Update on 2009 Weed Science Research in the IR-4 Ornamental

Horticulture Program

C. Palmer, J. Baron, E. Veaand E. Lurvey

2009 IR-4 Weed Science Research

• 2008/2009 Herbicide Crop Safety– Over the top applications– First treatment soon after plants broke

dormancy– Second application 6 weeks after first

• Early Post-Emergent Efficacy– Bittercress– Oxalis– Spurge

Photo by C. Palmer

2008/2009 Herbicide Crop Safety

Participating ResearchersDr. John AhrensDr. Ed BesteDr. Rick BoydstonDr. Mark CzarnotaDr. Jeff DerrDr. Ray FrankMr. Ben FraelichMr. Tom FreibergerDr. Charles GilliamDr. Paul HarveyDr. Jim KlettDr. Heiner LiethDr. Hannah MathersDr. Todd MervoshDr. Mike MickelbartDr. Joe NealDr. Mike RedingDr. Rich ReganDr. Andy SenesacDr. Brian TraderDr. Paul WadeDr. Cheryl WilenDr. Dave WilliamsPhoto by C. Palmer

Herbicides for Crop Safety Testing

Product Number of Crops Number of TrialsBroadstar 0.25G V1604 61 177Echelon (F6875) G 27 38Echelon (F6875) EC 7 8EXC3898 48 138Freehand G 120 328Snapshot 40 54Sulfosulfuron 73 111Tower EC 79 192V-10162 0.5G 48 145

Outcomes• EPA Registration received in 2008 based on 2007

research activities – Freehand G (dimethenamid-p + pendimethalin)– Tower EC (dimethenamid-p)

• Formulation replaced in 2009 partially based on IR-4 crop safety data– BroadStar VC1604 (flumioxazin)

• Further Development not recommended– EXC3898 (mesotrione + prodiamine + S-metolachlor)

• Future submissions planned– Echelon (sulfentrazone + prodiamine) aka F6825– Snapshot (trifluralin + isoxaben)– Sulfosulfuron– V-10142 G (imazasulfuron)

Photo by C. Palmer

Early Post Emergence Efficacy

Early Post Emergence Efficacy• Application Timing

– Stage 1: Pre-emergent treatments– Stage 2: Early post-emergent treatments when weeds

at cotyledon to 1 leaf– Stage 3: Post-emergent treatments when weeds at 2

to 4 leaves• Weeds: Bittercress, Oxalis & Spurge• Products

– BroadStar– Casoron– EXC3898– Freehand– Gallery

– HGH-63– Pendulum 3.3EC– Sulfosulfuron– Tower EC– V-10142 0.5G

Early Post Emergence Participating Researchers

Dr. Rick BoydstonDr. Charles GilliamDr. Joe NealDr. Rich ReganDr. Andy SenesacDr. Cheryl Wilen

Photo by C. Palmer

Compilation Rating Scale• Converted researcher ratings to:

– 0 = No Control = <60%– 1 = Poor Control = between 60 and 70%– 2 = Fair Control = between 70% and 80%– 3 = Good Control = between 80% and 90%– 4 = Excellent Control = >90%

• For tables on following slides provided best possible rating across time, production site

Pre and Early Post Treatment for BittercressCompilation across Trials

Treatment (Product per acre) # Pre Cotyl. to 1‐leaf 2 to 4‐ leafBroadstar (75 lb) 1 4 0 0Broadstar (150 lb) 1 4 2 1Broadstar VC1604 (75 lb) 9 1.0 0.2 0.0Broadstar VC1604 (150 lb) 9 2.1 0.7 0.6Broadstar VC1604 (300 lb) 1 4 1 2Casoron 4G (25 lb) 2 0.0 0.0 0.5Casoron 4G (50 lb) 2 0.0 0.0 0.5Gallery 3 0.0 4.0 3.3HGH‐63 2G (50 lb) 3 0.0 0.7 0.0HGH‐63 2G (100 lb) 2 0.0 0.0 0.0Sulfosulfuron (0.035 lb ai) 3 2.0 3.0 1.7Sulfosulfuron (0.094 lb ai) 3 2.0 3.7 2.0Tower (21 fl oz) 2 ‐ 0.0 0.5Tower (32 fl oz) 2 ‐ 0.0 0.5V‐10142 0.5G (75 lb) 10 2.75 2.2 2.4V‐10142 0.5G (150 lb) 10 2.75 3.1 2.4V‐10142 0.5G (300 lb) 1 4 2 3

Pre and Early Post Treatment for OxalisCompilation across Trials

Treatment (Product per acre) # Pre Cotyl. to 1‐leaf 2 to 4‐ leafBroadstar (75 lb) 1 4 0 0Broadstar (150 lb) 1 4 0 2Broadstar VC1604 (75 lb) 6 2.5 0.0 0.7Broadstar VC1604 (150 lb) 6 2.7 0.3 0.8Broadstar VC1604 (300 lb) 1 1 0 3Casoron 4G (25 lb) 1 0 0 2Casoron 4G (50 lb) 1 0 0 3HGH‐63 2G (50 lb) 3 0.0 3.0 0.0Sulfosulfuron (0.035 lb ai) 1 2 2 3Sulfosulfuron (0.094 lb ai) 1 2 2 3V‐10142 0.5G (75 lb) 8 3.0 1.9 1.3V‐10142 0.5G (150 lb) 8 3.4 2.4 1.9V‐10142 0.5G (300 lb) 1 4 3 0

Pre and Early Post Treatment for SpurgeTreatment (Product per acre) # Pre Cotyl. to 1‐leaf 2 to 4‐ leafBroadstar (75 lb) 1 4 0 0Broadstar (150 lb) 1 3 0 0Broadstar VC1604 (75 lb) 6 1.3 0.0 0.0Broadstar VC1604 (150 lb) 7 1.6 1.0 0.3Broadstar VC1604 (300 lb) 4 2.0 2.5 1.0Casoron 4G (25 lb) 3 0.0 0.0 0.0Casoron 4G (50 lb) 3 0.0 0.0 0.0Freehand (200 lb) 3 4.0 2.3 0.3Freehand (400 lb) 3 4.0 3.3 1.0HGH‐63 2G (50 lb) 1 0 1 3HGH‐63 2G (100 lb) 2 0.0 0.0 0.0Pendulum 3.3EC  (2 lb ai) 3 4 4.0 2.7Pendulum 3.3EC  (4 lb ai) 3 4 4.0 3.3Sulfosulfuron (0.035 lb ai) 3 0 2.7 1.3Sulfosulfuron (0.094 lb ai) 3 0 2.3 1.7Tower (21 fl oz) 3 4 3.0 0.0Tower (32 fl oz) 3 4 3.3 1.3V‐10142 0.5G (75 lb) 5 1.2 1.0 1.0V‐10142 0.5G (150 lb) 5 2.6 2.0 1.2V‐10142 0.5G (300 lb) 1 4 2 2

Summary• Bittercress: Gallery exhibited good control at cotyledon to

1 leaf and 2- to 4- leaf stages; sulfosulfuron at both rates and V-10142 at 150 lb per acre also provided good control.

• Oxalis: Broadstar 0.25G VC1604 and V-10142 0.5G provided good pre-emergent control, but only HGH-63 controlled this weed at the cotyledon to 1-leaf stage.

• Spurge: Freehand, Pendulum 3.3EC and Tower exhibited good pre and early post emergent control, but only Pendulum provided sufficiently consistent good control at the 2- to 4- leaf stage.

Future Research• Continue Herbicide Crop Safety Screening

– Biathalon, Broadstar 0.25G VC1604, Freehand, Gallery, Snapshot, sulfosulfuron, and Tower EC

– Field Container– In Ground for Cut Flowers

• Early Post Emergence– Continue Oxalis screening– Eclipta, Phyllanthus, Canada thistle, velvet

leaf, western salsify

Acknowledgements• Regional Field Coordinators

– Edith Lurvey– Charlie Meister– Satoru Miyazaki– Paul Schwartz– Becky Sisco

• All the researchers who participated

Thank you !

Photo by C. Palmer