Introduction

Geographically, Kenya is a diverse country with many agro-ecological zones (AEZs). Maize (Zea mays L.) provides basic diet to millions of people in Kenya.  Total land area under maize production is about 1.5 million hectares, with an annual average production estimated at 3.0 million metric tons, giving a national mean yield of 2 metric tons per hectare.  Typically, yields range from 4 to 8 T/Ha in the high potential highlands of Kenya, representing only 50% (or less) of the genetic potentials of the hybrids.  Highland maize varieties are grown on some 40-50% of the total maize area, representing 600,000 – 800,000 Ha. Constraints for maize production include drought, low soil fertility, pests and diseases. Foliar (leaf) and stalk/ear rot diseases and stem-borers cause great losses in maize production in the humid transitional and high tropics of Kenya.

Maize continues to be the most important staple food in Kenya. However, maize production has not kept pace with the population increase, although breeders and agronomists have exploited its genetic potential for yield. Crop protectionists (entomologists, plant pathologists, and weed scientists) have put tremendous effort in identifying the disease and pest problems.  The incidence and severity of most of these pests and diseases can be reduced by chemical control methods ranging from seed dressing to foliar spraying; but host plant resistance provides the most economical management option.