Visualizing N-way frequency table as a Decision Tree in R
You could try

library(data.tree)
test$pathString &lt;- with(test, paste("lm", Type, Treatment, round(res, 2), sep="/"))
(tree &lt;- as.Node(test))
#             levelName
# 1  lm                
# 2   ¦--Quebec        
# 3   ¦   ¦--nonchilled
# 4   ¦   ¦   °--36.97 
# 5   ¦   °--chilled   
# 6   ¦       °--30.11 
# 7   °--Mississippi   
# 8       ¦--nonchilled
# 9       ¦   °--24.31 
# 10      °--chilled   
# 11          °--17.45 
plot(tree)


The plot uses the DiagrammeR package.