Field studies were conducted near Painter, VA, in 1995 and 1996 to investigate the effects of herbicides and cultivation on weed control, yield, and net returns in potato. Potato injury from herbicides and/or cultivation was not observed in 1995 and was less than 12% in 1996. Metribuzin plus metolachlor preemergence controlled yellow nutsedge by at least 81% regardless of the number of cultivations in 1995 and 1996. Yellow nutsedge control with metribuzin plus rimsulfuron postemergence (POST) plus three cultivations was as high as 70% in 1995 and 88% in 1996. Metribuzin plus rimsulfuron POST controlled common lambsquarters by at least 95% and common ragweed by at least 83% regardless of the number of cultivations in 1995 and 1996. A-size tuber production and net returns from potato receiving herbicides were not improved with two or three cultivations in 1995 or 1996. However, when averaged over all weed control systems (herbicide and cultivation-only systems) multiple cultivations significantly increased control of all weed species, A-size tuber production, and net returns.
Nomenclature: Metolachlor; metribuzin; rimsulfuron; common lambsquarters, Chenopodium album L. #3 CHEAL; common ragweed, Ambrosia artemisiifolia L. # AMBEL; potato, Solanum tuberosum L., ‘Superior’; yellow nutsedge, Cyperus esculentus L. # CYPES.
Additional index word: A-size potato.
Abbreviations: POST, postemergence; PRE, preemergence; WAP, weeks after planting; WAT, weeks after treatment.