Introduction

Perennial shrub Sarpagandha (Rauvolfia serpentina) is known as serpentine root or serpentina root is one of the most important crude drugs which has been used in the indigenous system of medicine from ancient times. The importance of this root drug and the alkaloids obtained from it has been recognized in allopathic system in the treatment of hypertension or as a sedative and tranqualising agent. A large number of alkaloids have been isolated from the roots of this plant such as ajmalicine, ajmaline, ajmalinine, rescinamine, reserpine, serpentine, serpentinine etc.

Requirement

• Climate

Sarpagandha grows in a wide range of climatic conditions. However, hot and humid tropical regions with sufficient rainfall are the most suited places. A range of temperature 10-30^o C is found favourable for the plants.

• Soil

The plant grows in a variety of soils ranging from sandy alluvial loam to red lateritic loam having acidic to neutral reaction.

Propagation

• Seed

The ripe seeds collected from the beginning of June to the end of October retain their viability for six months. Seeds are sown in raised beds at a depth of 1cm in the nursery in lines 10cm apart with 5cm distance from seed to seed. About 5.5kg of seeds sown in 0.05 ha area of nursery give adequate number of seedlings to plant one hectare. The seeds germinate within three weeks.

• Root cuttings

The large tap roots as well as lateral secondary rootlets are employed for preparing the cuttings of 2.5-3.0cm. Planting is done in holes of 5cm deep at the advent of monsoon and covered with 2.5-5.0cm top layer of soil. The cuttings sprout within three weeks if good moisture is maintained during the period.

• Stem cuttings

Stem cuttings of 15-20cm length with three internodes should be planted in the month of July-August in the nursery and kept moist. They strike roots within 60 days afterwards they are transplanted to the mainfield.

Planting

June and July are suitable months for transplanting seedlings and vegetatively propagated plants. The seedlings, which are 7.5-12.0cm high, are carefully dug out from nursery beds and planted. Regular irrigation, weeding and manuring are required for optimum growth.

Fertilizer

Organic manure is recommended @ 25-30 tonnes per hectare. A basal dose of 20kg nitrogen (N), 30kg phosphorus (P₂O₅) and 30kg-potash (K₂O) is applied per hectare and two top dressing of 20kg may be applied annually during the growing season.

Irrigation

Irrigation should be given at regular intervals. The crop may be irrigated fortnightly during hot dry season and once a month during winter.

Plant protection

Pest

Caterpillar

Caterpillars roll the leaves and feed on tender leave and causes defoliation.

• Control

Spray endrin 0.03%,

Disease

Die back

• Control

2-3 spraying with Dithane Z.78 (0.2%).

Leaf spot/leaf blight/powdery mildew

• Control

2-3 spraying with 0.5% Bordeaux

Harvesting and yield

The ideal age for the harvesting of the roots is after two or three years from the planting. In addition to the thick tap root, fibrous secondary roots should also be collected as they are rich in the alkaloid content. Digging forks are required to dig out the roots. Irrigation before the digging, will facilitate easy picking of main as well as secondary roots. The root-bark should not be damaged during harvesting. About 2000 kg of dried roots can be obtained from one hectare. The average total alkaloid yield is 2.4% in the root-bark as compared to 0.40% in the root wood.

• Drying

The harvested roots are thoroughly dried before storage. After air-drying, the roots are artificially dried so as to reduce the moisture content to about 3%. The dried roots are broken into small pieces of 15-20cm and packed in airtight containers for storage in a cool, dry place. Roots stored in godown may be periodically exposed to the air.