General introduction

Uganda is a land locked country situated between the latitude 4.5°N and 1.5°S. It is bounded to the east by Kenya, to the north by Sudan, to the west by the Democratic Republic of Congo and Rwanda and to the south west by Tanzania. Lake Victoria forms a large part of the southern boundary. The boundaries have profound social and economic influence on those countries adjacent to Uganda with significant implications for trade and political interaction (Bibangambah, 1999). Given that Uganda is situated astride the equator; the climate is basically equatorial though strongly modified by altitude. Because of the equatorial climate, there is little seasonal variation on temperatures i.e. less than 6 degrees variation in the maximum and 3 degrees centigrade in the minimum. Rainfall: Like other countries at the equator, Uganda has two distinct wet and dry periods each year, the ‘first rains in March-May and the ‘Second rains ’ in September-November although northern Uganda has one long rainy season typical of Savannah climate regions. The bimodal rainfall distribution in most parts of the country permits at least two harvests of a crop a year. Only about half of the area of high rainfall is under crops