RScompetition              package:drc              R Documentation

_C_o_m_p_e_t_i_t_i_o_n _b_e_t_w_e_e_n _t_w_o _b_i_o_t_y_p_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     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.

_U_s_a_g_e:

     data(RScompetition)

_F_o_r_m_a_t:

     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)

     '_b_i_o_m_a_s_s' a numeric vector of biomass weight (g/plant)

_D_e_t_a_i_l_s:

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

_S_o_u_r_c_e:

     The dataset is from Pedersen et al (2007).

_R_e_f_e_r_e_n_c_e_s:

     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.

