|HOWLAND, AMANDA - University Of Missouri|
|EAST, K - Washington State University|
|MOYER, MICHELLE - Washington State University|
Submitted to: American Journal of Enology and Viticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2018
Publication Date: 1/15/2019
Citation: Zasada, I.A., Howland, A.D., Peetz, A.B., East, K., Moyer, M.M. 2019. Vitis spp. rootstocks are poor hosts for Meloidogyne hapla, a nematode commonly found in Washington winegrape vineyards. American Journal of Enology and Viticulture. 70(1):1-8. https://doi.org/10.5344/ajev.2018.18027.
Interpretive Summary: Plant-parasitic nematodes, microscopic roundworms that feed on the roots of plants, are production-limiting pests in most wine grape producing regions of the world. In Washington state, the second largest wine grape producer in the U.S., plant-parasitic nematodes are found widespread in vineyards. However, wine grape growers do not have adequate methods to manage nematodes in this region. This research was conducted to identify planting material that that does not allow the root-knot nematode to increase in population size. The results from greenhouse experiments indicate that there are several types of planting material that do not allow the nematode to increase its population size. This research will be used by wine grape growers to select planting material for new vineyard sites that will keep root-knot nematode populations low and therefore reduce the impact of this nematode on vine productivity.
Technical Abstract: The majority of wine grape (Vitis vinifera) vineyards in Washington are planted with own-rooted grapevines, as opposed to grapevines grafted onto rootstock varieties. The plant-parasitic nematode Meloidogyne hapla (common name: northern root-knot nematode) is commonly found in Washington wine grape vineyard, and own-rooted grapevines are susceptible to this nematode. To use rootstocks for M. hapla management or for other horticultural characteristics in Washington, their host status for M. hapla should be defined. In greenhouse experiments, 10 commercially-available rootstock varieties were evaluated for their M. hapla host status. Additionally, the reproductive potential of different M. hapla populations, and another root-knot nematode, M. chitwoodi, on rootstock varieties and own-rooted Chardonnay was evaluated. The rootstocks Salt Creek, Freedom, Harmony, St. George, Riparia Gloire, 101-14, 3309C, 110R, 420A, and Matador were poor hosts for four populations of M. hapla collected from Washington and Oregon. Populations of M. hapla varied in reproductive potential and virulence on own-rooted Chardonnay. A M. hapla population collected from a V. vinifera vineyard in Paterson, WA had 33 to 78% greater reproduction than the other M. hapla populations. A M. hapla population collected from a V. vinifera vineyard in Alderdale, WA was consistently more virulent than the other M. hapla populations. Own-rooted Chardonnay and the rootstock Matador were poor hosts for M. chitwoodi. This is the first report of the host status of several grapevine rootstocks for M. hapla, the northern root-knot nematode.