A bermudagrass [Cynodon dactylon (L) Pers. × C. transvaalensis Burtt-Davy `Tifgreen'] lawn in the transition zone (about lat. 35°N) was treated in late March for 3 years with a high and a low level each of benefin, bensulide, DCPA, oxadiazon, and siduron. Objectives were to determine if relationships exist between field environment and dates of preemergence herbicide applications for large crabgrass (Digitaria sanguinalis L. Scop.) control, the spring root decline (SRD) phenomenon, and herbicide phytotoxicity to the bermudagrass. Herbicide treatments in late March generally controlled large crabgrass, reduced total weed competition, and appeared to aid bermudagrass spring growth following winter dormancy. Herbicide injury to `Tifgreen' bermudagrass roots during SRD does occur under practical field conditions and was more severe when bermudagrass spring green-up occurred closer to the herbicide treatment date, as in 1982. Bermudagrass stand density was significantly reduced with the high level of siduron in 1980 and 1981, and with both levels of oxadiazon and siduron in 1982. Bensulide and oxadiazon, at both levels, gave 92% to 100% crabgrass control during all three treatment years. The high levels of benefin and DCPA in 1980, both levels of benefin and the high level of DCPA in 1981, and both levels of DCPA and the high level of benefin in 1982 gave crabgrass control in excess of 95%. Chemical names used: N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)-benzenamine (benefin), O,O-bis(1-methylethyl)-S-[2-[(phenylsulfony l)-amino]ethyl] phosphorodithioate (bensulide), dimethyl 2,3,5,6-tetra-chloro-1,4-benzenedicarboxylate (DCPA), 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(l,l-dimethylethyl)-l,3,4-oxadiazol-2 -(3H)-one (oxadiazon), N-(2-methylcyclohexyl)-N'-phenylurea (siduron).
Lloyd M. Callahan and Joe W. High Jr.
Bonnie L. Appleton and Jeffrey F. Derr
Disks of several geotextiles, paper, fiberglass, and black polyethylene were compared with the herbicides oxyfluorfen plus pendimethalin, oxadiazon, and oryzalin plus benefin for suppression of weed growth around container-grown Southwestern white pine (Pinus strobiformis Engelm.), Chinese pistache (Pistacia chinensis Bunge.), and `Fashion' azalea [Rhododendron indicum (L.) Sweet × `Fashion']. The greatest weed control was obtained with a combination geotextile-preemergence herbicide (trifluralin) disk, indicating a possible new method of container weed control. Several of the barrier materials, including heavy wrapping and compressed peatmoss papers, black polyethylene, and one spunbonded geotextile, were inferior due to degradation or to weeds growing around the disk edges or center hole. No difference in crop growth was noted among the treatments. Chemical names used: 2-chloro-1- (3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); N-(1-ethylpropyl)-3,4 -dimethyl-2,6-dinitrobenzenamine (pendimethalin); 3-[2,4-dichloro-5 -(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); 4-(dipropylamino) -3,5 -dinitrobenzenesulfonamide (oryzalin); N-butyl-N-ethyl-2,6 -dinitro-4-(trifluoromethyl) benzenamine (benefin); 2,6-dinitro-N,N-dipropyl-4-(ttifluoromethyl)benzenamine (trifluralin).
Joseph C. Neal and Andrew F. Senesac
Preemergent herbicide phytotoxicity was evaluated for six species of container-grown ornamental grasses: beach grass (Ammophila breviligulata Fern.), pampas grass [Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn.], tufted hair grass [Deschampsia caespitosa (L.) Beauvois.], blue fescue [Festuca ovina cv. glauca (Lam.) W.D.J. Koch], fountain grass [Pennisetum setaceum (Forssk.) Chiov.], and ribbon grass (Phalaris arundinacea cv. picta L.). Herbicides included isoxaben, metolachlor, MON 15151, napropamide, oryzalin, oxadiazon, pendimethalin, prodiamine, and trifluralin; the granular combination products of benefin plus trifluralin; and oxyfluorfen plus pendimethalin. Metolachlor, granular or spray, and oryzalin severely injured all species tested, except beachgrass, which was not injured by metolachlor granule. Napropamide injured pampas grass, fountain, grass, blue fescue, and tufted hair grass, but was safe on ribbon grass and beach grass. Pendimethalin, prodiamine, trifluralin; MON 15151, isoxaben, oxyfluorfen plus pendimethalin, and benefin plus trifluralin were safe on all six species. Chemical names used: N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine(benefin);N-[3-(1-ethyl-1-methylpropyl)5-isoxazolyl]-2,6-dimethoxybenzamide(isoxaben);2-chloro-N-(2-ethyl-6-methylphenyll-N-(2-methoxy-1-methylethyl)acetamide (metolachlor); S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicarbothioate(MON 15151);N,N-diethyl-2-(l-naphthalenyloxy)propanamide (napropamide); 4-(dipropylamino)-3,5-dinitro-benzenesulfonamide (oryzalin); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); N3,N3-di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine (prodiamine); 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine (trifluralin).
Sang Ryul Shim and B.J. Johnson
Creeping bentgrass (Agrostis palustris Huds.) putting greens are commonly infested with crabgrass (Digitaria spp.) and goosegrass [Eleusine india (L.) Gaertn.]; however, many herbicides have the potential to severely injure this turfgrass species. A field investigation was conducted over 2 years to determine the tolerance of creeping bentgrass to various herbicides. Trifluralin plus benefin (2.2 to 6.7 kg·ha-1), dithiopyr (0.37 to 1.1 kg·ha-1), and prodiamine (0.5 to 1.7 kg·ha-1) did not injure creeping bentgrass. Pendimethalin caused only slight injury when applied at 3.4 kg·ha-1, but injury increased in 1 of 2 years when applied at ≥6.7 kg·ha-1. Creeping bentgrass was severely injured when treated with benefin plus oryzalin (≥4.5 kg·ha-1), fenoxaprop (0.07 kg·ha-1), and oxadiazon (3.4 kg·ha-1) granular and WP formulations and, therefore, should not be applied to the turf. Chemical names used: N -butyl-N -ethyl-2, 6-dinitro-4-(trifluoromethyl) benzenamine (benefin); S,S -dimethyl 2-(difluoromethyl-4-(2-methylpropyl)-6-(trifluoromethyl-3, 5-pyridinedicarbothioate (dithiopyr); (±) 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoic acid (fenoxaprop); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); 3-[2,4-dichloro-5-(l-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); N -(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); 2,4-dinitro N,N -dipropyl-6-(trifluoromethyl)-1,3-benzenediamine (prodiamine); 2,6-dinitro-N-N -dipropyl-4-(trifluoromethyl)benzenamine (trifluralin).
Peter A. Dotray and Cynthia B. McKenney
Experiments were conducted to evaluate established and seeded buffalograss [Buchloe dactyloides (Nutt.) Engelm.] tolerance to herbicides applied preemergence at labeled use rates. Established buffalograss tolerated benefin, benefin plus oryzalin, benefin plus trifluralin, DCPA, dithiopyr, isoxaben, oryzalin, pendimethalin, and prodiamine. For established buffalograss treated with atrazine, diuron, or metolachlor, the injury rating was 27% to 71% at 6 weeks after treatment (WAT) and 22% to 84% at 15 WAT. Buffalograss tolerated cyanazine, metsulfuron, propazine, and pyrithiobac applied in the seedbed. Seeded buffalograss stands were reduced by alachlor, atrazine, dicamba, linuron, metolachlor, metribuzin, oryzalin, pendimethalin, and quinclorac. Stand reductions by dicamba (a preplant and postemergence herbicide), up to 100% at 4 WAT and up to 85% at 16 WAT, were those most severe. Seeded and established buffalograss showed excellent tolerance to a few preemergence herbicides that could be used effectively and safely to control weeds during establishment and maintenance of buffalograss. Chemical names used: 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide (alachlor); 6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine (atrazine); N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine (benefin); 2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile (cyanazine); dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate (DCPA); 3,6-dichloro-2-methoxybenzoic acid (dicamba); S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicarbothioate (dithiopyr); N′-(3,4-dichlorophenyl)-N,N-dimethylurea (diuron); N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide (isoxaben); N′-(3,4-dichlorophenyl)-N-methoxy-N-methylurea (linuron); 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide (metolachlor); 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one (metribuzin); 2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoic acid (metsulfuron); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); N 3,N 3-di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine (prodiamine); 6-chloro-N,N′-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine (propazine); 2-chloro-6-[(4,6-dimethoxy-2-pyrimidinyl) thio]benzoic acid (pyrithiobac); 3,7-dichloro-8-quinolinecarboxylic acid (quinclorac); Team™ [premix of 1.33% benefin and 0.67% 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] (trifluralin).
Kenneth Cropper, Gregg Munshaw, and Michael Barrett
environmental effects from chemical crabgrass control is to reduce usage rates. Dernoeden (2001) examined reduced preemergent herbicide rates over a 3-year time period and found only benefin with trifluralin and prodiamine alone still provided acceptable
Filippo Rimi, Stefano Macolino, and Bernd Leinauer
growth of ‘Meyer’ zoysiagrass was less injured than ‘Emerald’ or ‘Matrella’ after applications of benefin. More recently, further tolerance differences among zoysiagrasses have been pointed out with regard to other preemergence ( Johnson and Carrow, 1999
S. Christopher Marble, Andrew K. Koeser, and Gitta Hasing
+ trifluralin, oryzalin + benefin, and dimethenamid-p + pendimethalin) will generally offer broad-spectrum control and reduce the number of applications that must be made ( Gallitano and Skroch, 1993 ; Gilliam et al., 1989 ; Monaco and Hodges, 1974 ). Tank