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Junglerice has become a major weed in the mid-south and other areas of the United States. Glyphosate resistance has been documented in junglerice populations and is part of the reason for the increase in its prevalence. However, reduced junglerice control with glyphosate + dicamba and clethodim + dicamba mixtures has been observed in many production fields where glyphosate resistance has not yet evolved. Therefore, research was conducted to assess reduced junglerice control with glyphosate and clethodim when applied with dicamba. Adding dicamba to the spray tank with glyphosate reduced junglerice control by 27%. Adding dicamba to the spray tank with clethodim reduced junglerice control by 11%. The use of Turbo Teejet Induction (TTI) nozzles reduced junglerice control an additional 8% compared to applications with an air induction extended range (AIXR) nozzle. When a drift reduction agent (DRA) was added to dicamba mixtures with glyphosate or clethodim, junglerice control was reduced 36%. Junglerice control was similar with the glyphosate + dicamba treatment compared to the glyphosate + 2,4-D mixture. There was no interaction between nozzles and herbicide treatment. Regardless of herbicide treatment junglerice control was always lower when applied with the ultracourse TTI nozzle. Many applicators in Tennessee prefer to make one application of glyphosate + dicamba in a mixture to save time (authors' personal experience). These results show that the addition of dicamba to glyphosate or clethodim applied with labeled nozzles and a DRA results in reduced junglerice control and should be avoided. Nomenclature: junglerice; Echinochloa colona (L.) Link

Junglerice has become a major weed in Tennessee cotton and soybean fields. Glyphosate has been relied on to control these accessions over the past two decades, but in recent years cotton and soybean producers have reported junglerice escapes after glyphosate + dicamba and/or clethodim applications. In the growing seasons of 2018 and 2019, a survey was conducted of weed escapes in dicamba-resistant (DR) crops. Junglerice was the most prevalent weed escape in these DR (Roundup Ready Xtend®) cotton and soybean fields in both years of the study. In 2018 and 2019, junglerice was found 76% and 64% of the time in DR cotton and soybean fields, respectively. Progeny from junglerice seeds collected during this survey was screened for glyphosate and clethodim resistance. Seventy percent of the junglerice accessions tested had an effective relative resistance factor to glyphosate of 3.1 to 8.5. In all, 13% of the junglerice accessions could no longer be effectively controlled with glyphosate. This research also showed that all sampled accessions could still be controlled with clethodim in a greenhouse environment, but less control was observed in the field. These data also suggest that another cause for the poor junglerice control is dicamba antagonism of glyphosate and clethodim activity. Nomenclature: Clethodim; dicamba; glyphosate; junglerice [Echinochloa colona (L.) Link]; cotton (Gossypium hirsutum L.); soybean [Glycine max (L.) Merr.]

Several species of aphids (Hemiptera: Aphididae) infesting wheat may reduce yield by the transmission of barley yellow dwarf (BYD). Neonicotinoid seed treatments and foliar application of insecticides are two common methods to control aphid infestations and reduce BYD. An analysis was carried out across 33 insecticide efficacy tests performed in west Tennessee during the last 11 yr to determine how insecticide seed treatments and/or a late-winter foliar insecticide application affected aphid populations, incidence of BYD, and yield. A significant decrease in springtime aphid populations and incidence of BYD was observed when using a seed treatment, a foliar insecticide application, or both. Average wheat yields were increased by 280–381 kg/ha (5.3–7.2%) if an insecticide seed treatment was used or when a foliar insecticide application was made. Compared with insecticide seed treatments, average springtime aphid populations and the incidence of BYD were lower when a foliar insecticide was applied. A foliar insecticide application made in addition to insecticide seed treatments increased yield by an average of 196 kg/ha (3.4%). The yield increases over the nontreated control suggest that wheat growers in west Tennessee can use insecticides to manage aphids and prevent transmission of BYD. Consideration of environmental conditions, whether or not insecticide seed treatments were used, and scouting can be used to help make decisions on when or if to apply foliar insecticides.