chillR-package

<code>chillR</code> contains functions for processing temperature records into chilling (Chilling Hours, Utah Chill Units
and Chill Portions) and heat units (Growing Degree Hours). Regarding chilling metrics, Chill Portions are often
considered the most promising, but they are difficult to calculate. This package makes it easy.
<code>chillR</code> also contains procedures for conducting a Partial Least Square regression analysis relating
phenological dates (e.g. bloom dates) to either mean temperatures or mean chill and heat accumulation rates,
based on long-term weather and phenology records (Luedeling and Gassner 2012).
As of version 0.65, it also includes functions for generating weather scenarios with a weather generator,
for conducting climate change analyses for temperature-based climatic metrics and for plotting results from such
analyses. Since version 0.70, <code>chillR</code> contains a function for interpolating hourly temperature records.
As of version 0.72.6, the package contains functions to design elegant plots using the <code>ggplot2</code> package.

The phenology of plants (i.e. the timing of their annual life
phases) depends on climatic cues. For temperate trees and many other plants,
spring phases, such as leaf emergence and flowering, have been found to result
from the effects of both cool (chilling) conditions and heat. Fruit tree
scientists (pomologists) have developed some metrics to quantify chilling
and heat (e.g. see Luedeling (2012) <doi:10.1016/j.scienta.2012.07.011>).
'chillR' contains functions for processing temperature records into
chilling (Chilling Hours, Utah Chill Units and Chill Portions) and heat units
(Growing Degree Hours). Regarding chilling metrics, Chill Portions are often
considered the most promising, but they are difficult to calculate. This package
makes it easy. 'chillR' also contains procedures for conducting a PLS analysis
relating phenological dates (e.g. bloom dates) to either mean temperatures or
mean chill and heat accumulation rates, based on long-term weather and phenology
records (Luedeling and Gassner (2012) <doi:10.1016/j.agrformet.2011.10.020>).
As of version 0.65, it also includes functions for generating weather
scenarios with a weather generator, for conducting climate change analyses
for temperature-based climatic metrics and for plotting results from such
analyses. Since version 0.70, 'chillR' contains a function for interpolating
hourly temperature records.

Eike Luedeling

chillR

Statistical Methods for Phenology Analysis in Temperate Fruit
Trees

Lars Caspersen

Eduardo Fernandez

chillR-package function

<table class="table">
<tr><td>Prof. Dr. Eike Luedeling (creator)</td><td><a href="/link/eike%40eikeluedeling.com?package=chillR&version=0.75" data-mini-rdoc="chillR::eike@eikeluedeling.com">eike@eikeluedeling.com</a></td></tr>
<tr><td><a href="https://orcid.org/0000-0002-7316-3631">ORCID</a></td><td><a href="https://github.com/eikeluedeling">eikeluedeling on GitHub</a></td></tr>
<tr><td></td><td>Lars Caspersen (contributor)</td></tr>
<tr><td><a href="/link/lcaspers%40uni-bonn.de?package=chillR&version=0.75" data-mini-rdoc="chillR::lcaspers@uni-bonn.de">lcaspers@uni-bonn.de</a></td><td><a href="https://orcid.org/0009-0000-3057-7327">ORCID</a></td></tr>
<tr><td><a href="https://github.com/larscaspersen">larscaspersen on GitHub</a></td><td></td></tr>
<tr><td>Dr. Eduardo Fernández (contributor)</td><td><a href="/link/eduardo.fernandez.c%40pucv.cl?package=chillR&version=0.75" data-mini-rdoc="chillR::eduardo.fernandez.c@pucv.cl">eduardo.fernandez.c@pucv.cl</a></td></tr>
<tr><td><a href="https://orcid.org/0000-0002-6949-9685">ORCID</a></td><td><a href="https://github.com/EduardoFernandezC">EduardoFernandezC on GitHub</a></td></tr>
</table>

Author


chillR: statistical methods for phenology analysis in temperate fruit trees — chillR-package

<table class='table'>
<tr><td>Prof. Dr. Eike Luedeling (creator)</td><td><a href='mailto:eike@eikeluedeling.com'>eike@eikeluedeling.com</a></td></tr>
<tr><td><a href='https://orcid.org/0000-0002-7316-3631'>ORCID</a></td><td><a href='https://github.com/eikeluedeling'>eikeluedeling on GitHub</a></td></tr>
<tr><td></td><td>Lars Caspersen (contributor)</td></tr>
<tr><td><a href='mailto:lcaspers@uni-bonn.de'>lcaspers@uni-bonn.de</a></td><td><a href='https://orcid.org/0009-0000-3057-7327'>ORCID</a></td></tr>
<tr><td><a href='https://github.com/larscaspersen'>larscaspersen on GitHub</a></td><td></td></tr>
<tr><td>Dr. Eduardo Fernández (contributor)</td><td><a href='mailto:eduardo.fernandez.c@pucv.cl'>eduardo.fernandez.c@pucv.cl</a></td></tr>
<tr><td><a href='https://orcid.org/0000-0002-6949-9685'>ORCID</a></td><td><a href='https://github.com/EduardoFernandezC'>EduardoFernandezC on GitHub</a></td></tr>
</table>

<img src='figures/chillR.png' width='25%' alt='chillR logo' />
chillR: statistical methods for phenology analysis in temperate fruit trees

<img src="figures/chillR.png?package=chillR&version=0.75" width="25%" alt="chillR logo">
chillR: statistical methods for phenology analysis in temperate fruit trees

chillR-package: chillR: statistical methods for phenology analysis in temperate fruit trees

Description

Arguments

Author

References

Prof. Dr. Eike Luedeling (creator)	eike@eikeluedeling.com
ORCID	eikeluedeling on GitHub
	Lars Caspersen (contributor)
lcaspers@uni-bonn.de	ORCID
larscaspersen on GitHub
Dr. Eduardo Fernández (contributor)	eduardo.fernandez.c@pucv.cl
ORCID	EduardoFernandezC on GitHub