Twelve cassava (Manihot esculenta crantz) genotypes were grown at two field sites in Nigeria representing lowland and mid-altitude agroecological zones from 1994 to 1996 (Ibadan and Jos). Leaf area development and dry matter partitioning were studied by the destructive growth analyses at 3, 6, 9, and 12 months after planting (map). At Ibadan, leaf area index (lAI) was 3.6 and 2.1, while at Jos LAI value of 0.5 and 2 were observed at 6 and 12 maps respectively, during 1994/95 crop season. At Jos, dry matter production was significantly lowered as compared with Ibadan. This was contributed to a lower temperature regime and lower radiation levels at the Jos Plateau. Patterns of dry matter practitioning to leaves, shoots, and roots were similar in both sites. Dry matter partitioning to storage roots was controlled by plant age and radiation factors while partitioning to leaves was a function of plant age and temperature at both altitude. Our data therefore show that at mid-altitude, partitioning of dry matter to roots versus leaves is a function of radiation and temperature. These plant parameters can be used to validate growth models of cassava suited for the mid-altitude of Africa.

Genetic Improvement; Cassava; Food Security; Climate Change

Cassava; Genotypes; Temperature

Africa; West Africa

Nigeria