Understanding Chill in Pistachios
A Microclimate and Chill Accumulation Case Study
Chill is required for leaf and flower bud development in many fruit and nut trees. 'Industry research has determined a lack of sufficient hours below 45° F affects the nut crop that develops in the spring. There can be poor fruit bud development, delayed or strung out bloom and poor overlap with pollinators'. The ability to set a crop can be affected as well as maturity timing resulting in need for multiple harvests. As we enter spring and the end of chill accumulation, we have many customers wondering why their chill hours can differ so much from the regional weather stations.
In some cases, the difference in chill in their own orchard can even be more pronounced than between their own stations and a neighbor’s.
The reasons for this can be attributed to
- Microclimate variation and
- Temperature fluctuation sensitivities between chill models.
A Chill Accumulation Case Study in Pistachios
One of our pistachio-growing customers that has five weather stations across their property noticed last year that there were some differences between their chill hours and chill portions.
Two weather stations had accumulated chill hours in the 300 range, while the other two had over 500 chill hours accumulated. Meanwhile, their chill portions across all stations were sitting at approximately 35.
How do chill hours accumulate?
Chill hours are the number of hours when the temperature drops below 45 °F, or is between 32 - 45 °F, depending on the model you use.
Let’s look at the temperature over time at two of their weather stations.
Station A has accumulated 326 chill hours, and 37 chill portions and Station B has accumulated 589 chill hours, and 39 chill portions.
-
Most popular related searches
Customer comments
No comments were found for Understanding Chill in Pistachios. Be the first to comment!