Author
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Boydston, Rick |
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Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/1/2001 Publication Date: 9/1/2001 Citation: BOYDSTON, R.A. VOLUNTEER POTATO (SOLANUM TUBEROSUM) CONTROL WITH HERBICIDES AND CULTIVATION IN FIELD CORN (ZEA MAYS). WEED TECHNOLOGY, 15:461-466. 2001. Interpretive Summary: Over 68,000 ha of potatoes are grown annually in the Columbia Basin. Between 106,000 to 460,000 tubers per ha are left in the soil following a typical commercial potato harvest. Winter soil temperatures in the Columbia Basin region of Washington State and Oregon and certain maritime regions of Europe are often not cold enough to adequately kill tubers left in the soil lafter potato harvest. As a result, potato shoots can emerge in the ensuing crop from over wintering tubers. Volunteer potatoes are difficult to control in rotational crops and can harbor harmful diseases, nematodes, and insects that harm potato crops. When volunteer potatoes are allowed to persist in the rotational crops many of the positive effects of crop rotation are lost. Corn is a common rotational crop with potatoes in the Columbia Basin and several herbicides and tillage regimes were tested to determine the level of volunteer potato control and corn yield. In a separate experiment, several postemergence applied herbicides combine with and without cultivation were tested for potato control. This research identified several practices that growers can use to reduce volunteer potatoes in field corn. In the field corn study, atrazine applied preemergence followed by dicamba plus 2,4-D applied postemergence provided the most consistent control of volunteer potatoes with maximum reduction in final potato tuber weight and numbers. This treatment combined with cultivation reduced final potato tuber weight in corn by 98% or more. Cultivation about 10 days after postemergence applied herbicides improved the control of volunteer potatoes, and most importantly, reduced the number of tubers that remained in the field. Technical Abstract: Volunteer potatoes are difficult to control in rotational crops and harbor harmful diseases, nematodes, and insects. Five herbicide treatments were evaluated for control of volunteer potato in field corn grown under no-till and conventional tillage in 1994 and 1995. In mid June, potato control was greater in conventionally tilled corn than no-till corn primarily due to the reservoir tillage that followed postemergence herbicide applications i the conventional system. Potato final tuber weight was not different between tillage levels in 1994 or 1995. Herbicide treatments reduced potato tuber weight by 64 to 96% in no-till corn and by 85 to 99% in conventionally tilled corn compared to nontreated checks. Atrazine applied preemergence at 1.1 kg ac/ha followed by 2,4-D plus dicamba applied postemergence at 1.1 plus 0.28 kg ae/ha, respectively, reduced potato tuber weight greater than 95% in both years and both tillage systems. Corn yield was not affected by tillage level or herbicide treatments in 1994 or 1995 and averaged 10.5 MT/ha in 1994 and 15.1 MT/ha in 1995. In a separate experiment, glyphosate, dicamba plus 2,4-D, or fluroxypyr applied at the 8- leaf stage to potatoes grown without a corn crop, and followed by cultivation 10 days later, all reduced the number of potato tubers produced by 79 to 95% compared to nontreated potatoes. |
