From Shaun (29/10/2012):
Geoff Inman-Bamber uses these manager rules. (See the word document attached)
I think that I had to add them to some simulations he wanted me to run.
I think that they tweak the model to make irrigation and lodging a bit more realistic.
I guess we should really be changing the source code instead of adding manager rules.
I thought it might be good to add them to the Sugar Toolbox so that all users would have access to them.