| Foxglove |
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Requirement |
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The foxglove Digitalis includes several species. Digitalis purpurea and Digitalis Ianata are the two species recognized medicinally important as they contain three lanatoside A,B,C, which on hydrolysis yield digitoxin, gitoxin and digoxin, of which digoxin is the most important. The main use of these is in heart diseases and these glycosides have so far not been synthesised and hence cultivation of this crop is the only source of production of these glycosides. In D.purpurea glycoside content is 0.2-0.4% and in D.lanata (1-1.4%). |
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Requirement |
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It prefers a temperature range of 20 o- 30o C for better growth and development. At lower temperature, vegetative growth of the plants as well as the glycoside synthesis is retarded. The best elevation is 1200-1800m above mean sea level. |
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It requires a well drained sandy soil rich in organic matter. Soils with poor drainage is detrimental. pH range of soil is 5.5-6.5. |
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It can be raised from direct seeding or by raising in a nursery and then transplanting them to the main field. The land should be thoroughly ploughed, levelled and weeded for direct seeding. The seeds may be broadcast or sown in lines. About 8kg of seeds are required for sowing one hectare. Deep sowing should be avoided. |
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The nursery beds are raised in well prepared places and the beds are sown in lines at 10cm intervals and lightly covered with about 1cm of fine sand. The seedlings will be ready for transplanting 40-45 days after sowing. Spacing recommended is 45cm between rows and 30cm between plants in row. |
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Digitalis may be applied with 25-30 tonnes of farmyard manure per hectare. Besides, 30kg nitrogen (N) and 8kg phosphorus (P2O5) may be applied every year. in the first year the first dose may be given 2 months after germination or during February-March in the second year. It also responds to foliar nutrition in the form of urea (1.0%). |
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Leaves are the economic parts. 2-3 harvests of leaves can be made in the first year while in the second year 2 harvests besides a seed crop can be had. It is recommended to keep the plantations as annuals with 2-3 harvests in the first year and in the second year, some portion of the first year crop should be earmarked for seed production and from this crop, leaves have to be harvested just before flowering. Harvesting consists of plucking 8-10cm long leaves without petioles. |
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Drying the leaves before storage at proper temperature is another important factor. It is generally recommended to dry the harvested leaves by passing hot winds at 60 o C with occasional stirring. The dried leaves should be stored in airtight containers with dehydrating substance like silica gel. On an average 2-5.5 tonnes of dried leaves can be obtained from one hectare. |