Dear all, I am trying to assess the effect of five pollination treatments on a plant's fruit set. The data set is not too good (few samples and unbalanced -we lost many field samples to vandalism-, quite a few zeros). I counted the n of flowers that received each treatment and the number of fruits at the end of the experiment. I am using a binomial model, but the results look awkward (from looking at the data I would expect *some* significant effect). I'll be grateful for any advice on how to reliably test the significance of the treatments and do multiple pairwise comparisons. Thanks in advance for your help!
Here is the code to load the data and perform the analysis. I've attached the dataset. #loading data sistrep <- read.table('articulata.csv', sep=",", head=T) str(sistrep) nofruits <- sistrep$flowers - sistrep$fruits #this bit plots the data prop <- sistrep$fruits/sistrep$flowers boxplot(prop ~ treatment, data=sistrep, las=1, ylab="Fruit set (n fruits/n flowers)", boxwex=0.6) #and here is the model M1 <- glm(cbind(fruits, nofruits) ~ treatment, data = sistrep, family = "binomial") summary(M1) --------------------------------------------- Dr. Mariano Devoto Profesor Adjunto - Cátedra de Botánica General, Facultad de Agronomía de la UBA Investigador Adjunto del CONICET Av. San Martín 4453 - C1417DSE - C. A. de Buenos Aires - Argentina +5411 5287-0069 *https://www.researchgate.net/profile/Mariano_Devoto <https://www.researchgate.net/profile/Mariano_Devoto>* _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology