Postemergence Herbicide Suppression of Wheat, Triticum aestivum, Growing with Alfalfa, Medicago sativa

Abstract

Two field experiments were conducted in 1984 and 1985 to determine the effects of fluazifop, haloxyfop, and sethoxydim on the suppression of water uptake and competition of wheat to seedling alfalfa. In all cases, suppression of wheat growth and stand led to significant reduction in soil water use. The amounts of conserved soil water significantly correlated with increased numbers of alfalfa plants; the correlation coefficients, respectively, for mid- and late-summer plantings were 0.47 and 0.41 in 1984 and 0.90 and 0.86 in 1985. Conservation of soil water was attributed to growth reduction or cessation of wheat growth by the herbicides and, to some extent, suppression of wheat leaf transpiration. All of the three herbicides would be effective in controlling volunteer wheat in a new alfalfa planting.

Relative Susceptibility of Oats (Avena sativa) and Wheat (Triticum aestivum) to Fluazifop, Haloxyfop, and Sethoxydim

“…In some situations, particularly those involving no-tillage forage plantihgs, volunteer small grains not controlled can be detrimental to legume establish ment (3,4). Such is often the case when straw and chaff scattering devices are not used in combine har vesters because the straw is baled.…”