ABSTRACT

Field trials were conducted at the research farm of the National Root Crops Research,

Institute NRCRI), Umudike in 2004/2005 and 2005/2006 cropping seasons to determine

the effect of cowpea planting density on growth, yield and productivity of component

crops in cowpealcassava intercropping system. Cassava at a density of 10,000 plants per

hectare was intercropped with cowpea at four planting densities (20,000; 40,000; 60,000

and 80,000 plants per hectare). Both crops were also planted in monoculture and in

intercrop. The experiment was arranged in a randomized complete block design (RCBD)

with three replications. Leaf area index (LAI) of cassava was highest with the highest

cowpea planting density in 2005/2006, but in 2004/2005 cropping season, both cropping

system and planting density did not influence the LAI. Cowpea LAI was similar in the 2

seasons with the highest planting density (80,000 plants/ha) producing the highest LAI.

Similarly, fresh root yield (t/ha) of cassava was influenced by cropping system and

population density in 2005/2006, but not in 2004/2005 cropping season. Cassava tuber

yield was highest with the cowpea planting density of 80,000 plants/ha. Cowpea grain

yield (kg/ha) was not significantly (P > 0.05) affected by intercropping in the two

cropping seasons. Grain yield of cowpea was highest with the highest cowpea density in

2005/2006 but in 2004/2005 season, there was no cowpea density effect. The relative

yield total, expressed as land equivalent ratio of the two crops was greater than 1 .0 in all

intercrops. At the prevailing market price level (300 per 40 kg for cassava and N20 per

0.6kg for cowpea), cassava intercropped with 80,000 cowpea plants/ha gave a higher

monetary returns than when intercropped with other population densities of cowpea or in

monoculture of the two crops. Similarly, cowpea at highest population density gave the

highest monetary returns.