Vitamin A deficiency (VAD) is a major public health concern for communities that depend mainly on cassava for their daily carbohydrate requirements. About 50% of Nigerians eat cassava at least once a day in various forms while 60% of children under the age of five and 20% of pregnant women in the country are faced with VAD. Therefore, breeding for enhanced pro-vitamin A in cassava to address both food and nutrition security is an important goal. This study was carried out to evaluate selected yellow root cassava (YRC) genotypes to dry matter content (DMC), fresh root yield (FRY) and, response to important cassava diseases(cassava mosaic disease, cassava bacteria blight and cassava anthracnose disease) at three agro-ecologies in Nigeria. Ten YRC genotypes and two check varieties (TMS30572 and TMS011368) were evaluated in a randomized complete block design with three replications. There were significant differences among the genotypes for cassava bacteria blight (CBB) and cassava anthracnose disease (CAD) and across location (L), genotypes (G) and genotype by environment (G x E) interaction for cassava mosaic disease (CMD) at P<0.001. There were alsosignificant differences among the genotypes for FRY, DMC and dry root yield (DRY) at P<0.001. The FRY ranged from 4.37 to 31.42with a mean of 11.79t/ha; 1.71 to 21.41with a mean of 7.45; and 3.54 to 35.83with a mean of 24.51t/ha at Umudike, Otobi and Igbariam, respectively. Dry matter content ranged from 25.9 to 31.4 with a mean of 28.5; 20.1 to 36.1% with a mean of 30.48; and 23.8 to 37.3% with a mean of 33.2% at Umudike, Otobi and Igbariam, respectively. Significant correlation was observed among the parameters evaluated.

Keywords: Biofortification, cassava, genotypes, multilocational trial, yellow root