Pecan cultivars that split shucks in late September

Osage, 28 Sept. 2017

   I spent a sunny afternoon looking over our pecan crop and photographing pecan cultivars that have split open their shucks since last week. I found 12 cultivars fully ripe (photo as right and below).
    As you look over the photos you can spot the cultivars that are susceptible to pecan scab. The 12 pecan cultivars that ripened this week can be broken down into three categories when it comes to pecan scab; resistant, susceptible but clean, and susceptible with scab lesions. The "susceptible but clean" cultivars are mildly susceptible to scab allowing our fungicide spray program to completely control the disease. The "susceptible with scab lesions" have a greater degree of susceptibility to scab infection and our spray program did not provide perfect control. Below is a list of the cultivars that ripened this week divided into the three scab susceptibility categories.

Resistant:   Norton, Osage, Shepherd

Susceptible but clean:  City Park, James, Posey, Surecrop, USDA 75-8-5

Susceptible with scab lesions: Canton, Colby, Witte, USDA 64-11-17

Norton, 28 Sept. 2017

James, 28 Sept. 2017

Colby, 28 Sept. 2017

 

City Park, 28 Sept. 2017

Canton, 28 Sept. 2017

Posey, 28 Sept. 2017

Shepherd, 28 Oct. 2017

 

Surecrop, 28 Sept. 2017

Witte, 28 Sept. 2017

USDA 64-11-17, 28 Sept. 2017

USDA 75-8-5, 28 Sept. 2017

More early ripening pecans split shuck

KT143 (Pawnee x Major)

    Yesterday, I spent the day in a hydraulic lift evaluating the nuts of pecan trees in our pecan breeding trial. I found 14 pecan hybrids that had split shuck since my last trip thru the orchard (Sept. 20)  As I traveled down the row of pecan crosses, I came to tree KT143. This tree has a special place in the history of our pecan breeding project. KT143 was the very first tree in the planting to start bearing pecans and has produced a crop every year since. KT143 is the result of a cross between Pawnee and Major. The nut appears to be scab resistant and the shucks opened before either parent this year (photo above).

    Of course, its whats inside the shell that counts when evaluating pecan hybrids. My records from previous years tell me that KT143 averages 7.52 g/nut and produces 54.8% kernel. From a practical point of view, I measured the 2017 crop and found it would drop out of a pecan sizer as a number 15 (15/16 inch).  As you can see from the photo above, the kernels have wide dorsal grooves meaning the kernels will drop free of all shell fragments when cracked. We currently have this clone under advanced testing in a new planting at the Pecan Experiment Field.

Early ripening pecan cultivars split shucks

   Yesterday, I found that the earliest ripening cross in our pecan breeding plot had split shuck. So today, I inspected all of our pecan cultivar trials at the Pecan Experiment Field to discover which early ripening pecans had split shucks.

Henning, 21 Sept. 2017

   I found three pecan cultivars with split shucks (photos at right and below). Henning and Mullahy are northern pecan cultivars first discovered as native trees. SWB617 is a chance Giles seedling we have at the research station. I expected Warren 346 be be ripe at this time but our trees of this cultivar do not have a nut crop this year.

Mullahy, 21 Sept. 2017

SWB617, 21 Sept. 2017

First pecan to shuck-split

   I spent some time today looking at trees in our pecan breeding plot. I was especially interested to see if our earliest ripening hybrid had split their shucks yet. Using our hydraulic lift, I climbed up into the canopy of the tree to find limbs loaded with fully ripen pecans (photo at right). This is a tree labeled as KT337, a cross between Pawnee and Greenriver. So far, this tree has demonstrated good scab resistance and is bearing annually.

   The nuts of KT337 are small in comparison to many modern pecan cultivars but are large enough to produce very attractive kernels (photo above).  The few nuts I pulled from the tree averaged 13/16 inch in diameter (21mm) and were 1.5 inches long (38mm).  The kernel was well packed inside the shell and the dorsal grooves were wide and "v" shaped (indicating the nut meat will fall free from all shell and packing material). I'll be keeping my eye on this one.

    To give you a better idea about nut size, I collected a few Pawnee nuts and peeled the nuts out of the shuck (Pawnee has not split shuck yet that's why the shell color is white). The photo above gives you a good visual reference as to the size of KT337.  The nuts are obviously smaller than Pawnee but not  unacceptably small.