[R] [off-topic] The better analysis

[Ronaldo Reis Jr.]

Hi all,
Firstly excuse-me by this off-topic question.

I'm very confused to decide what is the better analysis to use.
Whem the experiments is a tradicional design of manipulative experiments, it 
is easy to decide. But in natural observations is too complicated.

I have 6 farms, each farm cultives some sugarcane's varieties (maybe or not 
the same varieties by farm). For each farm I make 3 transects (lines) 
(replicates) crossing all varieties, and I make one collect point in each 
variety. 

Example:
In farm "A" I have 3 varieties and I make 3 transect, so I have 3*3 = 9 
points. In each collect point all data are obtained independently.

The data are:

* production (my response)

My explanatory variables are:

* sugarcane's variety (categorical, not necessarily the same on all farms)
* age of sugarcane (continuous, not necessarily the same on all farms)
* name of farm (block ??)
* topography (categorical, not necessarily the same on all farms)
* infestation (continuous, the main explanatory variable)

I think make a modelo like this:

lm(production~variety*age*farm*topography*infestation)

My doubt is about the errors, I dont get to know if this is nested, mixed etc.

Anybody can help-me.

Thanks for all
Ronaldo
-- 
Short people get rained on last.
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