Wednesday, October 24, 2012

Drought induced kernel defects

   I was out in the grove checking trees to determine which cultivar we were going to harvest next. As I walked under a Pawnee tree, I grabbed a few nuts and cracked them to check their kernel quality. Among the nuts I sampled, I found two that displayed common drought induced kernel defects (photo at left).
    The nut kernel at the top of the photo is covered in a fine light tan fuzz. Kernel fuzz is not a disease but simply a portion of the internal shell packing material that adheres to the surface of the kernel. Fuzzy kernels occur when insufficient soil water (i.e. drought) retards kernel expansion, preventing the kernel from tightly packing internal shell materials against the inside of the shell. Kernel fuzz is easily scraped of the kernel and does not represent a health risk if eaten.
    Another kernel defect, directly related to a shortage of water during the kernel filling process, is a shortened kernel half (nut at the bottom of the photo).  In this case, one side of the kernel didn't grow out to the end of the nutshell  because there wasn't enough water available to plump out both halves of the kernel. Short kernel halves have no impact of kernel eating quality but their occurrence reduces the total percent kernel harvested from a tree.