Vol. 54â2000 - NorthEastern Weed Science Society
Vol. 54â2000 - NorthEastern Weed Science Society Vol. 54â2000 - NorthEastern Weed Science Society
ETHOFUMESA TE RESISTANT CREEPING BENTGRASS? T. L. Watschke and1. A. Borger' ABSTRACT In November of 1993, a patch of creeping hentgrass growing in a golf course fairway that hadbeen suhject to a total of twelve applications ofethofumesate at O.5lhs ailA from 1989 to 1993was sampledforidentificationandplantincreasepurposes.Twelve three-quarterinchplugs wereremovedfromthepatchandwere transferredto a greenhouseandpottedin four-inchpots. A positive identificationforcreepingbentgrasswasmadeandtheplugs were grownin thepots untilSeptemberof 1994. At thattime,a portionof thebentgrassin each pot was transferredto a flatandallowedto increaseas wastheturfthatremainedin thepot. Anotherportionfromeach pot was planted in the field to assess seed production potential. By March of 1995, the pots had filled in and a phytotoxicity stody wasconducted using rates of ethofumesate that ranged from 1.5 to 12.51bs ailA from a single application. No phytotoxicity was observed. In April of 1996, the bentgrass in the flats was harvested by cutting stolons (with threeto four nodes) with a shears and placing them in water. After all the flats were harvested, the stolons were transferred to the ValentineResearchCenterwhereaneighthundredsquarefootareawas stolonizedusingthe harvested material. Later in 1996, the first seed was harvested from plants space planted in 1994. This seed was used to establish twelve (one for eacb original flat) plots in an area adjacent to the sprigged plot. In October of 1996, a phytotoxicity experiment was conducted on the sprigged plots. Ethofumesate was applied in October and twice in November at rates ranging from I to 4 Ibs ailA for each application. Phytotoxicity was rated in the spring of 1997 and none was found. Also in 1997, more plot area was established using stolons for one area and a blend of the seed fromall twelve sources(eachpot) fortheotherarea.Researchon this area,whichcontainsplots of five other creeping bentgrasses (all conunercially available) andlocally produced annual bluegrass is under the direction of Dr. David Huff, Penn State's turfgrass breeder. Experiments arecurrentlyunderway to furtherdocumenthedegreeof apparentresistancethatthe selected creeping hentgrass possesses. In addition, research will be conducted soon to ascertain whether the observed resistanceltolerance has a genetic basis that could betransferable. 'Professor andResearchAssistant, respectively,Departmentof Agronomy,PennStateUniversity,University Parle,PA, 16802 100
LATERAL DEVELOPMENT OF PLANT oaowra REGULATOR TREATED 'TIFWA Y' BERMUDAGRASS MJ. Fagemess and F.H. Yelverton' ABSTRACT The ability of plant growth regulators (pGRs), such as trinexapac-ethyl (TE) and paclobutrazol (PB), to suppress shoot biomass production and enhance shoot density in Tifway' bermudagrass (Cynodon dactylon (L.) Pers. x Cynodon transvoolensis [Burtt Davy)] has been docwnented. However, determination of how PGRs affect lateral developmentof thisspecies remainsa necessityfor completeunderstandingof how they affect growthanddevelopment.Researchwas conductedin a greenhouseover two years to investigate how various application patterns of either TE or PB affect both basic growth and lateral development patterns in established 'Tifway' bermudagrass. 10-em sod cores were established in 23-em pots and were maintained at a 1.9 cm cutting height. All pots were subirrigated and were fertilized at 49 kg N/halmonth. Trinexapac-ethyl and PB were applied once, twice, or three times during the experiment at 0.11 and 0.56 kg ai./ha, respectively.Both TE andPB inhibitedshootbiomassproduction.Paclobutrazol, especially applied two or three times, had the greatest effect on this measured parameter. Post inhibition growth enhancement (pIGE) was evidenced for both PGRs and was most pronounced when sequential applications were minimized. Shoot density was enhanced by either PGR. However, the duration of such enhancements by TE was dependent upon sequential applications while this dependency did not exist for PB. Stolon length was unaffected by TE in either year of the experiment. PB significantly reduced stolon length in bothyears;this suppressiveeffect was dependentuponsequentialapplicationsin 1998 but not in 1999. PB was the only PGR that affected stolon nwnbers emerging from the sod core. However, this effect, characterized by reductions in stolon number. was dependentuponsequentialapplicationsof PD. Threeapplicationsof PB resultedin a twofold increasein overall sodcore areasin 1998 while maximumsuch increaseswith TE were 30-40%. The three-application regime with PB did not produce the same effects in 1999. However, core area was maximizedin 1999 in pots treatedwith one or two applications of PB. The stronger suppressive effect of PB on 'Tifway' bermudagrass growth did not relate to decreased core area in this experiment. It is believed that strong suppressionof stolon lengthwith PB resultsin morerapidincorporationof these tissues intotheperceivedcanopy.Theabsenceof TEeffectson stolonlengthaffectedtheoverall outwarddevelopmentof TE treatedcores. However,enhancementsof measurableshoot densitymay have accountedfor slightincreasesin TEtreatedcores. Resultssuggest that PGRs may help facilitate 'Tifway' bermudagrass establishment. However, the suppressiveandpersistenteffects ofPB maynecessitatehighersprigplantingdensitiesto maximizethe utility of this PGR. , Research Assistant and Assoc. Prof., Crop Science Dept.,North Carolina State University, Raleigh, NC 27695-7620 101
- Page 49 and 50: COMPARISON OF WEED CONTROL SYSTEMS
- Page 51 and 52: Table I Mean Percent Weed Control V
- Page 53 and 54: SMALL GRAIN WEED CONTROL - NEW WEED
- Page 55 and 56: MODE OF ACTION, ABSORPTION, TRANSLO
- Page 57 and 58: INFLUENCE OF CROWNVETCH WITH AND WI
- Page 59 and 60: lRUMPETCREEPER, HONEYVINEMILKWEED,A
- Page 61 and 62: FLUFENACET PLUS METRIBUZIN PLUS ATR
- Page 63 and 64: CONTROLLING ASTERACEAE WEEDS WITH R
- Page 65 and 66: 0... Figure1. GerminationRateof Roo
- Page 67 and 68: BIOLOGICALLY BASED WEED CONTROL STR
- Page 69 and 70: NON·NATIVE VASCULAR FLORA OF BISCA
- Page 71 and 72: principally in ruderal sites. lawns
- Page 73 and 74: EVALUATION OF AZAFENlDIN FOR PREEME
- Page 75 and 76: AUTOMATING MONITORING OF ROADSIDE W
- Page 77 and 78: Table I: Swnmary of brush managemen
- Page 79 and 80: Table I: Sequence codes and general
- Page 81 and 82: IR-4 ORNAMENTAL RESEARCH PROGRESS F
- Page 83 and 84: personnel with many of the illegal
- Page 85 and 86: TOLERANCE OF ORNAMENTAL GROUNDCOVER
- Page 87 and 88: MUGWORT CONTROL WITH CLOPYRALID AND
- Page 89 and 90: POTENTIAL WEEDINESS OF SEVERAL NEW
- Page 91 and 92: Table I: Identification, morphologi
- Page 93 and 94: Trifolium tricolor 232 26 62 0 18 S
- Page 95 and 96: NUTRIENT REMOVAL BY WEEDS IN CONTAI
- Page 97 and 98: CONTROL OF POAANNUA FROM MULTIPLE S
- Page 99: ANNUAL BLUEGRASS (PDaannual CONTROL
- Page 103 and 104: RE-ROOTING OF FOUR VARIETIES OF CRE
- Page 105 and 106: Table 2. Top growth weights (fresh)
- Page 107 and 108: CONTROL OF DALLISGRASS IN COOL SEAS
- Page 109 and 110: Kentucky bluegrass was rated to hav
- Page 111 and 112: Table 2. Fresh weight (grams) barve
- Page 113 and 114: MANAGING FENOXAPROP RESIST ANT CRAB
- Page 115 and 116: ADVANCED FORMULATION TECHNOLOGY FOR
- Page 117 and 118: Table I. Preemergence smooth crabgr
- Page 119 and 120: 0.57EW at O.l21bs ai/A plus Confron
- Page 121 and 122: EFFICACY OF DITHIOPYR FORMULATIONS
- Page 123 and 124: EFFECTS OF DROUGHT ON THE INTERFERE
- Page 125 and 126: WEED MANAGEMENT WITH HALOSULFURON I
- Page 127 and 128: WEED CONTROL IN SWEET CORN WITH CAR
- Page 129 and 130: COMPARISON OF USING LEAF AREA AND W
- Page 131 and 132: RESULTS OF NEW YORK VINEYARD TRIALS
- Page 133 and 134: HERBICIDE TOLERANCE IN CRANBERRIES
- Page 135 and 136: Classification based on action on a
- Page 137 and 138: EFFECTS OF SEVERAL POTENTIALLY USEF
- Page 139 and 140: Supplement of the 53 rd Annual Meet
- Page 141 and 142: with society activities to anyone.
- Page 143 and 144: WINTER SQUASH CULTIVARS DIFFER IN R
- Page 145 and 146: INCORPORATING QUINCLORAC IN AUTUMN
- Page 147 and 148: Control efforts aim to eradicate bo
- Page 149 and 150: Table I Weed canopy, insect and dis
LATERAL DEVELOPMENT OF PLANT oaowra REGULATOR TREATED<br />
'TIFWA Y' BERMUDAGRASS<br />
MJ. Fagemess and F.H. Yelverton'<br />
ABSTRACT<br />
The ability of plant growth regulators (pGRs), such as trinexapac-ethyl (TE) and<br />
paclobutrazol (PB), to suppress shoot biomass production and enhance shoot density in<br />
Tifway' bermudagrass (Cynodon dactylon (L.) Pers. x Cynodon transvoolensis [Burtt<br />
Davy)] has been docwnented. However, determination of how PGRs affect lateral<br />
developmentof thisspecies remainsa necessityfor completeunderstandingof how they<br />
affect growthanddevelopment.Researchwas conductedin a greenhouseover two years<br />
to investigate how various application patterns of either TE or PB affect both basic<br />
growth and lateral development patterns in established 'Tifway' bermudagrass. 10-em<br />
sod cores were established in 23-em pots and were maintained at a 1.9 cm cutting height.<br />
All pots were subirrigated and were fertilized at 49 kg N/halmonth. Trinexapac-ethyl and<br />
PB were applied once, twice, or three times during the experiment at 0.11 and 0.56 kg<br />
ai./ha, respectively.Both TE andPB inhibitedshootbiomassproduction.Paclobutrazol,<br />
especially applied two or three times, had the greatest effect on this measured parameter.<br />
Post inhibition growth enhancement (pIGE) was evidenced for both PGRs and was most<br />
pronounced when sequential applications were minimized. Shoot density was enhanced<br />
by either PGR. However, the duration of such enhancements by TE was dependent upon<br />
sequential applications while this dependency did not exist for PB. Stolon length was<br />
unaffected by TE in either year of the experiment. PB significantly reduced stolon length<br />
in bothyears;this suppressiveeffect was dependentuponsequentialapplicationsin 1998<br />
but not in 1999. PB was the only PGR that affected stolon nwnbers emerging from the<br />
sod core. However, this effect, characterized by reductions in stolon number. was<br />
dependentuponsequentialapplicationsof PD. Threeapplicationsof PB resultedin a twofold<br />
increasein overall sodcore areasin 1998 while maximumsuch increaseswith TE<br />
were 30-40%. The three-application regime with PB did not produce the same effects in<br />
1999. However, core area was maximizedin 1999 in pots treatedwith one or two<br />
applications of PB. The stronger suppressive effect of PB on 'Tifway' bermudagrass<br />
growth did not relate to decreased core area in this experiment. It is believed that strong<br />
suppressionof stolon lengthwith PB resultsin morerapidincorporationof these tissues<br />
intotheperceivedcanopy.Theabsenceof TEeffectson stolonlengthaffectedtheoverall<br />
outwarddevelopmentof TE treatedcores. However,enhancementsof measurableshoot<br />
densitymay have accountedfor slightincreasesin TEtreatedcores. Resultssuggest that<br />
PGRs may help facilitate 'Tifway' bermudagrass establishment. However, the<br />
suppressiveandpersistenteffects ofPB maynecessitatehighersprigplantingdensitiesto<br />
maximizethe utility of this PGR.<br />
, Research Assistant and Assoc. Prof., Crop <strong>Science</strong> Dept.,North Carolina State<br />
University, Raleigh, NC 27695-7620<br />
101
Change language