ARS | Publication request: VOLUNTEER POTATO INTERFERENCE IN CARROT

Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 26, 2005
Publication Date: January 1, 2006
Citation: Williams, M., Boydston, R.A. 2006. Volunteer potato(Solanum tuberosum l.) interference in carrot. Weed Science. 54(1):94-99.

Interpretive Summary: Antiquated weed management systems in carrot could be improved with an understanding of the specific conditions resulting in crop yield loss and weed fecundity. Significant weed management guidelines such as economic thresholds and critical times for removal of volunteer potato, the most troublesome weed in carrot, were determined in field studies. Weed height served as a good predictor of timing weed management tactics. In addition, weed fecundity was high even before the crop suffered yield losses, underscoring the importance of targeting multiple stages of the weed life cycle. The impact of this research is being the first to document fundamental knowledge of carrot/weed ecology that could be used to guide new weed management systems in the crop.

Technical Abstract: Weed management systems in carrot are limited in part by lack of a fundamental understanding of crop/weed interactions. Irrigated field studies were conducted to quantify the effect of volunteer potato density and duration of interference on carrot yield and determine relationships among weed density, duration of weed growth, and volunteer potato tuber production. A season-long volunteer potato density of 0.06 plants m-2 produced from 0.15 to 0.23 kg tubers m-2 and resulted in 5% crop yield loss. The same level of crop loss was observed with a duration of interference of 430 GDD, whereby two volunteer potato plants m-2 produced 0.13 kg tubers m-2. Volunteer potato height at the time of weed removal predicted carrot yield loss (R2 = 0.77) and may be useful for timing of management such as handweeding. Carrot appears more tolerant to volunteer potato interference and weed suppressive than onion, another crop frequently grown in rotation with potato.