Wednesday, November 15, 2017

Harvesting Pawnee pecans

    We've been working our way through harvest picking up nuts in a various research plots. Last week we harvested Pawnee (photo at right) and I was pleased to see that summer shaking really paid off in terms of nut quality this Fall. This year's Pawnee nuts are some of the best we've every raised.
    Pawnee has become a popular cultivar in northern pecan states because it ripens early and it produces large, thin-shelled nuts. With a good scab control program and crop load management, Pawnee can be a reliable income producer.  
     However, we have experienced one problem in growing Pawnee that is rarely if ever mentioned--Pawnee nuts do not fair so well when harvested mechanically.


    The shells of Pawnee nuts are so thin that they often get cracked during harvest operations. I collected a few nuts from the cleaning table to show you what I mean. The majority of Pawnee nuts come through harvest fully intact (first 3 nuts in top row, photo above). Many nuts get cracked but the shell still covers the nut meat (top right nut, above). However, about 5% of the Pawnee nuts that come across the inspection table are cracked open, exposing the nut meat inside (nuts in bottom row, above).  Sell-able pecans must have intact shells to protect nut meats from contamination. When we sort our Pawnee nuts, any nuts with exposed kernel are thrown off the table.
   Although consumers prefer nuts with paper-thin shells, they also demand a clean wholesome product. I have come to the realization that pecan cultivars that produce nuts with greater than 56% kernel will suffer significant nut losses due to mechanical harvest using current equipment.  This observation is something I'll keep in mind when evaluating the nuts produced in our breeding program.