Submitted to: Potato Progress
Publication Type: Trade Journal
Publication Acceptance Date: 10/6/2016
Publication Date: 10/7/2016
Citation: Horton, D.R., Thinakaran, J., Cooper, W.R., Munyaneza, J.E., Wohleb, C., Waters, T., Snyder, W., Fu, Z., Crowder, D., Jensen, A. 2016. Matrimony vine and potato psyllid in the Pacific Northwest: a worrisome marriage?. Potato Progress. 16:14.

Interpretive Summary: Zebra chip, an economically important disease of potato in the United States, is vectored by the potato psyllid. Researchers at USDA-ARS Wapato in Washington, in collaboration with scientists from Washington State University and the potato industry in the Pacific Northwest, have determined that matrimony vine, a perennial plant related to potato, hosts potato psyllid at all times of year. It was discovered that psyllid numbers drop substantially on matrimony vine in mid-summer, at the same time that potato psyllid begins to arrive in potato fields, and this has prompted researchers to suggest that psyllids are arriving in potato following dispersal from matrimony vine. This information will help potato growers minimize damage due to zebra chip by allowing them to better predict when and in what potato fields the psyllid is likely to first arrive during the growing season.

Technical Abstract: Managing zebra chip disease in the potato growing regions of Washington, Oregon, and Idaho is complicated by confusion about the source of the insect vector (potato psyllid) as it colonizes potato fields in these growing regions. Not knowing where the psyllid is before arriving in Washington potato fields makes it difficult for growers to anticipate when (seasonally) the insect will be arriving in fields. We discuss the possible role of matrimony vine (Lycium species) as sources of potato psyllid arriving in potato in early June. Two years of monitoring matrimony vine at various locations in Washington State led to the discovery that these plants host potato psyllid at all times of year, but that psyllid counts drop drastically in mid-summer accompanying summer leaf drop. Potato psyllids begin to arrive in potato fields at the same time matrimony vine is entering this summer dormancy, suggesting that summer leaf drop by the host plant prompts dispersal by psyllids into potato fields. A simple visual model is developed to show this hypothetical interaction between potato psyllid and its matrimony vine and potato host plants.