like Kashmir valley.
Common henbane is propagated through seeds. Seeds can be sown directly in the field or a nursery can be raised and seedlings transplanted in the field. It is always better to raise a nursery in order to get a good crop stand. Nursery is raised during spring months of March-April in temperate areas and during September- October in sub-tropical areas like north Indian plains. Planting time has been found to be an important factor in Italy.
Nursery should be raised in raised beds containing soil and well-rotten farmyard manure. Seeds should be sprinkled on the surface and covered with a thin layer of sand and compost. Beds should be kept wet by regular watering. 500 G seeds are sufficient for planting in one hectare.
Seeds germinate in 10-15 days and the seedlings are ready for transplanting in 4-6 weeks after germination. Six-week old seedlings should be planted in the field at a distance of 15 cm from plant to plant in rows which are 45 cm apart during November-December in subtropical areas and during May-June in temperate areas. The field should be irrigated immediately after transplanting.
In case of direct sowing seeds are drilled directly in shallow furrows (1.25 cm deep) in moist soil at a distance of 45 cm and these are thinned to the desired distance after the seedlings are 4- 6 weeks old.
Inter-Culture and Weed Control:
The crop should be kept free from weeds by repeated weedings and hoeings. Experiments in India have shown that 2-3 hoeings and weedings are necessary to get a good crop (5, 7).
Henbane responds well to fertilizer application. It is advisable to apply 30 kg P2O5, 30 kg K2O and 20 kg N per hectare as a basal dose at the time of planting. Nitrogen at the rate of 40 kg per hectare in two split doses is applied during the growing season, specially when the plants are young (5, 7). Experiments have shown that nitrogen, potash and phosphorus increase both yield as well as alkaloid content in common henbane. It has also been observed that applying nitrogen in the early stages is more beneficial as compared to late top dressing.
The crop should be irrigated 3-4 times in areas where there are no rains. However, waterlogging should be avoided.
Henbane is used to a limited extent as tincture wards. The flowers have a hairy, pitcher-shaped calyx, which remains round the fruit and is strongly veined, with five stiff, broad, almost prickly lobes. The corollas are obliquely funnel-shaped, upwards of an inch across, of a dingy yellow or buff, marked with a close network of lurid purple veins. A variety sometimes occurs in which the corolla is not marked with these purple veins.
The seed-capsule opens transversely by a convex lid and contains numerous small seeds. Perhaps, the most striking feature of the plant are these curious seed-vessels, a very detailed description of which is given in the works of Flavius Josephus, as it was upon this capsule that one of the ornaments of the Jewish High Priests’ head-dress was modelled. The whole plant has a powerful, oppressive, nauseous odour.
Henbane is in such demand for medicinal purposes that it is necessary to cultivate it, the wild plants not yielding a sufficient supply. Both varieties were formerly cultivated in England, but at present the biennial is almost solely grown. English-grown Henbane has always been nearly sufficient to provide enough fresh leaves for the preparation of the juice, or green extract, but large quantities, chiefly of the annual kind, were imported before the War from Germany, Austria and Russia, in the form of dry leaves.
Henbane will grow on most soils, in sandy spots near the sea, on chalky slopes, and in cultivation flourishing in a good loam.
It is, however, very capricious in its growth, the seeds being prone to lie dormant for a season or more, refusing to germinate at all in some places, and the crop varying without any apparent reason, sometimes dying in patches. In some maritime localities it can be grown without any trouble.
It requires a light, moderately rich and well-drained soil for successful growth and an open, sunny situation, but does not want much attention beyond keeping the ground free from weeds.
The seed should be sown in the open, early in May or as soon as the ground is warm, as thinly as possible, in rows 2 to 2½ feet apart, the seedlings thinned out to 2 feet apart in the rows, as they do not stand transplanting well. Only the larger seedlings should be reserved, especially those of a bluish tint.
The soil where the crop is to be, must have been well manured, and must be kept moist until the seeds have germinated, and also during May and June of the first year. It is also recommended to sow seeds of biennial Henbane at their natural ripening lime, August, in porous soil.
The ground must never be water-logged, especially in the first winter; it runs to stalk in a wet season. Drought and late frosts stunt the growth and cause it to blossom too early, and if the climatic conditions are unsuitable, especially in a dry spring and summer, the biennial Henbane will flower in its first year, while the growth is quite low, but well-manured soil may prevent this.
Care must be taken in selecting the seed- commercial Henbane seed is often kiln-dried and useless for sowing. In order to more readily ensure germination, it is advisable to soak the seeds in water for twenty-four hours before planting- the unfertile seeds will then float on the top of the water and may thus be distinguished.
Ripe seed should be grey, and yellowish or brown seeds should be rejected, as they are immature. Let the seeds dry and then sift out the smallest, keeping only the larger seeds.
Henbane seed being very small and light should be well mixed with fine dry soil as it is sown.
As seedlings often die off, a reserve should be kept in a box or bed to fill gaps, even though they do not always transplant successfully.
If it is desired to raise a crop of the annual variety, the plants, being smaller and not branching so freely, may be grown at a distance of 18 inches apart each way, but the annual is very little cultivated in this country.
If any annuals come up among the biennials sown, the flowers should be cut off until the leaves get larger and the stem branches.
There is usually some difficulty in growing Henbane owing to its destruction by insects- sometimes the whole of the foliage is destroyed by the larvae of a leaf-mining fly, Pegomyia Hyoscyami, and the crop is rendered worthless in a week. And when the large autumnal leaves of the first-year plants of the biennial variety decay, the large terminal bud is often destroyed by one of the various species of macro-lepidopterous caterpillars which hide themselves in the ground.
The crown or bud should be covered as soon as the leaves have rotted away with soil mixed with soot or naphthaline, to prevent the depredations of these and other insects.
Floods may also rot the plants in winter, if grown on level ground. Potato pests are fond of the prickly leaves and will leave a potato patch to feed on the Henbane plant.
If mildew develops on the foliage in summer, dust the plants with powdered sulphur or spray with ½ oz. of liver of sulphur in 2 gallons of water.
When it is desired to preserve seed for propagation, it is well to cut off the top flowering shoots at an early stage of flowering (these may be dried and sold as flowering tops), and allow only about six seed-capsules to ripen. This will ensure strong seed to the capsules left, and this seed will probably produce biennial Henbane, weaker seeds being apt to produce the less robust and less valuable annual Henbane.
Seeds sown as soon as ripe in August may germinate in autumn, and thus, constitute a biennial by growing on all through the winter and flowering the next summer.
Although the cultivation of Henbane in sandy ground near the sea, especially on the rich soil of estuaries, would probably pay well, it is hardly a profitable plant to grow in small gardens, more especially as the yield of dried leaf is very small. It is estimated that about-15 cwt. of dry herb are obtained from an acre of ground.
Medicinal Plant 14 # Cultivation of Indigofera Tinctoria:
For preparing indigo the plants are cut down in June and July, just before the process of flowering, placed in troughs, and after being pressed closely together they are covered with water. Fermentation then takes place and is allowed to continue from twelve to fifteen hours, when the body of the liquid acquires a sherry colour, and the surface becomes covered with a blue 111m.
It is then decanted, and the colouring principle dissolved by the water, absorbing oxygen from the air, becomes insoluble, and is gradually precipitated as a deep blue granular powder. This precipitation is facilitated by brisk agitation of the liquid, or by the addition of lime-water, or an alkaline solution.
The supernatant liquor is then drawn off, and the sedimentary matter after being heated is thrown upon a calico filter, where it is washed, and the indigo afterwards removed from the filter, pressed and cut usually into cubical cakes, and lastly dried, and sent into the markets.
The indigo thus obtained does not exist readily formed in the plant, but is generated in the process adopted for its preparation by a kind of fermentation from a principle, which, has been called by Schunck, its discoverer, indican.