EFFECTS OF NITROGEN SUPPLY ON CASSAVA PIGEONPEA INTERCROPPING WITH 3 CONTRASTING CASSAVA CULTIVARS

Three cassava cultivars of contrasting canopy size were grown as a sole crop and in intercropping with pigeonpea under two N supply levels to examine whether the effect of N fertilizer was different in sole crop cassava and in intercropping, and whether it depended on the canopy type of cassava cultivar. Application of N promoted plant height and canopy width of cassava in both cropping systems, and this resulted in increased competitiveness of cassava in intercropping. However, when the most vigorous cassava cultivar was used in intercropping, N supply caused excessive top growth with no increase in tuber yield. The yield of pigeonpea on the other hand was always reduced with N supply in intercropping with any cassava cultivar.