drc (version 1.5-2)

S.alba: Potency of two herbicides

Description

Data are from an experiment, comparing the potency of the two herbicides glyphosate and bentazone in white mustard Sinapis alba.

Usage

data(S.alba)

source

Christensen, M. G. and Teicher, H. B. and Streibig, J. C. (2003) Linking fluorescence induction curve and biomass in herbicide screening, Pest Management Science, 59, 1303--1310.

Details

The lower and upper limits for the two herbicides can be assumed identical, whereas slopes and ED50 values are different (in the log-logistic model).

See Also

See the examples in the examples sections in drm and SI.

Examples

## Fitting a log-logistic model with
##  common lower and upper limits
S.alba.m1 <- drm(DryMatter~Dose, Herbicide, data=S.alba, fct = LL.4(),
pmodels=data.frame(Herbicide,1,1,Herbicide), adjust="bc1") 

## Plotting fitted regression curves together with the data
plot(S.alba.m1)