Sunday, December 31, 2017

Stuart in the north

Stuart nuts at shuck-split

     Stuart is one of the oldest and most widely known pecan cultivars. The tree had its origins in a seedling orchard planted in 1874 outside of Pascagoula, Mississippi  using nuts procured from Mobile, Alabama. The tree gained local notoriety for excellent nut production. In 1893, a severe storm blew the original tree down. Fortunately, the tree re-emerged from a root sprout and the tree began bearing nuts again by 1902. 
     The first attempt to graft Stuart was largely a failure. In 1886, sixty grafts were attempted but only one grew successfully. Graft failure was all too common during the late 1800's as nurserymen used grafting techniques commonly used for fruit trees when trying to propagate pecans. However, by the early 1900's,  grafting techniques specifically developed for pecan improved success rates dramatically. From the 1920's to the 1950's Stuart quickly became the  dominant cultivar planted across the southeastern United States.
Stuart grown in SE Kansas 2017
    But how did Stuart migrate northwards? The popularity of Stuart in the south was largely driven by outstanding yields and scab resistance. Every pecan nursery began propagating Stuart and trees became so widely available that they were ultimately promoted for planting outside traditional southern pecan growing areas.  For a tree from the deep south, Stuart has excellent cold hardiness enabling Stuart trees to grow and thrive in northern pecan areas. However, it was soon discovered that northern climates do not provide a long enough growing season to properly mature nuts. Our 2017 crop of Stuart nuts contained roughly 50% stick-tights (photo above).

Poorly formed Stuart kernels
     A more common indication that Stuart is not adapted to northern climates is the incomplete development of kernel inside the shell (photo at right). Northern-grown Stuart nuts are usually fuzzy and shriveled. In addition, kernels are hollow and lack an good oily taste.
    No additions of water or fertilizer will ever alter the fact that Stuart will never make a decent kernel in northern areas. Stuart requires a longer growing season than northern pecan areas can provide for proper kernel development.
   One of the most interesting artifacts of the popularity of Stuart is the large number of Stuart seedlings that can be found growing all over the US, even in northern areas. During the Great Depression and war years (1930's and 1940's), pecans were a popular stocking stuffer for Christmas. The majority of gift basket pecans at that time were Stuart nuts and some of those nuts found their way into backyard gardens to eventually sprout into trees. Today, you can find massive 90+ year-old trees that produce a blocky shaped nut that looks a lot like a Stuart nut but is generally smaller in size. These seedlings also produce nuts that struggle to produce quality kernels in northern climates just like the mother Stuart tree.