Abstract

S6-24

True Cassava Seed Programme for Food Security in Developing Countries

Rajendran P.G. and C. Mohan

Cassava has enormous potential for poverty alleviation and food security due to its ability to grow and yield well in marginal and waste lands under minimal management.  The slow multiplication rate under clonal propagation, huge bulk of planting material, the quick spoilage of stems cuttings under storage and the perpetuation of ocassava mosaic disease (CMD) through infected cuttings are the major impediments against its cultuvation ,which limit its potential as a food crop of the rural poor in the developing countries.  The potential of true cassava seed (TCS) programme as a viable alternative to the conventional clonal propagation has been explored at the Central Tuber Crops Research Institute, Trivandrum between 1988 and 2002.  The following aspects were studied: germplasm evaluation; seed output and germination among male fertile, male sterile and inbred and hybrid progenies; seed viability and storage under diverse conditions; factors influencing seed germination and sprouting; optimising nursery technique for seedlings; conditions for seedling establishment in the field; stimulating clonal yield in the seedlings; CMD incidence among seedlings and clones; yield potential of seedlings and that of the first clonal progenies (C₁) of promising parents; dry matter, starch and HCN content of tuber at different stages among seedlings and the first clones in comparison to the parental clones; effect of growth regulators on seedling tuber yield and standardization of agro-techniques of seed crop.  It was observed that the multiplication rate increased fifteen folds.  CMD  was reduced since it was not transmitted through sexual seeds.  Extensive areas was brought under cultivation with 1.5 kg of sexual seeds per hectare.  True seeds were viable for about 8 months and any amount of seeds can be stored securely under ambient conditions.  Seed crop of promising parents under closer spacing produced comparable storage roots, dry matter,  starch and HCN content to that of the clones. Regional adaptive trials indicated that the programme can be successfully adopted in India.