The Yield, Canopy Structure and Light Interception of Two Ryegrass Varieties in Mixed Culture and Monoculture

Two experiments were carried out to measure the yield, canopy structure and light interception of S23 and Ba 6280 perennial ryegrass in monoculture and mixed culture. The mixed culture outyielded both monocultures only under frequent cutting and a high fertilizer regime. Measurements of canopy structure and light profiles within the canopies under these latter treatments indicated that the greater residual leaf area after defoliation in S23 and in the mixture may have resulted in their superior production compared with Ba 6280. The fact that a greater percentage of the intercepted light energy was distributed over the most photosynthetically efficient tissue may explain the higher production of the mixture when compared with S23 in monoculture.