Performance of selected sweetpotato varieties in Kenya

Abstract

The major constraints to sweetpotato production in Kenya are use of low yielding albeit well adapted varieties and poor agronomic practices. Utilisation of higher yielding varieties could therefore increase yields. This study was conducted to evaluate introduced germplasm and identify clones with desirable traits. Twenty five clones selected on the basis of high root yield and high dry matter content were evaluated during the 1998 and 1999 long rains seasons. From these, 12 clones were selected for further evaluation in the 2000 long rains. Significant (P = 0.01) genotypic effects were observed for all traits, while genotype x season interactions were significant (P = 0.05) for large and total root yields. Twenty two of the clones had significantly lower foliage yields, compared to the check variety Mafuta. Clones 282-H-12 and WAGA-L-4 consistently recorded dry matter content of over 30%, which is above the critical value of 27%. Mean total root yields were highest in 1999 (14.6 tons ha-1) followed by 1998 (12.0 tons ha-1). The best performing clones were TZ-H-7, 120-H-11, 282-H-12 and TZ-H-10, all producing over 20 tons ha-1 with TZ-H-7 yielding significantly higher than the check variety Naveto. TZ-H-7 also recorded the second highest yield of 13.3 tons ha-1 during 2000. The consistently high number of clones outyielding the check varieties suggests a gain from introduction of new germplasm into the breeding programme in Kenya.


Key Words: Dry matter, foliage production, germplasm, sweetpotato breeding


(African Crop Science Journal 2001 9(1): 49-58)