Experiments were conducted to develop controls for cogongrass [Imperata cylindrica (L.) Beauv.] on noncrop areas. Single and multiple applications of herbicides were evaluated in field tests. All soil sterilants evaluated provided acceptable control. Single applications of TCA (trichloroacetic acid) at 56 kg/ha and dalapon (2,2-dichloro propionic acid) at 8.3 kg/ha controlled cogongrass without prolonged soil sterility. Multiple applications of amitrole (3-amino-s-triazole), paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), glyphosate [N-(phosphonomethyl)glycine] and dalapon markedly reduced cogongrass stands 1 year after application.

Interstate rights-of-way may serve as weed host reservoirs for the tarnished plant bug, an insect pest of cotton. Management of these rights-of-way may have an impact upon cotton pest management. In a 3-yr study, time of mowing, frequency of mowing, and sulfometuron methyl applied against overwintering rosettes influenced the cover of annual fleabane and wild carrot, which harbor tarnished plant bugs.

The objective of this study was to determine how selected herbicides affect sod tensile strength and rooting of mature and immature turfs of ‘Tifway’ bermudagrass. Both immature and mature turf had 100% ground cover, but only mature turf had tensile strength adequate for harvesting and handling. Sod tensile strength at 2, 4, and 8 weeks after application generally was unaffected by herbicide treatment, although imazapyr killed bermudagrass top growth. Root number and root length initially were depressed by imazapyr, bensulide, napropamide, sethoxydim, and sulfometuron at most rates and intervals tested. Eight weeks after treatment, root length, root number, and sod tensile strength for all treatments, except those with imazapyr, were similar to that of the untreated control.

Cogongrass [Imperata cylindrica (L.) Beauv.] was introduced into the Mobile Bay area of Alabama in 1911 or 1912. During the ensuing 60 years this rhizomatous weedy grass has spread into most of the southern portion of the state. Cogongrass has become a problem in agronomic and horticultural crops which are not intensively cultivated. Several currently available herbicides show promise of control.

Field experiments were conducted during 1968 to 1970 to determine the influence of time of herbicide application on control of kudzu [Pueraria lobata (Willd.) Ohwi]. Picloram (4-amino-3,5,6-trichloropicolinic acid) effectively controlled kudzu when applications were made as early as May 22 and as late as October 28. Acceptable control was obtained with rates of picloram 0.34 kg/ha or higher. In contrast, (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) was most effective when applied during the first half of summer. Essentially no control of kudzu was obtained from 2,4,5-T applied 1 week before the first killing frost.

Responses of the vegetative growth of cogongrass [Imperata cylindrica (L.) Beauv.] to temperature and photoperiod were studied in plants grown from stem and rhizome propagules collected from plants originating at four locations in southern Alabama and Mississippi. The plants were grown in four controlled-environment chambers with day/night temperature regimes of 23/17 C and 29/23 C, photoperiods of 12 h and 16 h, and photosynthetic photon flux densities (PPFD) of 650 μE(einsteins)m−2s−1. After 87 days, heights, leaf areas, total dry weights, rhizome numbers, and rhizome dry weights were significantly greater in plants grown at 29/23 C than at 23/17 C. Total dry weights, rhizome numbers, and rhizome dry weights were greater at the 16-h photoperiod than at 12 h. Plants grown from propagules from the McNeil, Mississippi population, which originated from an introduction from the Philippines, were significantly smaller than plants grown from propagules collected from populations thought to have originated from an introduction of cogongrass from Japan. Mathematical analysis of the growth data showed that the observed differences in dry matter production were more closely related to differences in leaf area duration than to differences in net assimilation rate.

Virginia buttonweed seeds germinated at temperatures between 15 and 40 C, with optimal germination occurring at 25 or 30 C in 12 h light alternated with 15 to 25 or 20 to 30 C in darkness, respectively. Germination rate was lower in continuous darkness than in light. Germination was reduced under simulated water stress conditions with less than 10% of seeds germinating at osmotic potentials below −0.3 MPa. Overall seed germination was reduced under simulated flooding conditions; greater germination occurred in aerated water than in unaerated water. Maximum germination occurred at pH 6. Seedlings emerged from depths as great as 8 cm, with maximum emergence occurring from 2 cm.

Ethofumesate, [(+)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] applied preemergence provided selective control of annual bluegrass (Poa annua L.) in perennial ryegrass (Lolium perenne L.) overseeded on dormant bermudagrass [Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt Davy ‘Tifdwarf’] golf greens. Control in excess of 95% was obtained with single applications at the 2.2 kg/ha rate in 2 of 3 yr, but multiple applications were required when ethofumesate was applied at 1.1 kg/ha or less. Ethofumesate caused temporary cessation of bermudagrass growth when applied in the fall. February applications slowed the spring transition to bermudagrass.

Sulfometuron, when applied as a foliar and/or soil application, prevented regrowth of bahiagrass. Sulfometuron application did not reduce regrowth of centipedegrass regardless of method of application. Sulfometuron was absorbed by the roots and foliage of centipedegrass and bahiagrass. Symplasmic translocation of the herbicide was evident in both species. Translocation of foliar-applied sulfometuron increased from approximately 1% at 48 h after application to 23% at 72 h in bahiagrass. Metabolism of sulfometuron was greater in centipedegrass (69% of foliar-applied, 10% of root-applied) at 72 h after application than in bahiagrass (30% of foliar-applied and 4% of root-applied). Tolerance of centipedegrass to sulfometuron appeared to be related to a high degree of herbicide metabolism in this species.

Mobility and sorption of radiolabeled sulfometuron {2-[[[[(4,6-dimethyl-2-pyrimidinyl)amino] carbonyl] amino] sulfonyl] benzoic acid} and imazapyr {(±)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridinecarboxylic acid} were evaluated in five soils representative of the major soil types in Alabama. Thin-layer soil chromatography indicated that sulfometuron was slightly more mobile (average Rf = 0.86) than imazapyr (average Rf = 0.79). Sulfometuron was more subject to sorption (average kd = 0.29) than imazapyr (average kd = 0.09) in batch equilibrium experiments. Least sorption of both herbicides occurred on clay soils, and maximum sorption occurred on a sandy clay. Similar results were obtained with a soil solution recovery technique. Sorption of both herbicides was exhanced by temporary reduction in soil water content and by lowering soil pH. The pH response of imazapyr was greater than that of sulfometuron.

Experiments were conducted to determine adsorption of methanearsonate by soils, soil separates, and reference clay minerals from solutions of disodium methanearsonate (DSMA), effects of soil type and pH on the leaching of surface-applied DSMA, and effects of soil type and added organic matter on the oxidation of the methyl carbon of methanearsonate.

Adsorption of methanearsonate by kaolinite and vermiculite increased with increasing concentration of DSMA in the equilibrium solution. Kaolinite and limonite adsorbed much more methanearsonate than vermiculite and montmorillonite. The clay fraction of Augusta silt loam adsorbed more methanearsonate than did the sand and silt fractions. Adsorption by whole soils was related generally to their clay contents.

Leaching with 20 successive 1-in increments of water removed 52% of surface-applied methanearsonate from Norfolk loamy sand. Rates of movement of DSMA in Norfolk loamy sand did not differ at three pH levels. About one-half of the applied methanearsonate remained in the surface inch of Decatur clay loam and none was leached below 6 in.

Oxidation of the methyl carbon of methanearsonate was associated with oxidation of soil organic matter in each soil. In three of the soils, there was no evidence of microbiological adaptation to methanearsonate. In Norfolk loamy sand, however, increasing decomposition of methanearsonate relative to soil organic matter occurred with time of incubation. Decomposition of added plant material in this soil enhanced the oxidation of methanearsonate.