Taiwo, O. P., Nwonuala, A. I. and Isaiah, B. F. (2020) “Variability in Yield and Yield Components of Selected Pro-vitamin A Maize (Zea mays L.) Varieties in a Humid Environment of Port Harcourt, Nigeria”, Asian Journal of Agricultural and Horticultural Research, 5(3), pp. 1-10. doi: 10.9734/ajahr/2020/v5i330051.