Senna variety ideal for rainfed farming in southern districts

SENNA (CASSIA angustifolla) is a medicinal plant variety grown predominantly in Tamil Nadu and Gujarat.

The pods and leaves of the plants are used in confectionery and herbal preparations.

It is also popular in western countries for making `herbal tea.' Nearly 75 per cent of senna produced in India is exported to western countries.

Senna is known as Sonamukhi in Hindi, Nilavaka in Malayalam, Nilavagai in Tamil, Nelaponna in Telugu and Nelavare in Kannada.

Senna crop can be grown both as a rain fed and an irrigated crop. In Tamil Nadu it is grown in the rain fed tracts of Tirunelveli, Ramanathapuram and Madurai districts.

Researchers at the Tamil Nadu Agricultural University (TNAU), Coimbatore have released a high yielding senna variety called KKM- 1which is suited for growing in Tirunelveli and Tuticorin districts of Tamil Nadu and is ideal for rain fed cultivation.

"The variety records a leaf yield of about 920 kg per hectare and pod yield of about 350 kg per hectare.

About 5 kg of seeds are required for sowing under irrigated conditions and about 12 kg of seeds are required for sowing under rain fed conditions," said Prof. K. Rajamani, Professor & Head, Medicinal Plants Unit, Horticultural College and Research Institute, Tamil Nadu Agricultural University (TNAU), Coimbatore.

The ideal time for sowing is during the month of February. Before sowing, a fertilizer dose of about 250 kg of super phosphate and 70 kg of potash must be applied in the field and ploughed well. About 175 kg of urea must be applied in three split doses on the 45th, 90th and 135th day after sowing.

For irrigated crops, the field should be ploughed into furrows and the seeds must be planted at 45x35 cm on the furrows.

For growing under rain fed conditions the seeds must be sown by broadcasting, according to Prof. Rajamani.

The field must be irrigated immediately after sowing and irrigation continued once every week. The seeds germinate in a week's time. The crop comes to harvest in about four months after sowing. Harvesting is done manually by plucking the matured leaves.

The leaves are graded according to their size and colour. Large and bold leaves and pods having a yellowish green colour are placed in first grade. Brown coloured leaves and smaller pods are placed in the second grade.

There is a general practice of drying the harvested leaves by spreading them on the floor, which results in contamination and affects quality. If the leaves are spread thickly and dried, it results in improper drying.

The appearance and leaf quality deteriorate due to the heat developed inside the thick layer, explained Prof. Rajamani. Improper and delayed drying changes the leaf colour to black, which results in a lower price in the market.

Farmers have to take care to store the harvested produce in a cool and dry environment. The quality of the harvested leaves and pods deteriorates due to high temperature, humidity and poor ventilation in the go downs.

For more information readers can contact Dr. K. Rajamani, Professor & Head, Medicinal plants unit, Horticultural College and Research Institute, Tamil Nadu Agricultural University (TNAU), Coimbatore, Phone: 0422-5511284, email:herbs@tnau.ac.in

Source: The Hindu