Introduction

In Tamil Nadu, Cassava or Tapiocais one of the most important tuber crops, grown in an area of 2.4 lakh ha with the annual production of 6.7 million tonnes. Tapioca is mainly utilized  for starch grain (sago) production and the raw tubers are processed into sago. Large and small scale starch industries are located in Salem, Erode, Namakkal, Dharmapuri and Krishnagiri districts.

Globally Maize is major contributor to starch and United State is the major player. However, recently United State has diversified the Maize for production of Biofuels, which has resulted in a shortfall of starch meant for food, which in turn increased the dependence on Cassava. Normally Cassava produces around 10-12 tonnes of starch from one hectare and it is the only crop which yields maximum starch per unit area.

Project Rationale

It has been estimated that the yield loss through Sri Lankan Cassava Mosaic Virus (SLCMV) disease, is around 40-60 percent (Calvert and Through, 2002) and also resulted in creditable loss in starch which accounted for 20-30 percent. Cassava Mosaic Virus disease is mainly transmitted through infected setts. Use of disease-free planting material is the best method to prevent the spread of the viral disease. In recent years, tissue culture technique is used for the production of disease-free planting materials.

Achievements in phase I (from Jan 2010 to March 2011)

The details of achievement in phase I of the project are furnished below.

• 300 plants (3 months old virus indexed H226 available in insect proof net house at orchard (In August, 2011 – 900 cuttings will be planted in field)
• Meristems isolated, cultured and              : 730

available for sub culturing

• I subcultured (No.of meristems)                : 490 (21 days old)
• II subcultured (No. of meristems)              : 360 (43 days old)
• III subcultured (No. of meristems)              : 343 (65 days old)
• IV subcultured (No. of plants)                     : 720 (88 days old)
• Primary hardening (No.of plants)              :160(118 days old)
• Secondary hardening (No. of plants)       :100 (150 days old)
• Rooting stage (No. of plants)                     : 50 plants  (180 days)

Project Strategy

In phase II, meristems will be isolated, cultured and in vitro plants hardened and indexed for virus. These will be mass multiplied under protected conditions and will be supplied free of cost to the farmers.

Project components

Virus elimination will be carried out by isolating the meristems from shoot tips which are free of viruses, further cultured and multiplied under in vitro and in vivo conditions. The same virus free materials will be supplied free of cost to the farmers.

Target

To cover an area of 1200 ha during 2011-2012 with virus free planting materials.

Contact:

Director,
Centre for Plant Protection Studies
Tamil Nadu Agricultural University
Coimbatore – 641 003
Phone: 0422-6611237 0422-6611437
Fax: 0422-6611437
E-mail: directorcpps@tnau.ac.in