title: How to check p-value in REML (or mixed model) using lmer() in R?
body: <p>This is my data and I'd like to do REML analysis to see variance components of random factor.</p>
  <pre><code>Plant&lt;- rep(c(&quot;P1&quot;,&quot;P2&quot;,&quot;P3&quot;,&quot;P4&quot;), each=9)
  Leaves&lt;- rep(rep(c(&quot;L1&quot;,&quot;L2&quot;,&quot;L3&quot;), each=3),4)
  Rep&lt;-rep(c(1,2,3),12)
  Ca&lt;- c(3.280, 3.090, 3.185, 3.520, 3.600, 3.560, 2.880, 2.800, 2.840, 2.460, 2.440,
         2.450, 1.870, 1.800, 1.835, 2.190, 2.100, 2.145, 2.770, 2.660, 2.715, 3.740,
         3.440, 3.590, 2.550, 2.700, 2.625, 3.780, 3.870, 3.825, 4.070, 4.200, 4.135,
         3.310, 3.400, 3.355)
  
  tomato&lt;- data.frame(Plant,Leaves,Rep,Ca)
  </code></pre>
  <p>and this is my code</p>
  <pre><code>library(lme4)
  
  lmer &lt;- lmer(Ca ~ (1|Plant)+ (1|Plant:Leaves), REML=TRUE, data=tomato)
  summary(lmer)
  </code></pre>
  <p>I assumed that leaves are nested to plant. So I code as (1|Plant:Leaves)</p>
  <p><a href="https://i.stack.imgur.com/6Oy9K.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6Oy9K.png" alt="enter image description here" /></a></p>
  <p>This result indicates that Plant and leaves account for the most variability in data, while replicates are minor, doesn't it?</p>
  <p>Then, I want to know plant and leave (nested to plant) are significant or not. Where can I find the p-value? or can I add more code to check p-value?</p>
  <p>Or in REML, only variance component is possible for us to check?</p>
  <p>If so, if I choose plant as a fixed factor like below</p>
  <pre><code>lmer &lt;- lmer(Ca ~ Plant+ (1|Plant:Leaves), REML=TRUE, data=tomato)
  summary(lmer)
  </code></pre>
  <p><a href="https://i.stack.imgur.com/o7jr9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o7jr9.png" alt="enter image description here" /></a></p>
  <p>At least, in this mixed model, p-value for plant (= fixed factor) should be presented? isn't it? But, I can't still find it.</p>
  <p>Could you guide me how to analyze the result of REML?</p>