Sweetpotato clone tolerance to weed interference

Field experiments were conducted to assess how sweetpotato [Ipomoea batatas (L.) Lam.] clones interfere with weeds and how clones tolerate weed interf erence. Eleven clones with architecturally different canopies were evaluate d for yield, canopy surface area and dry mass, weed dry mass, and light int erception at ground level. A 2-fold difference in ground area covered by ca nopy surface area was observed among the eleven clones 42 days after planti ng, and a 3-fold difference in canopy dry mass at harvest. Yields were redu ced from 14% to 68% by weed interference. The yields of high-yielding clone s, 'Beauregard', 'Excel', L87-125,'Regal', 'Centennial', and W-274, were re duced to a significantly greater extent by weeds than were yields of the ot her five clones. No differences were observed between clones for weed suppr ession as measured by weed dry mass at harvest and ground light interceptio n. Short-internode and long-internode clones had similar competitive abilit ies. Yield of high-yielding clones was impacted more by weed interference t han was that of low-yielding clones.