Hello,

I have a mixed model for Canopy temperature (CT). which is as following.

For CT, we have 100 observations for one single trial area as data was recorded repeatedly from plots. In this case, we considered the structure of the repeated measures within the model. In a replicate, we have five blocks and in one block we have five plots. So, we have ten blocks and 50 plots in total. In each plot, there are two measuring times. So, our data was sorted by blocks, plots within blocks and measuring times within plots. the model was as following,

CTijkh = m + gj +ti + bih+ pijh +eijkh,

where,

CTijkh = response of i-th genotype in h-th block within j-th replicate with k-th time points

m = intercept

gj=effect of j–th complete replicate

ti = effect of i-th genotype

bjh =effect of h-th block nested within j–th complete replicate

pijh = plot effect of....

eijkh = residual error associated with Ctijkh.

Now, I want to add two more covariates to the model (say A&R). what will be the model with covariates and how should I describe this?