Why is the date of shuck split important for pecans?

Yates 68, 5 Oct. 2018

   Every fall I have spent a lot of time in a hydraulic lift inspecting pecan cultivars for their date of shuck opening. Over the years I've created a photographic record of this important event for dozens of cultivars. Just today, I noted that the cultivar Yates 68 had just split open (photo at right).
    But why is nut maturity date such an important cultivar characteristic? In northern pecan areas, only cultivars that split shuck before the average date of first fall freeze should be grown. Too often, I have come across folks in the Midwest that plant pecan cultivars advertised in flashy nurseries catalogs that never reveal that a cultivar requires a much longer growing season to ripen their nuts. It is only after 15 years of tree growth that they discover their tree only produces black stick-tights every fall. (Desirable and Western are two prime examples of cultivars not adapted to northern pecan areas).

KT255, 24 Sept. 2018

   Now that I've retired from Kansas State, my focus has shifted from taking notes on established cultivars to recording maturity dates for the trees in the breeding project. In breeding pecans for our northern area, maturity date is of prime importance. And we have found some early ripening clones. KT255 and KT307 both ripened by Sept. 24th this year. That's really not surprising since both of the trees are the results of a cross between Pawnee and Greenriver. In addition both clones have good nut size, high percent kernel and are not prone to pecan scab infections.

 Please Note.  These clones are still under test and I am not in the position to supply scions at this time. When the time comes for a new cultivar release, I'll announce it on the blog.

KT307, 24 Sept. 2018