Effect of altitude on maize protein in equatorial environment

Twenty maize (Zea mays L.) hybrids and composites submitted for the East African Maize Variety Trial and the National Maize Variety Trial have been screened for protein content and to a limited extent for protein quality in relation to environment. Content of crude protein in improved varieties developed in Tanzania increased slightly with increase in altitude near the equator. No significant increase was observed in lysine and tryptophan levels. Percentages of protein were affected by both variety and environment. The lowest and highest protein percentages as due to environment ranged from 4.812 arid 11.652, respectively. Positive significant correlation between grain yield and gross protein yield par unit area and negative correlation between grain yield and per cent protein content indicate the possibility of selection for yield in combination with medium-high levels of protein.