Field experiments conducted at four locations in Georgia and two locations in Florida during 1992 and 1993 evaluated AC 263,222 application rates and timings, systems, and mixtures for weed control, peanut injury, and yield. All rates of AC 263,222 applied early POST (EPOST) or POST controlled Ipomoea morningglories and smallflower morningglory at least 90%, and purple and yellow nutsedge at least 81%. Florida beggarweed and sicklepod control generally was highest when metolachlor was applied PPI followed by AC 263,222 applied EPOST at 71 g/ha, AC 263,222 at 27 or 36 g/ha plus bentazon plus paraquat applied POST, or with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Acifluorfen and acifluorfen plus bentazon reduced Florida beggarweed and sicklepod control at several locations when applied in mixture with AC 263,222. Common ragweed and hairy indigo control were 85 to 95% with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Highest peanut yields were obtained with treatments providing high levels of weed control.

Field and greenhouse studies were conducted to evaluate selected PRE-applied herbicides for sprangletop control. In greenhouse studies, oxadiazon and dithiopyr provided excellent (> 89%) red sprangletop (L. filiformis) control. Pendimethalin and metolachlor + atrazine provided good (80–89%) to excellent control for 6 mo and 2 mo during studies 1 and 2, respectively. Isoxaben and atrazine provided poor (< 70%) control during both greenhouse studies. In field studies, good to excellent bearded sprangletop (L. fascicularis) control followed dithiopyr, pendimethalin, metolachlor, and metolachlor + atrazine treatments. Dithiopyr at 0.8 kg ai/ha provided best (> 95%) sprangletop control throughout the 6-mo testing period. Under field conditions, control was inconsistent following oxadiazon with good to excellent control during one study and poor control in another study. Better or equal control than metolachlor + atrazine followed dithiopyr, pendimethalin, and metolachlor alone treatments. Oxadiazon also provided similar or better control than metolachlor+atrazine in three of four studies. Over all studies, dithiopyr provided best sprangletop control, followed by metolachlor, metolachlor + atrazine, pendimethalin, and oxadiazon. Isoxaben and atrazine treatments provided poorest or inconsistent sprangletop control.

Abstract Field studies in 1990 and 1991 at Tifton, GA and Gainesville, FL evaluated the response of Florunner, Southern Runner, and NC 7 peanut to multiple herbicide applications. A split-split plot experimental design was used with peanut cultivars as main plots. Sub-plots were four levels of chloroacetamide herbicides applied sequentially preplant incorporated and at vegetative emergence. Sub-subplots were five postemergence herbicide treatments. All herbicides were applied at registered rates and times of application. There were no interactions between cultivars, choloracetamide, and/or postemergence herbicides for canopy width, yield, and grade of peanut. There were no interactions between chloroacetamide and postemergence herbicides for the same parameters. Main effects were the only sources of significant (P = 0.05) differences in the data. Based on these results, unusual precautions in using these herbicide combinations on these cultivars are not needed.

Garden tansy (Janacetum vulgare), a useful perennial herb from Europe and Asia, has now become naturalized-and something of a weed problem-in the United States.

Root growth was observed within 1 week following tall fescue placement in the greenhouse. At this time, the shoots were clipped to 5 cm. Treatments were then applied using bluegrass to four growth retardants. J. Amer. SoC. Hort. Sci. 110:765-769. Dernoeden, P.H. 1982. Effects of growth retardants applied three successive years to a Kentucky bluegrass turf. Proc. Northeast Weed Sci. HORTSCIENCE 25(5):581. 1990.

Abstract Field experiments were conducted in 1983 and 1984 on a Dothan loamy sand at Headland, AL to evaluate herbicide systems for minimum tillage peanut (Arachia hypogaea L. Florunner) production. The influence of minimum tillage-herbicide systems on weed control, peanut yield, market grade, and net returns were examined. Two minimum tillage-herbicide systems provided greater yield and higher net returns with equivalent control of Texas panicum (Panicum texanum Buckle.) and Florida beggarweed [Desmodium tortuosum (SW.)DC] as compared to a conventional tillage-herbicide system. One of these systems included oryzalin [4-(dipropylamino)-3, 5-dinitrobenzenesulfonamide] and paraquat (1, 1′-dimethyl-4,4′bipyridinium ion) applied preemergence followed by an early postemergence application of acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide] and dinoseb [2-(1-methylpropyl)-4,6-dinitrophenol] and a postemergence-directed application of cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile). The other system included benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine] and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2)methoxy-1-methylethyl)acetamide) applied preplant-incorporated within-the-row followed by an early postemergence application of dinoseb and ethalfluralin [N-ethyl-N-)2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine] and a postemergence-directed application of paraquat. Herbicide inputs for these two minimum tillage-herbicide systems were greater than for the conventional tillage-herbicide system.

Abstract Field experiments were conducted from 1981 through 1983 on a Dothan sandy loam (Plinthic Paleudults) at Headland, Alabama, to investigate the effects of row patterns and weed management systems on weed control, peanut yield, and net returns to land and management. Treatments consisted of three row patterns, a) conventional 91-cm rows, b) dual twin 18-cm rows, and c) triple twin 18-cm rows, and six weed management systems ranging from none to various combinations of herbicide and mechanical inputs. The experimental area was naturally infested with bristly starbur (Acanthospermum hispidum DC), sicklepod (Cassia obtusifolia L.), Florida beggarweed [Desmodium tortuosum (Sw.) DC.], large crabgrass [Digitaria sanguinalis (L.) Scop.], and Texas panicum (Panicum texanum Buckl.). Results showed that weed control was affected somewhat by row patterns with broadleaf weeds being more responsive to row pattern manipulation than grass weeds. Weed fresh weights were generally lower as row patterns narrowed from conventional 91-cm spacing, however exceptions did occur. Highest yields and net returns were obtained when peanuts were planted in the dual twin 18-cm rows and weed management included benefin applied preplant incorporated, plus alachlor applied preemergence, and two timely cultivations.