Pecan Bacterial Leaf Scorch

Abstract

Pecan bacterial leaf scorch (PBLS) is an important and chronic disease that affects pecan in Arizona, as well as other pecan production regions of the United States. This disease was first noticed throughout the southeastern United States in 1972 and mistakenly thought to be a fungal disease. In 2000, the disease was correctly identified as a bacterial disease known as PBLS, impacting mostly the eastern growing region of the US. Currently, there are more than 25,000 acres, of which 14,000 is in fruit bearing age. Pecan acreage continues to grow by 2,000 acres annually. In 2015, the AZ pecan industry contributed more than $54 million dollars to the state’s economy. Pecan bacterial leaf scorch was first detected in 2015 not only in Arizona, but also in California, New Mexico, and Texas. PBLS is a primary concern for pecan trees under stressful conditions including nutritional, physiological, and environmental stress. PBLS is a rapidly emerging disease to Arizona pecan industry and this document is designed to help pecan growers answer commonly asked questions about PBLS.