USDA ARS
The glassy-winged sharpshooter, most often attributed to Pierce’s disease in vineyards, can also be a culprit behind bacterial leaf scorch in pecans.
Symptoms become apparent in late spring.
Pecan bacterial leaf scorch has been around for about five years now in California, Arizona, Texas, and New Mexico orchards.
First noticed in the southeastern United States and mistakenly thought to be a fungal disease, it was correctly identified as a bacterial disease that quickly picked up the moniker, PBLS.
The scorch, with symptoms of browning and necrosis of terminal leaflets, becomes apparent in late spring and is a primary concern for pecan trees under stressful conditions, be it environmental, nutritional, or physiological.