Non hybridized trees produce seedling nuts, often no larger than small oak acorns, with incredibly hard shells which makes obtaining the nutmeats almost impossible. Other poor genetics can be found even in hybrid trees whose gene pool has passed on poor quality. Poor growing conditions may include a dry spring and summer that did not enable the trees to produce a good crop, especially when irrigation is not used, and in soils that have poor moisture retention to begin with. Low levels of critical soil nutrients, especially nitrogen and trace minerals/elements like zinc, iron, and manganese can substantially reduce the quality of the nuts. Insect infestations such as web worms, bud worms, and pecan weevils can also have a serious impact on the health of the tree and the nut itself. Very late frosts or freezes can damage the blooms and buds of the pecan tree, reducing the set of the nuts during or after the blooming period.
Coloration. Good pecans should have a uniform color. Some varieties, like Stuarts and Donaldsons have stripes near the bud ends, and a good definition between the stripe color (usually black), and the shells (light tan) are indicative of a good nut. Shell shape. Pecans form inside the husk as nutrients are passed through the veins in the husk, then through the still soft shell, filling out from the bud end to the tip. If dry weather, depletion of soil nutrients, or insect damage to the husk interrupts this feeding process, the nut will taper toward the tip end, meaning the nutmeat has not continued to grow completely. Sound. This may seem unusual, but pecans, when they are rattled or dropped together, make a distinctive sound. Hollow sounding pecans are likely not filled out, whereas good, full pecans will sound solid, even if just rattled together in your hands. As you gather the pecans, shake them, and crack a few suspicious sounding ones, and you will soon develop an ear for the sound of a good, full pecan. Weight. Although individual pecans weigh very little, an experienced picker, especially when picking or sorting by hand, will soon notice a distinct difference in weight of full pecans, compared to lesser quality ones.
