Crop Moisture and Safe Stockpiling at Harvest

June 1, 2012

When sampling for moisture before sweeping, take samples across the orchard floor from trunk to the middle of the drive row and along the tree row. If sampling after sweeping, be sure to include samples from the bottom of the windrow, which will have more moisture than those taken from the top.When almond harvest swings into gear later this year, growers should be alert to the moisture content of their crop before stockpiling. Almond Board of California research focused on stockpiling and crop moisture content shows that it is important to follow key practices to avoid mold growth in piles, particularly the Aspergillus fungus and resulting aflatoxin.

Stockpiling in-hull almonds at moisture content greater than 7% leads to relative humidity (rH) within the stockpile of more than 70% — the maximum allowable rH for almond storage. Almonds should not be stockpiled if either the hull moisture content exceeds 13% or the kernel moisture content exceeds 6%. Crop moisture should be determined while the crop is on the orchard floor, either before or after sweeping. You can find specifics and strategies for sampling across the orchard floor or within windrows here.