Consider a 3 ×3 factorial experiment in randomized blocks, with 4 replications, on the influence of three new soybean cultivars (A1, A2 and A3) and the use of three types of green manure (B1, B2 and B3) on yield in 100 m2 plots.
data.frame containing data set
Categorical vector with cultivars
Categorical vector with green manure
Categorical vector with block
Numeric vector with yield