Submitted to: Potato Progress
Publication Type: Trade Journal
Publication Acceptance Date: 8/6/2008
Publication Date: 8/10/2008
Citation: Horton, D.R. 2008. No Effects of an Autumn Mustard Crop on Wireworm Densities or Damaage to Potatoes in the Following Growing Season. Potato Progress. 8:1-4. Interpretive Summary: Wireworms damage potato tubers and must be controlled by pesticides. A scientist with USDA-ARS, Yakima Agricultural Research Laboratory, Wapato, WA studied the effects of a mustard crop grown in the season preceding a potato crop to determine whether the mustard led to lowered rates of tuber damage from wireworms and increased tuber yield. Results showed that the mustard had no effect on wireworm damage to tubers, but did result in a slight drop in tuber yield. These results indicate that potato growers would receive no benefits associated with improved wireworm control if they were to plant a mustard crop in the season preceding their potato crop, and could suffer a slight drop in yield.
Technical Abstract: Chemicals produced by mustard (Brassica) crops as they are tilled into the soil have been shown especially in laboratory trials to suppress soil-dwelling organisms, including fungal pathogens, nematodes, and some insect pests of crops. Here, I tested in the field whether an autumn mustard crop grown between a wheat-potato rotation led to reductions in numbers of Pacific coast wireworm and damage by wireworms to tubers. Mustard was planted in late summer and tilled into the soil in October preceding a potato crop the following season. The mustard had no effects on spring densities of Pacific coast wireworm or subsequent damage to harvested tubers caused by wireworms. Damage rates were higher for large tubers than small tubers, in both mustard and control plots. There was a slight but statistically significant drop in tuber yield associated with the mustard cover crop.