If you thought yesterday’s holiday rounded out our food plant topics, loosen your belt buckles to make room for dessert. Today we are talking about pecans. Sometimes candied pecans accompany vegetables and salads, but they are truly stars in desserts from pies to divinity to fruit cake to pralines. I’m sure many of you (over)indulged in these confections yesterday, but how much do you know about the trees behind these treats?
Carya illinoinensis is native to the southern portion of North America. Pecans were wild-harvested in Colonial days and some were likely featured in the first Thanksgiving. Today, pecans are commercially cultivated and the U.S. produces the overwhelming majority (80 – 95%) of the world’s pecans. The top pecan-producing states are Georgia and Texas. Judging from the number of pecans I have gathered from the trees in our backyard this year, 2013 is shaping up to be quite a productive pecan year. A decent amount of rain throughout the summer and no hurricanes to blow off immature nuts from the trees in August/September are contributing factors.
For the record, pecans are not nuts, botanically speaking, but drupes. True nuts (acorns, chestnuts) have shells that enclose both their fruit and seeds. In the case of drupes, the fleshy fruit encloses a thin-shelled pit that encloses the seed. Other drupes are apricots and peaches, but we eat their fruit. In the case of drupes like almonds, walnuts and pecans, we eat the seed instead of the fruit.
Here’s another lesson in plant biology for which pecan trees provide an excellent example. Sure, there are many different pecan varieties to choose from when it comes to starting your home orchard, but like apple varieties, pecans are not self-compatible when it comes to pollinating themselves. However, the underlying reason is a little different. Pecan trees do not have perfect flowers that contain both the male and female parts. Instead, they separate male (staminate or catkin) flowers and female (pistillate or nutlet) flowers. On the tree of a given cultivar the male flowers mature at a different time than the female flowers, which means that the pollen from one tree is generally not present at the time the nutlets are ready. The scientific term for this temporal separation of the male and female reproductive organs is called dichogamy. Cultivars in which there is no overlap of mature male and female flowers have complete dichogamy. (Even if there is incomplete dichogamy with some overlap, pollination is poor and doesn’t result in pecan production.) Here is a list of common pecan varieties with their catkin and nutlet maturation schedules. So make sure you pick at least two varieties with compatible pollination schedules.
As you can see there are lots of pecan cultivars to choose from. Because of the self-incompatibility problem mentioned above, growing pecan trees from nuts is guaranteed to give you a genetic surprise (probably not a good one) in about a decade when it starts producing its own nuts. For this reason, pecan cultivars are propagated by grafting pieces of desirable varieties onto receptive rootstocks. The first grafted variety from 1846 is credited to a slave at Oak Alley Plantation known only as ‘Antoine’ who successfully grafted sixteen trees for the plantation. This variety was later named Centennial. Since then, many favorite varieties have been successfully grafted and named for their area of origin, often commemorating the Native American tribes with which they were associated.
Not only does Louisiana have a long history of growing and harvesting pecans, but we also have examples of longstanding pecan processing companies. Bergeron Pecans in Pointe Coupee Parish has been in business for more than 100 years. They shell about 5 million pounds of pecans annually at their facility on Hwy 1 across from False River. Depending on your location, you may find bags of shelled Bergeron pecans in your local grocery store, but don’t bother looking for them on the internet. They do not exist in cyberspace. If you find yourself in New Roads, LA with a fever for local pecans, stop by with cash or checks only because Bergeron Pecans is one family business that stands on tradition.
So as you are polishing off the last of your pecan pie this day-after-Thanksgiving, savor the history and unique biology of this native crop.