Field experiments were conducted in 1991 and 1993 to evaluate flumioxazin alone and in various herbicide programs for weed control in peanut. Flumioxazin alone provided inconsistent control of annual grasses, while the addition of pendimethalin or trifluralin improved control considerably. Pitted morningglory (Ipomoea lacunosa L.) and ivyleaf morningglory [Ipomoea hederacea (L.) Jacq.] control was >75% when flumioxazin was used alone. Flumioxazin caused early season peanut stunting with some recovery within 4 to 6 wk. Postemergence applications of imazethapyr or lactofen increased peanut stunting.

Experiments were conducted from 1988 through 1991 to evaluate the effectiveness of imazethapyr alone and in combination with metolachlor for control of yellow and purple nutsedge. Imazethapyr alone at 0.07 kg ha–1controlled yellow nutsedge irregularly while the addition of metolachlor greatly improved control. Metolachlor preplant incorporated (PPI) followed by imazethapyr at ground-crack (GC) or postemergence (POST) controlled 72 to 96% of yellow nutsedge, whereas a tank-mix of metolachlor plus imazethapyr PPI controlled 85 to 96%. The addition of metolachlor to imazethapyr did not result in any improvement in control of purple nutsedge. Metolachlor plus imazethapyr PPI controlled ≥ 85% of purple nutsedge PPI, whereas imazethapyr POST controlled ≥ 94%.

Field studies conducted from 1989 through 1991 evaluated methods of metolachlor application including POST followed by irrigation for yellow nutsedge control and peanut response. Metolachlor PPI stunted peanut in two of three years while metolachlor applied at emergence, 10, 20, or 30 days after peanut emergence (DAE) caused no peanut injury. Metolachlor 20 DAE provided > 95% yellow nutsedge control. Metolachlor soil-applied and again POST controlled yellow nutsedge at least 70%; however, some peanut stunting was noted. Bentazon plus metolachlor at 2.24 kg ai/ha controlled yellow nutsedge at least 92% when applied 30 DAE. Peanut yields were consistently the highest with metolachlor PRE at 1.40 kg ai/ha followed by a POST application of 1.40 kg ai/ha at 45 DAE.

Field studies were conducted in 1988 and 1989 under dryland and irrigated conditions to determine effects of various herbicides for use in peanuts on weed control and peanut yield under a reduced tillage system. Under dryland and irrigated conditions, sethoxydim + acifluorfen consistently controlled Texas panicum. Paraquat + bentazon controlled Texas panicum poorly under dryland conditions. Pendimethalin + metolachlor provided ≥ 80% Texas panicum control under irrigated conditions.

Five runner peanut (Arachis hypogaeaL.) cultivars were treated With.f~ur dinitroaniline herbicide treatments or a postemergence herbicide treatment to determine the effect on pod yield and grade, p~rcen~age sound mature kernels + sound splits (SMK+SS). No yield differences due to the dinitroaniline herbicide treatments were noted in the three year study. Southern Runner and GK-7 were higher in yield in one of the three test years, however, no cultivar yield differences were noted in the other two years. Grades were lowerwith pendimethalin in the three years;grades oftrifluralin, ethalfluralin and benefin-treatedpeanuts were variable from year to year.