R: Competition between two biotypes

RScompetition {drc} | R Documentation

## Competition between two biotypes

### Description

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.

### Usage

    data(RScompetition)

### Format

A data frame with 49 observations on the following 3 variables.

`z`

  a numeric vector with densities of the resistant biotype (plants/m2)

`x`

  a numeric vector with densities of the sensitive biotype (plants/m2)

`biomass`

  a numeric vector of biomass weight (g/plant)

### Details

A hyperbolic model (Jensen, 1993) is describing the data reasonably well.

### Source

The dataset is from Pedersen et al (2007).

### References

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.

[Package drc version 3.0-1 Index]