Over the past week I've noticed a major change in our pecan grove--the trees have taken on their fall colors (photo at right). Pecan trees never develop flashy fall color but, as the trees prepare for winter dormancy, leaves will yellow then turn quickly to brown before falling from the tree.
The trees pictured above are grafted to the Gardner cultivar. I walked up to the nearest tree to check on the condition of the nut crop. Even though Gardner nuts has been shuck split for about a month now, the shucks were still green, almost completely covering the nut inside. Sure I could shake the tree at this stage, but that would force me into dealing with green shucks on the cleaning table and a bin full of wet nuts.
With green shucks still covering the shell, pecans don't dry well. I harvested a couple of nuts and pulled back the shuck to reveal free moisture on the outside of the shell (Photo at left). A quick taste of the kernels inside these damp shells revealed that the nut meat was rubbery and "green" tasting (both indications of high moisture content).
Harvesting pecans with high moisture content runs the same risks a harvesting grain before fully dry. Wet nuts can mold, heat up, and destroy pecan kernel quality. If pecans are harvested with high moisture content, they must be dried using a forced air system to remove kernel moisture as fast a possible.
At the Pecan Experiment Field, we don't have the time or resources to dry large quantities of early-harvested pecans. So we wait for nature to dry the crop. What usually happens is that a killing freeze in early November will kill green shucks. This allows the shucks to finally dry, pull back away from the nuts, and the nuts will dry on the tree. So for now, we'll wait.
