Effect of Herbicides on Weed Control and Nitrate Accumulation in Table Beets1

Abstract

Abstract Good broadleaf weed control was achieved in table beets (Beta vulgaris L.) with cycloate, CNP, pebulate, lenacil, pyrazon (preplant application = pre), IMC 3950, TCA + pyrazon and pebulate (preplant incorporation = ppi) followed by pyrazone (postplant incorporation = post), while fair to good weed control was achieved with EPTC, propachlor and solubor. Poor weed control was obtained from CDEC, chlorpropham, pyrazon (post) and TCA. Yields expressed as $/ha or tons/ha were reduced by chlorpropham, lenacil, CNP and TCA. Nitrate-N was significantly increased in blades of beets by lenacil, pyrazon (pre) and CNP. The herbicides cyloate, CNP, EPTC, pebulate (ppi) — pyrazon (post), and TCA + pyrazon increased NO3-N concentrations in petioles. TCA + pyrazon and CNP increased NO3-N in beet roots, while CDEC, chlorpropham, solubor and pyrazon (post) decreased NO3-N. Total N concentration in the leaf blades was not affected by any of the herbicide treatments. Total N in petioles increased when TCA, chlorpropham, lenacil and CNP were used. TCA, chlorpropham, lenacil and CNP increased root total N.