Marina J. Gutierrez
Graduate Student
Cal Poly Strawberry Center
San Luis Obispo, California, United States
Shashika S. Hewavitharana, Plant pathology program leader & assistant professor
Associate Professor
Cal Poly Strawberry Center/Plant Sciences Department, California Polytechnic State University (Cal Poly), San Luis Obispo, CA
San Luis Obispo, California, United States
Gerald J. Holmes, Cal Poly Strawberry Center Director
Director
Cal Poly Strawberry Center
San Luis Obispo, California, United States
Yiming Feng
Extension Specialist
Virginia Seafood Agricultural Research & Extension Center, Virginia Polytechnic Institute & State University
Hampton, Virginia, United States
Sean Horner
Graduate Student
Virginia Seafood Agricultural Research & Extension Center, Virginia Polytechnic Institute & State University
Hampton, Virginia, United States
Lihong Yang
Doctoral Student
Virginia Seafood Agricultural Research & Extension Center, Virginia Polytechnic Institute & State University
Hampton, Virginia, United States
Lauren C. Garner
Professor
Plant Sciences Department, California Polytechnic State University
San Luis Obispo, California, United States
Botrytis fruit rot (BFR), caused by Botrytis cinerea, and powdery mildew (PM), caused by Podosphaera aphanis, are common and economically significant strawberry diseases. The use of essential oils as biological controls could limit crop loss, reduce fungicide use, and slow resistance accumulation to major fungicide classes. However, low solubility and high volatility present challenges. Nano-encapsulation of essential oil offers a solution by enhancing dispersibility and retention of volatile compounds, providing longer residual protection and reducing the product amount needed to inhibit pathogen growth. Using citrus byproducts as an oil source, the efficacy of essential oils for control of B. cinerea and P. aphanis will be evaluated. ‘Clemenules’ mandarins, ‘Lisbon’ lemons and ‘Washington’ navel oranges were harvested from groves at Cal Poly State University San Luis Obispo. Essential oils from each species have been extracted and will be characterized to develop a nano-encapsulation technique. Once the nano-emulsion is finalized, an in vitro assay, detached fruit bioassay, and field trial will be conducted for BFR. For PM, a detached leaflet bioassay and greenhouse trial will be conducted. Preliminary data evaluating the efficacy of a commercially available orange oil against B. cinerea in an in vitro assay revealed that at concentrations of 10, 100 and 200 µl/ml, inhibitory effects on B. cinerea growth were 18, 57 and 65%, respectively. Nano-encapsulated formulations have the potential to increase efficacy, further enhancing this sustainable approach to disease control.