Development of Striga asiatica tolerant hybrid maize {Zea mays L.), varieties

Abstract

Eighteen maize (Zea mays L.) Lines including nine Striga asiatica tolerant inbreds and nine agronomically desirable (but not necessarily tolerant) inbreds were used in a non-reciprocal diallel cross. The selected FI hybrids were evaluated twice in the Striga asiatica endemic area under artificial infestation. Significant differences were recorded in plant and ear heights, silking and tasselling days under infestation and noncount infestation. Striga emergence count ranged between 0.62 and 1.69, while, tolerance rating varied between 3.0 and 4.17. Tolerance advantages of between 0.12 and 0.25 have resulted in a yield increase of between 13.4% and 27.8%. Yield advantage, tolerance index and, tolerance advantages were also found to be reliable parameters for the assessment of striga tolerance in maize. High mid-parent heterosis of between 76.0 and 88% was obtained for seed yield, especially in hybrids 9601,9602 and 9618. From this study, five striga tolerant hybrid maize varieties were identifed. The hybrids (9601, 9602, 9603, 9605 and 9607 exhibited tolerance index of above 0.75, with % yield increase of 13.4, 19.24,14.1,27.8 and 13.4 respectively. These hybrids may be desirable for cultivation in the striga endemic areas of South Western Nigeria.