Identified Major Disease Hazards of Maize Production in Southern Nigeria

Abstract

Disease rating of naturally infected 481 local maize cultivars collected from 8 states in the rainforest and parts of the Guinea Savanna zones of Nigeria revealed that rust infection caused by Puccinia polysora was an important hazard to maize production in southern Nigeria. Out of the 481 cultivars planted 378 had 31-70% total leaf area infected by rust (P. polysora). This means that on the average 78.6% of the total plantslplot (ten plantslplot) were infected by rust. Similarly, about 133 cultivars had leaf blight infections caused by H. maydis; this corresponded to 1-30% total leaf area infected. The two improved varieties on the average had 65% of the total plants/plot infected by rust. Disease incidence and severity of the other pathogens on the improved varities were generally low. Rust epiphytotics are, therefore imminent in southern Nigeria if not checked adequately and fast. Other maize disease hazards identified in order of their importance were H. maydis, Curvularia and Fusarium spp, H. turcicum, stem borer and maize streak virus. The solution to the problems includes use of resistant varieties, well planned maize production prograrnme, and chemical control measures. To avoid maize disease epiphytotics in the rainforest and parts of the Guinea Savanna vegetations zones of Nigeria it is recommended that research institutes and universities involved in maize irhprovement prograrnme should emphasize maize disease problems in maize production and in their research proposals or Programmes.