Abstract: Volunteer potato plants are difficult to control in rotational crops, and they 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 (POST) herbicide applications in the conventional system. Final potato tuber weight was not different between tillage levels in 1994 or 1995. Herbicide treatments reduced potato tuber weight 64 to 96% in no-till corn and 85 to 99% in conventionally tilled corn compared to nontreated checks. Atrazine applied preemergence at 1.1 kg ai/ha followed by dicamba plus 2,4-D applied POST at 0.28 plus 1.1 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 eight-leaf stage to potato grown without a corn crop, and followed by cultivation 10 d later, reduced the number of potato tubers produced 79 to 95% compared to nontreated potato.

Nomenclature: Atrazine; cyanazine; 2,4-D, dicamba, dimethylamine salt; fluroxypyr; glyphosate, nicosulfuron; primisulfuron; triclopyr, triethylamine salt; corn, Zea mays L ‘Pioneer 3394’; potato, Solanum tuberosum L. ‘Russet Burbank.’

Additional index words: No-till, reservoir tillage (dammer diking).

Abbreviations: DAT, days after treatment; EPOST, early postemergence; LPOST, late postemergence; PRE, preemergence; POST, postemergence; WAT, weeks after treatment.