Abstract
High-throughput plant phenotyping is increasingly implemented in a wide
array of experimentation and presents challenges both logistically and
analytically. Phenotype data are often longitudinal and proper modeling
of plant growth requires sophisticated modeling techniques to account
for the intra-plant correlations and changing variation over time
(heteroskedasticity). For this reason, plant growth is often analyzed by
comparing only single time points or the start and end points for
inference with no regard for the trends themselves. Single time point
analysis can be sufficient for simple biological comparisons, but
modeling has the potential to unlock additional insights by utilizing
all the information at hand. Current plant growth modeling strategies do
account for intra-plant correlations but are still limited to constant
variance assumptions and therefore perform sub-optimally. Here we
propose a Bayesian hierarchical approach as an alternative method for
plant growth modeling by demonstrating the utility of heteroskedastic
sub-model parameterizations. We show that accounting for
heteroskedasticity greatly improves model accuracy and subsequent
inference. Additionally, Bayesian methodologies inherently lend
themselves to near real-time model updating and we propose integration
with Clowder to facilitate adaptive experimental designs. We show by
example the utility of Bayesian updating and how it relates to
experimental decision making.