Use of Thermal Time to Predict Phenology of Kenyan Maize Germplasm.

Abstract

Maize is the major cereal crop in Kenya and is and regions (Wafula and Keating, 1990), and grown at altitudes from sea-level to above 2800 applied to an analysis of the risks associated with m. Temperatures are strongly correlated with plant population and nitrogen management altitude in this equatorial region (Griffiths, strategies (Keating et al., 1989). 1972); mean annual temperatures in maize growing areas range from 13 to 27 C. Rainfall regimes The wider application of such models requires that they adequately simulate the variation in vary greatly across the country, from the semicrop growth and development that arises from arid eastern midlands with less than 250 mm rainfall expectation in a very short season, to the the use of different germplasm in different agro-ecozones. The objective of this study was to humid central highlands which receive more than 1600 mm over a much longer growing season. examine how genotype and environment affect A diverse range of germplasm has been de-maize growth and development. This was done to veloped within Kenya (Harrison; 1970) to pro-evaluate the predictive routines currently used to vide adaptation to a wide range of agro-simulate various growth and development proecozones. cesses. Some information was already available (Cooper, 1979) but this was restricted to one The relationships between altitude, tempera-cultivar and was not specifically targetted toture and maize growth have been studied in wards simulation.