2021 Regional Bee Hours Report
Find out how your region’s bee hours are accumulating compared to last season and see your forecasted bee hours for the rest of the pollination season. This chart references anonymous in-canopy Semios weather stations across the Central Valley and is updated every 12 hours.
Use the green left and right arrows on the chart below to scroll through North Valley, Mid Valley, and South Valley bee activity.
See your site-specific bee hours on Semios Live
Bee hours that are accumulated during the bloom overlap period should be used to assess pollination during bloom. It is best to use bloom progression as observed from the field, however for almond growers who do not have that information on hand, Semios provides predictions of bloom periods for Nonpareil and Monterey varieties on the Semios pollination dashboard.
Understanding Bee Hours
Bee hours tell you are the hours in which conditions are favorable for bees to fly.
A bee hour is defined as one hour where:
- There is no rain
- The temperature is warmer than 55° F, and
- Wind speeds are less than 15 mph
More bee activity means more opportunities for pollination, making bee hours a useful metric for getting a sense of how fruit or nut set, and ultimately yield, may compare between years.
Three ways to use bee hours
1. Adjusting bloom period
In crops that require cross pollination such as almond, bee hours are only effective when bloom between different varieties overlap. Shorter bloom overlap can mean a shorter period where bee hours can accumulate. In years where bee hours are high, this may not be an issue, but in years where bee hours are low, you may want to consider taking action to extend the bloom period.
2. Plan your bloom-time sprays
Chemical applications should be avoided when bees are active in the orchard. It is recommended to limit spray applications to the late afternoon and evenings to target periods when bees are inactive. An extra level of assurance can be achieved by only spraying when bee hours are not expected to accumulate.
Semios customers can use their Pollination Dashboard to view their orchard’s forecasted bee active hours and plan sprays when bees aren’t present.
3. Troubleshooting poor fruit or nut set
After the bloom season, bee hours can help you troubleshoot what went right and what went wrong. If you had more bee hours this season but poor fruit set compared to a previous year with less bee hours, there may be something else that may be going on in your orchard.
This article is for informational purposes only. Please consult your PCA or Crop Advisor for advice.