Tuesday, August 8, 2017

Kernel development: 8 Aug 17

   This time of year I like to monitor pecan kernel development pretty closely for two reasons. The first is to determine when nuts reach the full water stage which is the optimum time for shaking trees to reduce an excessive nut crop. Then when kernels transition into the dough stage, I'll know when pecan weevils will begin laying eggs inside the nut.

   Today, I cut open the nuts of several well known pecan cultivars and a few new and emerging cultivars (photos at right and below). Let see how their kernels are developing.
   The first set of cultivars I placed in a photo together are the progeny of Major.
Kanza, Lakota, and Hark all dripped out liquid endosperm when cut open but the kernels inside have not yet reach the full water stage.

    In the second photo, I placed three early ripening cultivars to see if one of these pecans had reached the full water stage. Osage and Goosepond are close but only Mullahy has reached what I call the water stage. Notice how the kernel halves of Mullahy have grown almost all the way to the base of the shell.
     The next photo shows a collection of USDA cultivars. I've arranged the nuts in this photo by ripening date--Pawnee being the earliest to ripen and Mohawk being the latest. I was surprised to see that Pawnee was still only three quarters of the way to full water stage. Kanza and Lakota were both ahead of Pawnee this year. I guess that why I still need to check kernel development every year.

   The final photo show a couple of old time cultivars (Giles and Posey) versus two recently discovered cultivars (SWB617 and Waccamaw). SWB617 is a seedling of Giles but it ripens way before it's parent. As you can see SWB617 has nearly achieved full water stage while Giles is still at one half water. Waccamaw is a large nut similar to Posey and their stage of kernel development is close to the same. I'll be interested to see what Waccamaw does in the future.