Bare Ground Weed Control J. Ferrell Extension Weed Specialist

Why do you need bare ground? • Substations – Reduces fire potential – Reduces habitat cover

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Why do you need bare ground? • Guard rails – Pavement longevity (veg. promotes cracks, freeze/thaw cycle, damaged pavement) – Reduce fire potential – Trash accumulation – Appearance – Worker safety http://www.gardenstatehwy.com/images/sce/Guardra il-03.gif

Do you want total veg. control here?

What makes a good veg. control product? • Broad spectrum – grass and broadleaf • Persistence – The longer it lasts the better • Lateral movement is bad

Lateral movement is bad

Lateral movement is bad

Lateral movement is bad

What are the options?

Oust • Sulfometuron • Rate 0.25 to 3 oz – At low rates it stops grass growth.

• Spectrum – excellent on grass, good on some broadleaf weeds • Pre and Post activity • Long persistence, little to moderate lateral movement • Rate dictates suppression or bare ground

Oust 3oz – 2 months • Will need glyphosate for initial burndown.

Photo: Courtesy of Mitch Blair, University of Kentucky

Payload • Flumioxazin • Rate 8 to 12 oz/A • Spectrum – fair to good on broadleaf (small seeded), very weak on grass, sedges, and perennials. • Pre and Post activity (mostly Pre) • Moderate persistence, little lateral movement

Payload 10-12 oz – 6 months

• Lacks grass control • No movement

• Needs glyphosate for burndown • Needs partner Photos: Courtesy of Mitch Blair, Univ. of Kentucky

Karmex • Diuron • Rate 5 to 15 lb/A • Spectrum – good on broadleaf and grass; weak on perennials • Pre and Post activity (mostly Pre) • Long persistence, little to moderate lateral movement • Rate dictates bare ground or suppression

Karmex 12 lb – 6 months • No movement • Good on grass and broadleaf • Lower rates ideal for seasonal control

Photo: Courtesy of Mitch Blair, University of Kentucky

Krovar or Hyvar • Hyvar (bromacil)– Krovar (bromacil+diuron) • Rate Hyvar 3 to 15 lb/A • Spectrum – good on broadleaf and grass; good on perennials and woodys • Pre and Post activity (mostly Pre) • Lateral movement is likely • Very long persistence, bare ground only

Krovar 10 lb – 6 months • Lateral movement? • Good, but not perfect

Photo: Courtesy of Mitch Blair, University of Kentucky

Pramitol • Prometon • Rate 5 to 10 gal/A • Spectrum – good on broadleaf and grass; controls some weeds for years, but likely to miss others • Mostly Pre • Lateral movement is possible • Very long persistence, bare ground sites only

Esplanade • Indaziflam • Rate 16-24 oz/A • Spectrum – Excellent on grass, certain broadleaf; weak on perennials • Pre activity • Long persistence, little to moderate lateral movement • Rate dictates duration of bare ground

Oust + Karmex – 200 days

Esplanade – 200 days

Journey • • • • • •

Imazapic + glyphosate Rate: 1% solution Good for extended suppression Excellent on grasses and sedges Lateral movement is highly unlikely For larger weeds, add more glyphosate

Arsenal • Imazapyr • Rate: 16 to 64 oz • Spectrum – Excellent initial control of grass, broadleaf, and woody species. • Excellent residual on some species, totally misses others (hairy indigo, others) • Very long persistence • Lateral movement is possible at higher rates, root uptake by trees is possible.

Sahara • • • • • •

Imazapyr + diuron Rate: 6 to 13 lb/A Good mixture Very long persistence and broad spectrum Lateral movement possible Total, long-term bare ground only

Lateral movement is bad

“Hard” products • Total veg. control and long residual • These products are more risky • Hyvar, Krovar, Sahara, Pramitol, maybe Oust

“Soft” products • Short-term control or suppression • Public mistakes are not as likely • Glyphosate, Journey, Karmex, Payload

Conclusion • Do you need full vegetation control, or suppression? • Is lateral movement a concern? • There is no perfect herbicide for all situations – Be prepared to mix several products to meet you needs.