The California Almond Harvest
Good harvesting techniques and post-harvest handling are keys to achieving maximum yield of high-quality California Almonds, which determines marketability and profit.
Almonds should be harvested as soon as possible after they have matured to avoid quality loss and to minimize exposure to navel orangeworm and subsequent contamination with aflatoxin.
A successful harvest begins with a clean, dry orchard floor. Harvest should begin as soon as the crop is mature to avoid exposure to a third flight of navel orangeworm.
After the crop is shaken to the ground, the nuts are raked into windrows and allowed to dry, ideally to a hull moisture content that does not exceed 12%, or a kernel moisture content that does not exceed 6%, which can take anywhere from a few days up to two weeks. A harvest sample taken after shaking and before the crop is windrowed will provide a progress report of that season’s IPM program, and will indicate what pests are in the orchard to help determine the management activities for the next year.
Pickup machines sweep the windrows into carts or trailers for transportation to the huller/sheller. With the large crops of recent years, it has become more and more common for almonds to be stockpiled, either in the orchard or at the huller/shellers. To avoid insect damage, stockpiles should be monitored and fumigated as necessary. Stockpiled almonds are also susceptible to growth of the fungi that cause the contaminant aflatoxin, and should be monitored for moisture and temperature and managed to prevent moisture buildup.
Hulled and shelled nuts are then transported to processing facilities, where they are stored pending further processing. Periodic fumigation may be necessary to control insects in stored almonds, depending on the duration of storage and storage conditions.