|Williams, M - WSU-IAREC, PROSSER|
Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 9, 2003
Publication Date: April 1, 2003
Citation: BOYDSTON, R.A., WILLIAMS, M.M. EFFECT OF FUMIGATION ON VOLUNTEER POTATO (SOLANUM TUBERSOUM) TUBER VIABILITY. WEED TECHNOLOGY. 2003. 17:352:357. Interpretive Summary: Volunteer potatoes are a serious problem in crop rotations in Pacific Northwest potato growing regions. Volunteer potatoes reduce crop yields, are difficult and expensive to control, and harbor harmful pathogens and pests of potatoes. Soil fumigation has the potential to greatly reduce the number of viable volunteer potato tubers. These studies determined the effective doses and soil conditions of two fumigants; 1,3-D and metham sodium, for suppressing volunteer potatoes. Growers can use this information to more effectively time soil fumigation for optimum potato control and to refine minimum fumigant doses for optimum potato control. In general, metham sodium was more effective as soil temperature increased from 5 to 25 C indicating late summer or late spring applications may be more effective in killing potato tubers than late fall or early spring applications to cold soils. 1,3-D was more effective applied to soil at 5 and 15 C and less effective at 25 C. Both dormant and nondormant tubers were susceptible to metham sodium indicating soil fumigation soon after potato harvest may be effective.
Technical Abstract: Management of volunteer potato requires an integrated approach and soil fumigation is one tactic known to reduce population densities of certain weeds. The effect of 1,3-D and metham sodium on potato tuber viability were tested in sealed glass jars at various doses, incubation temperatures, and times of exposure. Tuber viability data were fitted to a logistic model and I90 doses (90% suppression) were calculated for each combination of temperature and time of exposure. I90 doses for 1,3-D ranged from 41 to 151 kg/ha. I90 doses for metham sodium ranged from 96 to over 480 kg/ha. With the exception of 1,3-D incubated at temperatures equal to or greater than 15°C, effectiveness of fumigants increased with temperature and time of exposure. Both nondormant and dormant tubers were injured by exposure to metham sodium. Soil fumigation with 1,3-D and metham sodium has the potential to greatly reduce the number of viable potato tubers.