Yield effects of intercropping white guinea yam (Dioscoreae rotundata P.) minisetts and maize (Zea mays L.) in the southern Guinea savanna of Nigeria

Abstract

Field experiments were conducted from May to October during 2003 and 2004 cropping seasons at the Research Farm, University of Agriculture, Makurdi, Benue State, Nigeria, to evaluate the yield effects of intercropping white Guinea yam (minisetts) and maize and to assess the advantages of the intercropping system. Maize yield was not significantly affected by intercropping with yam-minisett. However, tuber yield of yam-minisetts intercropped with maize was significantly (P≤0.05) depressed by 15.0 and 16.3% respectively, in 2003 and 2004 compared to monocultured yam-minisett. However, total yield was greater than the component crop yield, either planted as sole or in mixture. Intercropping yam-minisett and maize gave land equivalent ratio (LER) values of 1.98 and 1.95 respectively, for years 2003 and 2004, thus, indicating that higher productivity per unit area was achieved by growing the two crops together than by growing them separately. With these LER values, 49.5 and 48.7% of land was saved respectively, in 2003 and 2004, which could be used for other agricultural purposes. In addition, maize was about three-quarters as competitive as yam-minisett, indicating that both crops are complimentary and suitable in mixture. Key words: White guinea yam, minisetts, maize, intercropping, Nigeria.