Weed competition in soybeans [Glycine max(L.) Merr. ‘Clark 63′] with planted stands of velvetleaf (Abutilon theophrastiMedic.), prickly sida (Sida spinosaL.), and Venice mallow (Hibiscus trionumL.) is reported. Weeds were planted 0, 10, 20, 30, and 40 days after soybeans and competed until soybeans matured. Soybean seed yields were reduced 720, 250, and 230 kg/ha by velvetleaf, Venice mallow, and prickly sida, respectively. Weeds that emerged with soybeans reduced yields 1,010 kg/ha. Weeds planted 10 days later reduced yields 480 kg/ha, but weeds planted 20 to 40 days after soybeans did not significantly reduced yield. Soybean yields were reduced regardless of weed placement in or between soybean rows. Weed competition reduced numbers of soybean pods per plant more than other soybean-yield components.

Associations among cattle stocking rate, precipitation, and eastern redcedar invasion, and possibly redcedar control measures were investigated. Redcedar numbers generally decreased as stocking rate increased. Precipitation had only a slight effect on invasion rate. Fire, cutting, and fenuron granules appear to effectively kill red cedar. Loamy upland range site consists of soils having medium-textured soil deep enough to support primarily big bluestem and Indiangrass in climax condition. Predominant slopes are 1 to 5%.

CGA-43089 [α-(cyanomethoximino)-benzacetonitrile], CGA-92194 {α-[(1,3-dioxolan-2-yl-methyl)imino] benzeneacetonitrile}, and MON-4606 [5-thiazolecarboxylic acid, benzyl ester, 2-chloro-4-(trifluoromethyl)], applied as seed treatments at 1.25 g/kg seed, prevented yield losses in grain sorghum [Sorghum bicolor(L.) Moench.] in the field due to metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], alachlor [2-chloro-2′, 6′-diethyl-N-(methoxymethyl)acetanilide] or acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-o-acetotoluidide] applied at 1.7, 2.2 and 1.7 kg/ha, respectively. CGA-92194, applied at 0.8 g/kg seed, prevented yield reduction from metolachlor applied at 4.5 kg/ha. MON-4606 was more effective in protecting grain sorghum when applied as a seed treatment than when applied in the furrow with a clay or sand granule as carrier.

Kansas growers wish to improve broadleaf weed control in soybeans [Glycine max (L.) Merr.] grown in sandy soils with high pH or low organic matter content. Metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5 (4H)‐one] applications would effectively control broadleaf weeds on such soils; however, crop injury risk would also be present. Thus, a field experiment was initiated to determne if a 3‐week interval between herbicide application and planting or cultivation after soybean emergence improved tolerance of soybeans grown on a soil with a high pH and low organic matter content. Metribuzin was applied at 0.6 or 1.1 kg/ha and incorporated prior to soybean planting in a Haynie very fine sandy loam (coarse‐silty, mixed, calcareous, mesic Typic Udifluvent) with pH of 7.9 and 0.7% organic matter content in 1978 and 1979. Visual injury of 4‐week‐old plants was less in 1978 but more in 1979 when metribuzin was applied 3 weeks before planting rather than immediately before planting. Injury in 7‐week‐old plants was not significantly affected by time of metribuzin applications in 1978 but was greater from applications immediately before planting compared to applications 3 weeks prior to planting in 1979. Injury differences were attributed to rainfall quantity and pattern. The meribuzin applications at 0.6 or 1.1 kg/ha 3 weeks prior to planting did not affect soybean yields either year even though the higher rate reduced plant stand and plant height. Yields were reduced only when metribuzin was applied at the higher rate immediately before planting. Cultivation at 3 and 7 weeks after soybean planting did not significantly affect soybean tolerance either year.

The influence of acetamide herbicide applications on efficacy of CGA-43089 [α-(cyanomethoximino)-benzacetonitrile] in grain sorghum [Sorghum bicolor(L.) Moench] was studied under field conditions. Acetamide herbicides applied preplant and incorporated on a Haynie very fine sandy loam caused more grain sorghum injury in 1979 than in 1978. Reductions in plant population, plant height and yield, along with delay in maturity, were severe for acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-O-acetotoluidide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], and alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide]; moderate for diethatyl [N-(chloroacetyl)-N-(2,6-diethylphenyl)glycine], xylachlor [2-chloro-N-(2,3-dimethylphenyl)-N-(1-methylethyl)acetamide], and butam [2,2-dimethyl-N-(1-methylethyl)-N-(phenylmethyl)propanamide]; and did not occur for propachlor (2-chloro-N-isopropylacetanilide) treatments. Acetamide herbicides caused less grain sorghum injury on a Reading silt loam than on a Haynie very fine sandy loam in 1979. CGA-43089 applied as a seed treatment protected grain sorghum grown on soils treated with metolachlor, alachlor, diethatyl, or xylachlor. Metolachlor-triazine combinations at five locations in Kansas reduced yields at two locations. CGA-43089 provided protection from metolachlor injury at those two locations.