![Page 1: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/1.jpg)
Herbicidal weed controlDr. James Altland
Oregon State University
![Page 2: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/2.jpg)
Total weed management programEffective weed control
Sanitation•Weed seed
•Weeds in non-cropland areas
Herbicide management•Maintain chemical barrier
![Page 3: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/3.jpg)
Weed control reality
• Weed seeds are present in soil
• You cannot eliminate all weed seed– Even fumigation with MeBr is only temporary
relief
• Sanitation and management practices should discourage weeds from establishing
![Page 4: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/4.jpg)
Redroot pigweed• Plants produce up to 100,000 seed
– 13,860 with no fertilizer– Over 34,600 when fertilized
• Seed can be wind dispersed– Small size
• Seed survive for more than 30 years– Soil surface or buried
![Page 5: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/5.jpg)
Weeds
• Plants that are successful colonizing disturbed, but potentially productive, sites and maintaining their abundance with repeated disturbance.
Liebman et al.
![Page 6: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/6.jpg)
![Page 7: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/7.jpg)
Landscape weed control
• Sanitation
• Mulches
• Herbicides
![Page 8: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/8.jpg)
Herbicides in landscapes
• Preemergence herbicides– Apply to weed free soil– Apply prior to weed emergence– Apply uniformly and do not disrupt
• Postemergence herbicides– Select the correct type– Apply thorough coverage
![Page 9: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/9.jpg)
Preemergence herbicides
• Most seed germinate in the top 1 inch of soil.
• Herbicide placement should occur where seeds will germinate and begin growing.
• Application of herbicide followed by incorporation with water is necessary for proper placement.
![Page 10: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/10.jpg)
Preemergence herbicides
• Will not kill weeds present at time of application
• Even small weeds have roots large enough to escape effect of pre herbicides.
![Page 11: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/11.jpg)
![Page 12: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/12.jpg)
Preemergence herbicides
• Do not prevent seed from germinating
• Do not kill dormant seeds!!!!
• Typical herbicidal activity– Hypocotyl and epicotyl emerge from seed– Grows through chemical barrier– Herbicide is absorbed and weed is killed or
stunted.
![Page 13: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/13.jpg)
Weed species controlled (pre-em)
• Broadleaf-active herbicides– Goal– Princep– Gallery
• These herbicides provide moderate to poor control of grasses, especially at lower rates.
![Page 14: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/14.jpg)
Weed species controlled (pre-em)
• Grass-active herbicides– Surflan, Pendulum, Treflan, Factor– Ronstar– Pennant
• These products provide effective control of grasses and some “small-seeded” broadleafs
![Page 15: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/15.jpg)
Weed species controlled (pre-em)
• Broad-spectrum control• Tank mix a grass-active herbicide with a
broadleaf-active herbicide– Gallery + Pendulum– Goal + Factor– Princep + Surflan
![Page 16: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/16.jpg)
Herbicide timing
• Herbicides must be applied prior to weed emergence.
• Weeds present at application will continue growing.
![Page 17: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/17.jpg)
![Page 18: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/18.jpg)
Maintain the chemical barrier
• Incorporate the herbicide
• Reduce unnecessary traffic
• Reduce excessive irrigation
![Page 19: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/19.jpg)
Reduce traffic
![Page 20: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/20.jpg)
Incorporate the herbicide
• Most abused aspect of weed control
• Incorporate immediately after application– Herbicides degrade on soil surface
• Incorporate with irrigation if possible
• Do NOT incorporate with drip irrigation!!!
![Page 21: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/21.jpg)
![Page 22: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/22.jpg)
![Page 23: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/23.jpg)
Uniformity of application
• Mostly a problem with granular applications
• Research shows that even under ideal conditions, amount applied can be from ½ to 2 times the intended rate.
• Take steps to improve uniformity
![Page 24: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/24.jpg)
![Page 25: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/25.jpg)
Uniformity of application
• Apply a single application in multiple passes.
• Takes more time, but dramatically improves uniformity.
![Page 26: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/26.jpg)
Improper calibration
• Herbicides control weeds at specific rates– Low rates provide poor control– High rates may cause injury
• If calibration is not accurate, rates will also be wrong
![Page 27: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/27.jpg)
![Page 28: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/28.jpg)
Problems with calibration
• Check for unequal distribution from nozzles– Nozzles must all be the same
• Unless manufacturer specifies otherwise
– Nozzles must be clean and working properly
• Calibrate equipment often– If using computer control systems, verify often.
![Page 29: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/29.jpg)
Preemergence herbicides
• If applying to bark– Apply to moist bark
• Pre-herbicides applied to dry bark reduces efficacy– Dry bark adsorbs the herbicide tightly– May not be released with subsequent irrigation– Herbicide is rendered ineffective
![Page 30: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/30.jpg)
Postemergence herbicides
• Select the right type of herbicide– Contact– Translocated
• Apply thorough coverage
• Ensure adequate uptake and movement
![Page 31: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/31.jpg)
Contact herbicides
• Burns only foliage that is contacted.
• Good for control of annual weeds.
• Will not control roots of perennial weeds.
![Page 32: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/32.jpg)
Postemergence herbicides
• Contact– Finale (poorly translocated)– Gramoxone– Scythe (pelargonic acid, soft pesticide)– Diquat– Acetic acid
![Page 33: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/33.jpg)
Contact herbicides
• Require thorough coverage for complete control
• Best when used on small, recently germinated weeds.
• Not effective against established perennials.
![Page 34: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/34.jpg)
![Page 35: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/35.jpg)
Translocated herbicides
• Absorbed by foliage and other green tissue
• Moved throughout plant along with photosynthates
• Moved to growing points
![Page 36: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/36.jpg)
Postemergence herbicides
• Translocated– Moved throughout the plant to control roots and
shoots• Roundup – all vegetation• Vantage – grasses only• Fusilade – grasses only• Envoy – grasses only• Manage - Nutsedge
![Page 37: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/37.jpg)
Translocated herbicides
• Require living, functioning plants.
• Environmental conditions that favor plant growth also improve effectiveness– High light– adequate soil moisture– moderate temperatures
![Page 38: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/38.jpg)
Translocated herbicides
• Coverage is extremely important for controlling perennial weeds– Convolvulus arvensis– Roots grow to a depth of 30 feet.
![Page 39: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/39.jpg)
Translocated herbicides
• Ideal for killing perennial weeds• Best when used for spot spraying• Will injure ornamental crops if contact is made
![Page 40: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/40.jpg)
Which type?
• Contact herbicides– Faster action– Safer around ornamentals– Will not kill roots (perennials)
• Translocated herbicides– Slower action– More effective across all weed types– Greater potential injury to ornamentals
![Page 41: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/41.jpg)
Postemergence herbicides
• Foliar uptake dependent on 2 factors:
• Foliar retention• Ability of the herbicide to adhere to the leaf surface.
• Cuticle penetration
![Page 42: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/42.jpg)
Foliar retention
• Spray applications– Water will bead on waxy cuticle– Reduce water tension with adjuvants
![Page 43: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/43.jpg)
![Page 44: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/44.jpg)
Cuticle penetration
• Environmental factors that improve uptake– Any condition that causes the cuticle to hydrate
• High humidity, warm temps, adequate soil moisture
– Conditions that cause plants to develop thin cuticles
• Low light, high humidity, warm temps, adequate soil moisture
– Conditions that favor opening of stomata.
![Page 45: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/45.jpg)
Water as a carrier
• Hard water– High Mg and Ca– Herbicides formulated as salts dissociate in water
– Mg++ or Ca++ can rebind to the glyphosate anion and cause it to precipitate out of solution.
• Reduce the effects of hard water– Add ammonium sulfate or acid– Reduce spray volume
![Page 46: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/46.jpg)
![Page 47: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/47.jpg)
![Page 48: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/48.jpg)
‘Soft’ herbicides
• Acids– Many naturally occurring acids are bottled and
sold as herbicides– All are contact herbicides
• Burn plants to the ground, no control of root system
– Work best on warm sunny days• Temps greater than 70 F (21 C)
![Page 49: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/49.jpg)
Soft herbicides
• Acids– Acetic acid is vinegar
• Ecoclear
– Pelargonic acid• Scythe
– N-phuric acid
![Page 50: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/50.jpg)
Acetic acid
• Vinegar contains about 5% acetic acid• Contact herbicide• Excellent on small weeds
– Thorough coverage is essential.• Species specific• Requires a surfactant • Will burn ornamentals as well.
![Page 51: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/51.jpg)
![Page 52: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/52.jpg)
![Page 53: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/53.jpg)
![Page 54: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/54.jpg)
Natural herbicides
• Corn gluten meal– Mostly fertilizes weeds
– Weeds grow better.
• Can be effective in turf.– Turf fertilizer– More vigorous turf, fewer weeds.
![Page 55: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/55.jpg)
![Page 56: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/56.jpg)
Soft herbicides
• Alternative to synthetic products
• They have a niche use
• Generally not as effective as synthetic counterparts
![Page 57: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/57.jpg)
Summary
• Preemergence herbicides– Apply to clean, weed-free soil– Maintain the integrity of the chemical barrier
• Postemergence herbicides– Select the right product/type– Thorough coverage
![Page 58: Oregon State University Herbicidal weed controloregonstate.edu/dept/nursery-weeds/presentations/land_herb.pdf · Acetic acid • Vinegar contains about 5% acetic acid • Contact](https://reader031.vdocuments.us/reader031/viewer/2022020120/5b2455e37f8b9a2e1f8b4647/html5/thumbnails/58.jpg)
Website
• http://oregonstate.edu/dept/nursery-weeds/