Interference of Yellow Nutsedge (Cyperus esculentus) in 'Beauregard' Sweet Potato (Ipomoea batatas)

Field studies were conducted in 2013 at Houlka, MS and 2014 at Houston and Pontotoc, MS to determine the influence of yellow nutsedge density on 'Beauregard' sweet potato yield and quality. Treatments established 2 wk after transplanting (WAP) were yellow nutsedge densities of 0, 5, 10, 15, 30, 40, 50, and 90 shoots m(-2) within the planted row. No. 1 and marketable yield loss were fit to a rectangular hyperbola model. In 2013 predicted yield loss of no. 1 and marketable grades ranged from 23 to 96% and 18 to 80%, respectively for yellow nutsedge densities of 5 to 90 shoots m(-2). In 2014 predicted yield loss of no. 1 and marketable grades ranged from 7 to 74% and 6 to 67%, respectively for yellow nutsedge densities of 5 to 90 shoots m(-2). Yellow nutsedge shoot density increased linearly from 2 WAP to harvest. At Houston and Pontotoc, yellow nutsedge shoot density increased 2.3 and 7.6 times, respectively, for every one shoot present at 2 WAP.