Abstract
The effects of three Solanum potato population densities (33, 24.75 and 16.50 × 103 stands ha-1) and four maize population densities (33, 24.75, 16.50 and 8.25 × 103 stands ha-1) on yields of potato tuber and maize grain, nett income and total productivity were studied in a field experiment at Jos, Nigeria, in 1984 and 1985. Total potato tuber yield at each planting density declined with increasing plant density of maize. Sole potato gave significantly higher tuber yield than any potato/maize combination. Maize yield was not affected by potato population density. Sole potato gave the highest nett return (? 3407 ha-1) which was significantly higher than ? 742 from sole maize. Nett return from sole potato was not significantly higher than that from other potato/maize combinations. LER was increased with intercropping. A LER of 1.61 was obtained at a combination of the highest population densities of both crops. For all variables the interactions of the population density of maize and potato were not significant. Mean maize yields were significantly higher in 1984 (2.69 t ha-1) than in 1985 (1.75 t ha-1); mean potato yields in 1985 (12.1 t ha-1) were 82% higher than the mean yields in 1984.
