Submitted to: Potato Country USA
Publication Type: Popular Publication
Publication Acceptance Date: 2/1/2006
Publication Date: 6/1/2006
Citation: Boydston, R.A. 2006. Volunteer potato management for 2006. Potato Country USA. Pp 10-11.
Technical Abstract: Potato tubers left in the ground following a potato harvest often over winter in regions with mild winter temperatures resulting in a serious and difficult to manage weed problem in the ensuing crop rotation. Potatoes normally are killed when they reach temperatures below 28° F. Many potato tubers left in the soil after the 2005 fall harvest were killed by cold soil temperatures throughout the Columbia Basin. Soil temperatures reached a minimum on Dec. 19, 2005 throughout the Columbia Basin region. Minimum soil temperatures at the 8 inch depth recorded near Quincy and Royal City, WA reached 27.8 F and 26 F, respectively. However, minimum soil temperatures in December recorded at 4 and 8 in. at Prosser, Hermiston, and Odessa did not drop below 29 F. Minimum soil temperatures in December recorded 8 in. deep near Othello and Paterson did not drop below 31 F and 29 F, respectively. Minimum soil temperatures at the ARS Paterson research farm in December were 26.6 F at 4 in. deep and 29.1 F at 7 in. deep, which has the potential to eliminate the majority of the tubers left in the soil. Differences in soil temperatures throughout the region are likely due to differences in air temperatures, snow cover, soil moisture, aspect, and amount of crop residues left on the surface. Due to variation in soil temperatures from site to site, examination of potato fields should be done to accurately determine the extent of winter kill. We estimate more tuber mortality than occurred in 2005, but certain areas of the Columbia Basin that had snow cover during cold events, north facing slopes, and heavy crop residues may still be faced with significant volunteer potato problems in 2006. Recommendations for volunteer potato management in rotation crops are summarized.