Chilling and Forcing From Cut Twigs-How to Simplify Phenological Experiments for Citizen Science

Area of Science:

• Plant phenology
• Climate change biology
• Citizen science

Background:

• Bud development is crucial for plant life cycles.
• Winter chilling is a key environmental factor influencing bud burst.
• Current methods for studying chilling requirements can be resource-intensive.

Purpose of the Study:

• To investigate the efficacy of low-cost cut twig experiments for studying winter chilling requirements.
• To assess the feasibility of implementing these experiments in citizen science and school settings.
• To develop a robust experimental protocol for phenological research.

Main Methods:

• Experiments using *Corylus avellana* (hazel) cut twigs subjected to natural and refrigerated chilling treatments.
• Forcing of twigs indoors to observe bud burst and leaf development.
• Statistical analysis to determine minimum sample sizes and model the chilling-forcing relationship.

Main Results:

• Cut twig experiments accurately reflected natural chilling conditions.
• A negative exponential relationship was found between chilling duration and forcing required for bud burst.
• Minimum sample sizes were identified for robust data collection (e.g., 5 cutting dates or 10 twig repetitions).

Conclusions:

• Low-cost cut twig experiments are a viable method for studying winter chilling and bud development.
• The methodology is well-suited for citizen science, school projects, and science education.
• Large-scale implementation can significantly advance phenological research and climate change impact studies.