Evaluation of new cassava genotypes for intercropping in a cassava-based system of southeastern Nigeria

Abstract

Twenty-one cassava genotypes were screened for their intercrop performance at Umudike between 1997 and 1998 cropping seasons. The 2-year yield data were subjected to Rank-Summation Index (RSI) and Simple Regression (SR) Techniques with the view to determine the performance of the new cassava genotypes under intercrop and identify suitable cassava genotypes for maize or maize/melon intercrops. Yields of cassava under monoculture were also correlated with their yields under mix-culture. From the RSI, 10 Cassava genotypes were found compatible with maize and melon. A linear function described the relationship between cassava fresh root yield and maize yield with a significant coefficient of determination ((R2) = 0.889 and correlation coefficient ® of 0.94. Significant correlation was also established between sole cassava and intercropped cassava yields (r = 0.52), while a yield depression of between 20 and 60% was recorded in the cassava for the 2 years. Fitting a bi-plot, four distinct groups emerged thus; Group 1 – optimum performance of cassava and maize (12 genotypes), Group II – low yield of cassava and high yield of maize (5 genotypes), Group III – High yield of cassava and low yield of maize (3 genotypes) and Group IV – low yield of both cassava and maize (1 genotype). Most genotypes identified as being compatible for intercropping by the 2 techniques were similar except in few cases. [Niger Agric. J. 33 (2002): 50-59]