As almond yields increase, growers may find themselves with more harvested crop than processors can handle. Proper stockpiling techniques can help maintain quality during the wait.
David Doll, pomology farm advisor for the University of California Cooperative Extension of Merced County, says that nearly all of the crop is harvested within 6-8 weeks, causing backups. Doll maintains a blog called “The Almond Doctor” through University of California Cooperative and shared his thoughts in a post titled Stockpiling Almonds During Harvest.
“The industry just has a lot of production capacity and a limited ability to process at a given time,” he says.
Doll says growers who stockpile should follow these guidelines:
- Fumigate the pile for navel orangeworm. The pest can still pose a problem even after harvest. “It can continue to reproduce and feed on crop if it’s piled on the ground,” Doll says. Fumigation will kill the navel orangeworm eggs as well.
- Harvest when moisture content of in-hull almonds is at or below 9%. The almond hulls should snap when bent. This reduces the chances of harmful molds such as aflatoxin. Proper drainage around the pile is key.
- Moisture content of the pile should stay below 14%. Higher moisture levels and pile temperatures above 120 degrees can increase chances for molds or spontaneous combustion.
- Use white-on-black tarps to cover the piles. Studies have shown that these tarps stabilize the pile temperature, keeping it cooler during the hottest parts of the day and warmer during the coolest parts of the night. Temperature fluctuations can contribute to condensation. Also, remove tarps during the day to allow moisture to evaporate.
- Situate the pile length-wise from north to south, reducing the amount of the pile exposed to the sun throughout the day. That will help reduce condensation.
“It’s a lot of work,” Doll says. “There’s no doubt that it takes a lot of time, but it’s important to do it to reduce insect infestations and reduce aflatoxin and to maintain a high-quality product.”