RESPONSE OF CASSAVA AND MAIZE TO FERTILIZER APPLICATION, AND A COMPARISON OF THE FACTORS AFFECTING THEIR GROWTH DURING INTERCROPPING

A field experiment was conducted on a Paleustalf to examine the effect of fertilizer application and the possible yield limiting factors in a cassava-maize intercropping system. Application of N-fertilizer sign ificantly increased maize grain and cassava root yields as well as N, P and K concentrations of both crops compared with application of non- N fertilizer or with the unfertilized controls, Intercropping, with or without fertilizer application, led to a decrease in the root yield a nd N, P and K concentrations of cassava, but had no significant effect on nutrient concentrations and grain yield of maize. Growth analysis revealed that from 20 weeks after planting to harvest in cassava and d uring the flowering to harvest in maize dry matter accumulation in bot h crops was similar in intercropping. However, during the same period, the mean crop growth rate in cassava was less than a fourth of the me an crop growth rate in maize. It was concluded that the main factor li miting total yield in a cassava-maize intercropping system is the depr ession of early cassava growth by vigorous maize component, which redu ces the amount of assimilate allocated to cassava roots.