Pests & Diseases
Navel orangeworm is a major insect pest of California almonds, walnuts, and pistachios. Worms bore holes and feed on nutmeat, causing food safety issues. Black pecan aphids attack foliage, causing premature leaf drop, poor nut quality, and reduced bloom in subsequent seasons.
Codling moths attack and feed on walnuts, damaging the kernel. Leaffooted plant bugs can cause severe damage to almond orchards, leading to malformed nuts, internal damage, and stained shells.
Depending on the variety and location, tree nuts can be vulnerable to numerous diseases, including eastern filbert blight, lethal to hazelnuts; botrytis blossom and shoot blight, which can cause tender shoots in pistachios to wither and die; and bacterial spot, also called bacterial leaf spot or shot hole, which affects almond leaves, twigs, fruit, and flowers. All of the above can cause serious damage if not controlled.
Storage & Packaging
Typically, lower temperatures will result in longer storage: in-shell pecans stored at 70°F can keep for up to 4 months, but can last up to 18 months at 32 to 36°F. When stored at 0°F, storage can extend to 5 or more years. Shelled nuts do not last as long as in-shell nuts due to moisture absorption.
References: Almond Board of California, American Pistachio Growers, California Walnut Board, National Pecan Growers Council, University of California Division of Agriculture & Natural Resources, University of Florida/IFAS Extension, University of Hawaii, USDA.
GRADES & GOOD ARRIVAL
There are many U.S. grades for tree nuts: U.S. Fancy, U.S. Extra No. 1, U.S. No. 1, U.S. No. 1 Pieces, U.S. No. 1 Halves, U.S. No. 1 Halves and Pieces, U.S. Select, U.S. Artificially Opened, U.S. Non-Split, U.S. Commercial Halves, U.S. Commercial Halves and Pieces, U.S. Commercial Pieces, U.S. No. 2, U.S. No. 3, U.S. Commercial, U.S. Select Sheller Run, U.S. Standard Sheller Run.
Quality defects include badly misshapen nuts, insect injury, physical damage, rancid product, foreign material, mold, discoloration, perforated shells, etc.
There are no good arrival guidelines specific to tree nuts (individually or collectively).