Evaluation of Maize Varieties for VCU and Dus in Nigeria.

The ultimate goal of crop breeding programs is to develop and release improved varieties for farmers’ use. In Nigeria, there is a National Varietal Release and Registration Committee (NAVRRC) served by a Technical sub-Committee (TSB) that evaluates all applications and candidate varieties for release. To prevent similar varieties from being proposed for released by different breeders or institutions, TSB has stipulated compliance with the rules of value for cultivation and use (VCU) and distinctness, uniformity and stability (DUS) for varieties to be released. Plant breeders in Nigeria have access to the same germplasm resource centers for developing improved varieties of maize (Zea mays L.). The objective of this study was to evaluate the improved early and extra-early varieties of maize for VCU and DUS in the rainforest agroecology of sw Nigeria, with a view to classifying the varieties into different breeding groups. Forty early and extra-early varieties were evaluated at the Teaching and Research Farm of Obafemi Awolowo University, Ile-Ife, Nigeria in 2013 and 2014. A total of 17 VCU and 23 DUS traits were assayed in the trials, and the data were subjected to ANOVA, PCA and Cluster analysis. Significant differences occurred for very few VCU traits, unlike DCU traits which showed significant differences for many traits. In 2013, the varieties were grouped into four clusters each for VCU and DUS, while in 2014, there were three groups based on VCU and five for DUS. It was concluded that classification of breeding populations on the basis of VCU and DUS traits should facilitate the development of distinct new maize varieties for farmers in Nigeria.