A grand, old pecan tree in your yard is a wonderful anchor for the space, a good source of a large, shady patch, and of course a bountiful provider of tasty pecan nuts. But, if your tree gets struck with pecan phytophthora rot, a fungal infection, you could lose the entire harvest.
What is Pecan Shuck and Kernel Rot?
The disease is caused by a fungal species, Phytophthora cactorum. It causes rot in the fruit of the tree, turning the shuck into a mushy, rotted mess, and rendering the nuts inedible. The disease is most common after it has been wet for several days and when the temperatures remain below 87 degrees Fahrenheit (30 Celsius) during the day.
Pecan shuck and kernel rot infections usually occur in late August or early September. The rot begins at the stem end and slowly covers the entire fruit. The rotten part of the shuck is dark brown with a lighter margin. Inside the shuck, the nut will be dark and bitter tasting. The spread of the rot from one end of a fruit to the other takes about four days.
Pecan Shuck Rot Treatment and Prevention
This fungal infection is not that common and tends to occur in only sporadic outbreaks. However, when it does strike, it can ruin half or more of a tree’s crop. It’s important to provide pecan trees with the best conditions for preventing the disease and to look for signs of it in order to treat immediately.
The best prevention is to simply make sure the tree is trimmed adequately to allow for airflow between branches and around fruits.
To control pecan kernel rot in trees that already have signs of the infection, a fungicide should be used right away. If possible, apply the fungicide before the shucks split. This application may not save every nut on the tree, but it should reduce the losses. AgriTin and SuperTin are two fungicides used to treat pecan shuck rot.