Written by:  George Cloutson, Head of Scientific Strategy.

Published: February 2023

Originally published in Bee Culture Magazine.

Successful pollination is critical for a strong almond yield and healthy crop. The amount of bee foraging activity during almond bloom is therefore of considerable interest to growers. Currently, bee pollination activity is inferred from the amount of good bee foraging weather during almond bloom. A Bee Flight Hour is accumulated for each hour that it does not rain, the temperature is above 55℉ and wind speeds are less than 15 mph. The Bee Flight Hours calculation starts when the early cultivars first bloom and runs through petal fall, and is sometimes used as a predictor of nut set, and ultimately yield.

While this concept seems logical, in reality, the situation is much more complicated. There are various factors that will impact bee foraging activity as well as the weather. This includes colony size, brood status, and stage of bloom (forage availability). It is the dynamics of all these factors that determine the number of bee visits received by the blossoms. The application of smart sensor technology and data analytics means it is now possible to directly monitor all these variables to provide accurate, real time tracking of pollination progress. With this aim in mind, California based BeeHero is rolling out a network of strategically placed Pollination Research Stations statewide, covering all major growing regions and cultivars. Each location will be equipped with specialist sensors to monitor the hives, local weather conditions and bloom progress.

• Bee Counters to measure real flying times and the actual number of bee foraging trips.

• In Hive Sensors to monitor colony strength and brood status.

• Hive Scales to track nectar foraging activity.

• Cameras to give visual confirmation of bloom progression.

• Weather sensors to monitor local weather conditions.

The initiative was piloted during 2021 almond pollination, and revealed the highly dynamic foraging behavior of the bees. The Bee Counters continuously and precisely record bee traffic thus providing direct measurement of bee flight hours and the impact of changing weather and bloom status. The sensors showed that bees will sometimes fly in weather conditions outside the

thresholds used for the Bee Flight Hours model, particularly when high-value pollen is available. Thus in this example the real flight hours exceeded the Bee Flight Hours model. The sensors also showed how a Bee Flight Hour can differ significantly in terms of the actual number of foraging trips. During full bloom, colonies performed around 5,000 foraging trips per hour, which

halved to 2-3,000 trips per hour during petal fall, demonstrating the colonies response to the reduction in forage availability. Furthermore, the Hive Scales identified when the bees were nectar foraging and building up honey stores, also a valuable insight for growers and beekeepers. The Pollination Research Stations bring together real time data on bee foraging activity, bloom status and weather conditions, to provide an accurate localized assessment of pollination progress for growers and beekeepers. The initiative will also generate an incredibly rich source

of data that will contribute to the development of more accurate models and metrics for assessing pollination efficacy. In essence, the bees themselves are the ‘sensors’ of the environment, and harnessing the wisdom of the hive can help to improve our understanding and management of one of the most important processes for food production. The data derived from each station will be made available to everyone in the almond industry.

To track your pollination this season head to:

https://growers.beehero.io/ExternalsentinelStations