To assess the competitive ability between two biotypes of Lolium rigidum, one resistant to glyphosate and the other a sensitive wild type, the density of resistant and sensitive biotypes was counted after germination.
A data frame with 49 observations on the following 3 variables.
a numeric vector with densities of the resistant biotype (plants/m2)
a numeric vector with densities of the sensitive biotype (plants/m2)
a numeric vector of biomass weight (g/plant)
A hyperbolic model (Jensen, 1993) is describing the data reasonably well.
The dataset is from Pedersen et al (2007).
Jensen, J. E. (1993) Fitness of herbicide-resistant weed biotypes described by competition models, Proceedings of the 8th EWRS Symposium, 14-16 June, Braunschweig, Germany, 1, 25–32.
Pedersen, B. P. and Neve, P. and Andreasen, C. and Powles, S. (2007) Ecological fitness of a glyphosate resistant Lolium rigidum population: Growth and seed production along a competition gradient, Basic and Applied Ecology, 8, 258–268.