Spatial arrangement and density effects on an annual cotton/cowpea/maize intercrop. II. Yield and biomass

Field experiments were conducted in 1990 and 1991 in Tucson, Arizona, to examine the effects of spatial arrangement and density on yield and biomass of an annual cotton/cowpea/maize intercrop. In the 1990 experiment, treatments were combined in an unconfounded 4 × 4 factorial, which consisted of four spatial arrangements of cotton, cowpea, and maize crossed with four cowpea/maize densities. In the 1991 experiment, treatments were combined in an unconfounded 5 × 2 + 1 factorial, which consisted of five densities of cotton crossed with two densities of cowpea and maize, plus one additional treatment. The results of these experiments indicate that component-crop yield and biomass in an annual cotton/cowpea/maize intercrop can be significantly affected by the manipulation of spatial arrangement and density as management factors. The most appropriate arrangements and densities in particular circumstances depend on either the combined intercrop yield and biomass or the yield and biomass of a specific component crop that is more highly valued.