title: ANOVA and Blocking Design
body: <p>I have a field experiment carried out with trees in which we have planted different genotypes in a little plantation following a randomized complete block design (RCBD). 
  Now I want to do the analysis in R but I have some doubts about how to do it. 
  In a nutshell, I have 3 blocks and 5 genotypes, in addition to several variables we've measured, one of those is HEIGHT. The code I am using to do the ANOVA test is:</p>
  
  <pre><code>fit &lt;- lm(HEIGHT~GENOTYPE+BLOCK,data=data)
  
  anova(fit)
  </code></pre>
  
  <p>In some webpages I've seen that they write: </p>
  
  <pre><code>lm(HEIGHT~BLOCK+GENOTYPE,data=data)
  </code></pre>
  
  <p>I don't know which is exactly the difference but I've tried both linear models (lm) and the results are not the same. The question is very simple: why? What is exactly what I'm telling to R when I write "Height~Genotype+Block" and when I'm telling "Height~Block+Genotype"? The other question is: Am I doing the blocking ANOVA correctly?</p>
  
  <p>Thank you very much in advance!! </p>