Abstract
Field studies were conducted in northeast Nigeria to evaluate the response of early and late-maturing maize varieties infested with natural populations of Striga to different rates of nitrogen (N) fertilizer. There were significant reductions in the number of emerged Striga at 120 kg N ha−1 for the early varieties and at 60 and 120 kg N ha−1 for the late varieties. The number of emerged Striga only significantly differed among the late varieties. Averaged across varieties, grain yield of the early varieties was 144% higher at 60 kg N ha−1 and 192% higher at 120 kg N ha−1 than without added N. For the late varieties the increase in grain yield was 85% higher at 60 kg N ha−1 and 144% higher at 120 kg N ha−1 than without added N. Among the early varieties, TZE COMP4 C3 had significantly lower grain yield than the other varieties. Among the late varieties, grain yields of 8338-1-1 and TZB-SR were significantly lower than in the other varieties. Our results show that the application of 60–120 kg N/ha to Striga resistant or tolerant varieties may reduce damage and increase grain yield. Higher economic rates of return was obtained at N rates of 60–120 kg N/ha than the other rates.
Acknowledgements
We thank the Canadian International Development Agency for funding the project Promoting Sustainable Agriculture in Borno State, which financed this study, and Rose Umelo for editorial assistance.