Phytophthora ramorum Nursery Survey

Phytophthora ramorum Survey Abstract Abstract (387 words) The nursery industry has a large economic impact in the state of Kentucky. In 2017, nursery greenhouse sales in Kentucky were estimated at $83 million and 2021 cash receipts were expected to total $118 million. In 2022, Kentucky had 477 licensed nurseries in the state and 924 licensed nursery dealers (data from Office of the State Entomologist); thus, it is an important industry and source of revenue. This survey will allow us to conduct a targeted survey for Phytophthora ramorum which is of concern since many nurseries in Kentucky import nursery stock from the West Coast. Detections in nurseries that ship widely throughout the United States have increased concerns that this disease could appear in other U.S. nurseries and move to susceptible species in the surrounding environment. Many states, including Kentucky, have had trace forwards in recent years. The NAPIS database shows that this disease has been found in several eastern states, many of which are close to Kentucky such as Indiana and Tennessee. Kentucky has been identified as a high risk area for Phytophthora ramorum because of the extensive oak forests within the state. This disease could also have a severe effect on an economy that depends on the revenue generated from the sale of logs and wood products. Discovery of this disease could greatly reduce the amount of oak lumber that could be exported overseas from Kentucky and, thus, have devastating economic consequences. Beginning in April/May 2023 a Nursery Inspector will visually inspect high-risk host plants for symptoms in 20 nurseries. Other personnel may assist, as needed. We will take samples from all suspicious plants (at least 5 symptomatic leaves and/or stems per sample) and submit the samples to a lab at the Pennsylvania Department of Agriculture for ELISA testing and PCR on ELISA-positive samples. Personnel will use water-baiting methods when applicable. It is anticipated that only a few of the 20 nurseries, if any, will have a water feature that will allow for this technique. It has become difficult to locate nurseries that have target plants, import stock, and have a water feature on the property. However, if such features are found, we will place field-collected Rhododendron leaves in 2 mesh bags, allow them to float in the water for 7-14 days, then submit the samples to the lab.