Agronomic performance and carotenoid content of Kenyan yellow-fleshed cassava clones

Vitamin A deficiency is common in Kenya, and is common among populations that depend on cassava as their main staple. Clonal evaluation of 324 locally developed yellow-fleshed cassava clones was carried out in two sites, Thika and Kiboko located in central and eastern Kenya, respectively. Data were collected on agronomic performance, yield quality and reaction to biotic constraints. The clones rated well for the evaluated traits. The overall performance was better in Kiboko than at Thika. Cassava Mosaic Disease, Cassava Brown Streak Disease (CBSD) and Cassava Green Mite (CGM) severity were scored on a scale of 1-5. The mean CBSD score was 1.17 in Kiboko and 1.46 in Thika, CMD severity was 1.15 in Kiboko but the disease was not observed at Thika. The CGM damage severity was 1.63 in Kiboko and 1.97 in Thika. The weight of roots per plant was 3.49 and 2.25 kg at Kiboko and Thika, respectively. The dry matter content of the roots was 49.86% at Kiboko and 29.06% at Thika. The cyanogenic potential was assessed using the pictrate test and rated on a scale of 1-9. Kiboko had a score of 2.79 compared to 4.14 in Thika. A total of 91 samples were analyzed for carotenoid content using the spectrophotometry method. The Kiboko site had a higher mean carotenoid content (1736.96 μg/100 g) compared to Thika (1105.85 μg/100 g). Most of the samples (71%) analyzed recorded a higher carotenoid content in Kiboko than Thika. The beta- carotene content was higher in Thika (374.16 μg/100 g) than Kiboko (291.30 μg/100 g). Promising clones adaptable to the two sites were identified.