Determining the Risk Window for Aster Yellows in Carrot: New ...

Part I: variance component analysis
The objective of this analysis is to estimate variances not to
detect differences
Factors associated with leafhopper abundance and infectivity
were considered to be random effects (RE)
RE were structured to deal with implicit nesting (i.e. day is
nested in year)
Models were fit by maximum likelihood using lmer function in
the lme4 package of R
Likelihood ratio tests (LRT) were used to compare mixed
effects models