Tuesday, August 27, 2013
Nut development: 26 August 2013
This summer, I've been following kernel development of three pecan cultivars; Osage, Kanza and Maramec (photo above). I choose these three cultivars because they represent early, mid season, and late ripening pecan cultivars. Previously, I had cut open nuts longitudinally to reveal the progress of kernel expansion from from the small heart stage to full water stage. However, with the kernel development process starting to switch over from the expansion phase to the kernel filling phase, its time to look at nut development from a new angle. At this stage, a cross sectional cut through the nut gives a clearer picture of the kernel filling process. Lets take a closer look at nuts from each of these cultivars.
After comparing the photo of Osage to the photos of Kanza and Maramec (photos below) I discovered something new about kernel expansion I hadn't seen before. Once the kernel becomes fully extended in length, the kernel continues to expand but in an outward direction. This outward expansion compacts internal packing material up against the inside of the shell. By comparing the close-up photos of Osage, Kanza, and Maramec you can easily see this process in action.
Hopefully the return of hot summer temperatures this week will help stimulate pecan crop development. Its nearly September and most cultivars are still weeks behind in terms of the normal kernel filling period. Lets hope for a long warm Fall.