Intercropping of cassava ( Manihot esculenta) with maize or cowpea under different row arrangements

Abstract

The effects of various intercropping arrangements of cassava ( Manihot esculenta Crantz) and maize ( Zea mays L.) or cowpeas ( Vigna unguiculata L. Walp) on crop yields were compared over a 3-year period in Nigeria, in an attempt to improve grain yields of the maize and cowpea intercrops without substantially reducing the cassava root yield. Sole-cropped cassava produced the largest yield; this was significantly reduced by about 40% when intercropped with maize or cowpeas but only when using a 1:2 (cassava:intercrop) row arrangement, mainly because of a reduction in its population density. Cassava yield differences among different row arrangements were more marked when grown with maize than with cowpeas. Maize and cowpea grain yields were reduced by intercropping, but somewhat less so when grown with cassava in widely spaced rows. Cassava row spacing did not affect maize yield, but cowpea yield was affected significantly. Land Equivalent Ratios were always greater than 1, irrespective of the crop combinations and row arrangements. However, increased yields of intercropped cassava:maize were obtained at 1:1 or 2:2 row arrangements and of cassava:cowpea at 2:2 rows, without much reduction in cassava tuber yield.