Ricky Clark, Cody Copp, Logan Bennett, Patricia Skinkis, Inga Zasada, and Alexander Levin*
*Oregon State University, Southern Oregon Research and Extension Center, 569 Hanley Rd, Central Point, OR, 97502 (alexander.levin@oregonstate.edu)

Winegrapes are an excellent host for numerous plant-parasitic nematodes and previous work has characterized nematode presence in Oregon vineyards. However, little work has been done to catalog the diversity of nematode species found in OR vineyards since the mid-1990s. The OR winegrape industry has expanded significantly since then, growing to nearly 45,000 acres. The cultivation of winegrapes now occurs on land with diverse usage histories ranging from forest and native pasture to former fruit and nut orchards. Therefore, this three-year survey was designed to identify the distribution and abundance of plant-parasitic nematodes across OR vineyards. The survey was started in the fall of 2023 and will continue through the spring of 2025 with the intention of capturing nematode diversity throughout the diverse viticultural geography of the state across three years. Samples will be taken from the predominant winegrowing areas of the state, including the North and South Willamette, Colombia, Rogue, and Umpqua regions. Fall 2023 samples were collected from 43 vineyard blocks across the state, distributed relative to planted acreage. Plant-parasitic nematodes were identified in 79% of surveyed vineyards blocks and in all five sampled regions of the state. Xiphinema spp. were identified in 51% of sampled blocks and in all five regions. Samples from the Colombia region yielded high abundance of Meloidogyne spp., due to the sandy soils. Samples from the Rogue region exhibited a high abundance of Mesocriconema spp., as they were present in 75% of vineyard blocks surveyed. This project aims to update and improve upon the previous statewide nematode survey from the mid-90s to provide better baseline information to the OR wine industry. The baseline data will benefit the industry by providing guidance for future studies on vineyard health and productivity, rootstock selection, and management of nematodes.

Funding Support: USDA-ARS Northwest Center for Small Fruits Research