UMaine Wild Blueberry Conference Follow-Up

April 2026

Conference Follow-Up

At this year’s UMaine Wild Blueberry Conference 110 farmers and agricultural service providers came together to commiserate, celebrate, and plan ahead. We talked about so many good ideas and recent research findings. Presentation recordings can be found here.

Updated Factsheets will be available soon.

News Center Maine and the Ellsworth American covered the event in case you missed it.

Forced Air Cooling

In my opinion, one of the most impactful topics discussed was forced air cooling as a low cost way to improve fresh pack quality on the farm. This presentation, developed by Ron Howard, Dr. Lily Calderwood, and Chris Callahan, detailed a forced-air cooling solution designed to address the issues of field heat and therefore, wet berries in harvested fruit. When fruit is harvested it remains alive. This means that harvested fruit continues to burn its own oxygen and sugars, releasing carbon dioxide, water vapor, and heat. This is called respiration. As a farmer growing very high quality fresh fruit, your job is to slow down this respiration process by lowering the temperature of the fruit as quickly as possible.

Funded by a NE SARE Farmer Grant, the forced air cooling system at Brodis Blueberries was constructed for a total material cost of $6,720. The system was based on the concepts of forced air cooling explained here and an enlarged version of the one pallet system was built.  The image above shows the final forced air cooler at Brodis Blueberries and expenses are listed in Table 1.  The wild blueberry setup utilized a plywood plenum, a vinyl-coated tarp to seal the top and back, and pool noodles to manage airflow. By creating a 16–24 inch airflow tunnel, the blower drew air through the fruit bins, supported by room heat pumps set at 65F providing 14,500 BTU/hr of cooling and removed approximately 4 pints of moisture per hour.

Item	Total Cost
12 U-boat Carts	$4,245
Tarp	$145
Plywood	$195
Paint	$10
Suction Blower	$2,125
Total Material Cost	$6,720

Trial results demonstrate that the system is highly effective. It reduced fruit temperature to room temperature in less than two hours. Proper sealing was found to be critical; when gaps were sealed with poly film in the second trial, air velocity through the center of the bins increased from 135 to 193 ft/min. Beyond cooling, the system significantly aids in drying, with bins losing an average of 0.73 lbs of water during the dry 2025 season and significantly more moisture than control groups during wet tests. Overall, the team observed that this technology produces better quality berries and expands the viable harvest window, allowing farmers to pick fruit in the morning or evening even when dew is present.

An Update from the Maine Wild Blueberry Growers’ Association

While the final steps are close at hand to formally establish the Maine Wild Blueberry Growers’ Association Ron Howard expects it will be a couple more months before it is completely established. One of the objectives of the Association will be to help identify opportunities for growers to work together to achieve cost savings. Our recent sharing of information about growers participating in a group buy of the new totes that have been found to be preferred for fresh pack operations is one example. In the next few weeks we will be organizing a cardboard box group buy.

If you would like to be added to the Association email list, send a message to Ron at mainewbga@gmail.com.

Sincerely,

Lily 

Dr. Lily Calderwood
Extension Wild Blueberry Specialist
Associate Professor of Horticulture