HERBACEOUS WEEED CONTROL IN FIRST – YEAR LOBLOLLY PINE PLANTATIONS USING OUST XP, OUST EXTRA, OUSTAR, MATRIX, AND STEADFAST A. W. Ezell, J. L. Yeiser, and L. R. Nelson

Acknowledgements Dupont Chemical CompanyDupont Chemical Company Plum Creek Timber CompanyPlum Creek Timber Company Boise-CascadeBoise-Cascade

Background Herbaceous weed control is an essential component of loblolly pine plantation establishmentHerbaceous weed control is an essential component of loblolly pine plantation establishment Evaluation on new or currently labeled products may produce new options for land managersEvaluation on new or currently labeled products may produce new options for land managers

MATERIALS AND METHODS STUDY SITESSTUDY SITES –MISSISSIPPI Plum Creek Timber Co. landPlum Creek Timber Co. land Previous Cover = mixed pine-hardwood natural standPrevious Cover = mixed pine-hardwood natural stand Harvested – 2002Harvested – 2002 Chemical site preparation – 2003Chemical site preparation – 2003 Subsoiled – 2003Subsoiled – 2003 Hand planted with 1-0 loblolly – January 2004Hand planted with 1-0 loblolly – January 2004 Soils = sandy clay loam, pH = 5.3Soils = sandy clay loam, pH = 5.3

TexasTexas –Boise-Cascade land –Harvested – Oct, 2002 –Shear – July, 2003 –Burn – August, 2003 –Machine planted with 1-0 loblolly – January, 2004 –Soil = Eastwood fine sandy loam

South CarolinaSouth Carolina –Nonindustrial private land –Retired agricultural field –Disced – Summer 2003 –Machine planted with 1-0 loblolly – January, 2004 –Soil = clay loam

List of treatments in 2004 DuPont herbaceous weed control project Treatment No. 1 Herbicide and Rate/A (oz) 1Matrix (2) 2Matrix (4) 3Steadfast (1) 4Steadfast (2) 5Oust Extra (2) 6Oust Extra (3) 7Matrix (2) + Oust Extra (2) 8Steadfast (1) + Oust Extra (2) 9Oust Extra (3) + Arsenal AC (4) 10Oust Extra (2) + Arsenal AC (4) 11Matrix (2) + Arsenal AC (4) 12Steadfast (1) + Arsenal AC (4) 13Arsenal AC (4) 14Oust XP (2) + Arsenal AC (4) 15Oustar (13) 16Untreated 1 Treatments 1,2,3,4,7, and 8 had Timbersurf 90 added (12.8 oz/A)

ApplicationApplication –CO 2 –powered backpack sprayer –4-nozzle boom with 8001 tips –10 gpa –5-foot bands centered over planted row –Dates of application MS - April 13, 2004MS - April 13, 2004 TX - April 5, 2004TX - April 5, 2004 SC – April 14, 2004SC – April 14, 2004

Experimental Design –MS = RCB with 4 replications –SC = RCB with 4 replications –TX = RCB with 4 replications

Evaluation Ocular evaluation of percent ground coverage at 30, 60, 90, and 120 DATOcular evaluation of percent ground coverage at 30, 60, 90, and 120 DAT Tree vigor at 30-day intervalsTree vigor at 30-day intervals Initial height and groundline diameter (GLD)Initial height and groundline diameter (GLD) Height and GLD - 1GSATHeight and GLD - 1GSAT

Analysis ANOVAANOVA DNMRTDNMRT

RESULTS

Major Herbaceous Species MS Bull paspalum*, panic grasses, Andropogon, late boneset, goldenrod, fireweed, common ragweed, dogfennel TX panic grasses, Chasmanthium, Paspalum, Andropogon, late boneset, common ragweed, dogfennel, purple cudweed SC perennial ryegrass, wild radish, Johnsongrass, common ragweed, panic grasses

30 DAT

60 DAT

30 DAT

60 DAT

90 DAT

120 DAT

Summary No treatments resulted in negative impact on loblolly seedlingsNo treatments resulted in negative impact on loblolly seedlings Only treatments to provide “best” control in all three states were Oust Extra + Arsenal AC combinationsOnly treatments to provide “best” control in all three states were Oust Extra + Arsenal AC combinations Oustar and Oust XP + Arsenal AC treatments provided “best” control at two of three locationsOustar and Oust XP + Arsenal AC treatments provided “best” control at two of three locations Matrix and Steadfast did not provide acceptable control on these sitesMatrix and Steadfast did not provide acceptable control on these sites Good to be able to test new products and/or applications, but sometimes, the answer is “no”Good to be able to test new products and/or applications, but sometimes, the answer is “no” Oust Extra + Arsenal AC combinations provided excellent results on a wide variety of speciesOust Extra + Arsenal AC combinations provided excellent results on a wide variety of species