Tuesday, September 1, 2015

How full are pecan kernels today?

    The first day of September was a good day to check on the development of the 2015 pecan crop. I collected nuts from 14 different pecan cultivars ranging from the very early ripening Warren 346 to the late ripening (late for SE Kansas) Mohawk. I cut a nut from each cultivar in half so I could look at kernel development. Remember to click on each photo and you'll get a much larger view of the nuts in cross section.

   The photo above shows five early-ripening cultivars. Warren 346 is fully packed with kernel with all the internal packing material compressed to a orange-brown color. Shepherd and Colby nuts are largely filled with kernel but the light color of the packing material indicates that nut fill is still progressing. The Osage nut has a kernel that still has several air gaps. However the color of the packing material indicates that kernel fill is nearly complete and we might be left with a poorly filled nut meat. Faith is typically an early maturing cultivar however this nut has a long way to go in filling out the inside of the shell.

  This second group of cultivars (photo above) includes nuts that typically ripen during the first 10 days of October. Posey, Yates 68, and Surecrop kernels have filled all the space inside their shells except for a fine line down the middle of each kernel half. Major and Kanza have a lot of kernel filling to go. These two cultivars have developed only a thin layer of kernel. It looks like Major and Kanza may ripen later than normal this year.

     The final group of cultivars represent pecans that typically ripen during the last two weeks of October. Mohawk is still in the water stage with only the slightest evidence of kernel deposition. Mohawk is also the latest ripening cultivar among these four pecans. Greenriver was still mostly water but the nut has developed a visible layer of kernel just inside the seed coat. Both City Park and Lakota have a visible layer of white kernel and a prominent layer of "gel" inside. This gel layer will soon solidify and become solid white kernel. 

    A pecan enters the final stages of nut maturation when the shuck begins to separate from the shell. This process starts at the apex of a nut and works towards the base. Of all the nuts I collected on September 1st, only Warren 346 showed the first signs of shuck separation (photo at right). Over all, nut development this year seems behind schedule. This is probably due to the cooler than normal summer we have experienced in 2015. However, plentiful rainfall during August should guarantee excellent kernel quality at harvest.