Imazethapyr and Paraquat Systems for Weed Management in Peanut (Arachis hypogaea)

Abstract

Field studies conducted at six locations in Georgia and one location in Virginia evaluated imazethapyr and imazethapyr mixtures for weed control, crop tolerance, and peanut yield. Imazethapyr applied early postemergence controlled bristly starbur, coffee senna, common cocklebur,Ipomoeaspecies, jimsonweed, prickly sida, and smallflower morningglory at least 91% and controlled yellow and purple nutsedge 88 and 98%, respectively. Paraquat plus bentazon applied early postemergence did not control the aforementioned weeds as well as imazethapyr or imazethapyr mixtures. Paraquat applied with imazethapyr reduced bristly starbur control 15% compared to imazethapyr alone but did not influence control of the other species. Imazethapyr control of bristly starbur was not improved by the addition of bentazon. Sicklepod control was less than 24% with imazethapyr and was at least 58% with imazethapyr plus paraquat Imazethapyr plus paraquat controlled sicklepod better than paraquat plus bentazon at three of the four locations evaluated. Imazethapyr did not control Florida beggarweed, while imazethapyr plus paraquat controlled at least 53%. Peanut injury was minimal 30 d after application for all treatments.

Imazethapyr Systems for Peanut (Arachis hypogaea L.)

“…The standard controlled prickly sida 100% (Table 1). Neither paraquat nor 2,4-DB alone or in combination provides adequate prickly sida control (9). All other treatments controlled prickly sida at least 90%.…”

“…Pendimethalin does not have appreciable activity on the large seeded broad leaf weed species or yellow nutsedge found in these studies, consequently this herbicide will not be discussed further (9,13). and large crabgrass [Digitaria sanguinalis (L.)] (data not shown).…”

“…Imazethapyr was the first herbicide in peanut to provide residual control of numerous annual broadleaf weeds and perennial sedges (3,5,7,9,10,11). Imazethapyr was the first herbicide in peanut to provide residual control of numerous annual broadleaf weeds and perennial sedges (3,5,7,9,10,11).…”

“…Imazethapyr does not control Florida beggarweed [Desmodiumtortuosum (SW.) DC] and sicklepod (9,10,11), the two most common and troublesome annual broadleaf weeds in southeastern peanut production (2). Consequently, other herbicides must be used.…”

“…Previous research reported that imazethapyr controlled prickly sida and spurred anoda [Anoda cristata (L.) Schlecht.] Later research showed that a POST application of paraquat + imazethapyr at 72 g/ha controlled bristly starbur, coffee senna, common cocklebur (Xanthium strumarium L.), Ipomoea morningglories, prickly sida, and smallflower morningglory better than a paraquat + bentazon mixture (9). Later research showed that a POST application of paraquat + imazethapyr at 72 g/ha controlled bristly starbur, coffee senna, common cocklebur (Xanthium strumarium L.), Ipomoea morningglories, prickly sida, and smallflower morningglory better than a paraquat + bentazon mixture (9).…”