Abstract
Correlation coefficients were computed between petiole nutrient variables and seed yield of cowpea (Vigna unguiculata) grown on an acid upland soil in Sierra Leone. The secondary nutrients gave stronger positive correlations with yield than did the primary nutrients. Magnesium and calcium contents accounted for 58 and 50 per cent respectively of the total variation in yield; the nitrogen x magnesium interaction accounted for 67 per cent of yield variation.
