Competition of Spurred Anoda, Velvetleaf, Prickly Sida, and Venice Mallow in Cotton

Abstract

Spurred anoda [Anoda cristata (L.) Schlecht.], velvetleaf (Abutilon theophrasti Medic), prickly sida (Sida spinosa L.) and Venice mallow (Hibiscus trionum L.) competition in cotton (Gossypium hirsutum L. ‘Stoneville 213′) was studied during 1973 and 1974. Cotton height was reduced by full-season competition of all species at a density greater than 32 plants/12 m of crop row. Full-season cotton competition reduced the dry matter production of velvetleaf, spurred anoda, prickly sida, and Venice mallow at weed densities less than 8, 16, 32, or 64 plants/12 m of crop row, respectively. Full-season competition resulted in seed cotton yield reductions by spurred anoda, velvetleaf, and prickly sida at 8, 16, and 64, plants/12 m of crop row, respectively. Competition from 2 weeks after cotton emergence until harvest by spurred anoda at 16 plants/12 m, and velvetleaf or prickly sida at 64 plants/12 m, reduced yields. Spurred anoda, velvetleaf, or prickly sida competition 4 to 6 weeks after cotton emergence until harvest did not reduce the seed cotton yields. Venice mallow competition did not reduce yields at any density or competition period.