ISSUE #554

554 - Maximizing Weed Control in Roundup Ready Sugarbeet

6-2-11

Weed control has been made much more convenient and effective using herbicides containing glyphosate. Well over 50 herbicides containing glyphosate are registered for use in 2011. These products have 6 different levels of acid equivalent and vary widely in content of non-ionic surfactant. A brochure prepared with the assistance of Dr. Jeff Stachler, NDSU/UM Extension Sugarbeet Weed Specialist, summarizes the characteristics of each herbicide. It is available from your agriculturist.

Avoid Competition with Proper Timing

Weed Pressure

Recommended Timing
Light 2-4 Leaf Beets
Moderate 2 Leaf Beets
Heavy Cotyledon - 2 Leaf Beets

554

Roundup Ready® Rate Selection

One rate of glyphosate does not fit all situations. Select rates based on a number of factors including the following considerations:

  • Weed species present
  • Environmental conditions
  • Weed growth stage
  • Possible weed tolerance or resistance to glyphosate

Maximize Glyphosate Rate Effectiveness

SituationRate (4.5 lb/Gal. Acid Equiv)
Small weeds, very favorable environment 22 oz/acre
Less favorable environment or larger weeds 28 oz/acre
Unfavorable environment, very large weeds, hard to control weed species, suspected tolerance to Glyphosate 32 oz/acre

Timing the Second Application

  • The label states it must be 10 days or more after the first application
  • Determine if sufficient weeds have emerged
  • Determine when weed size, species and density justify spraying
  • Most second applications will be from 14 to 28 days after the initial application

Tips on Maximizing Weed Control With Roundup Ready®

  • Best control is from 10 a.m. to 4 p.m.
  • Add 8.5 to 17 lbs. of AMS per 100 gallons of spray solution
  • Control is often better with lower volumes, about 10 gpa
  • Rain within 6 hours may reduce weed control
  • Avoid spraying with dust on plants
  • Avoid spraying with dew on plants
  • Cool weather slows activity and time needed for control
  • Frost before application will reduce control
  • Drought slows weed growth, reduces activity
  • Air temperature over 85°F during application can reduce weed control
  • Don't spray after sunset-weed control can be reduced

When to Tank Mix Stinger and Glyphosate

  • For volunteer soybeans
  • For glyphosate resistant Common Ragweed
  • For Wild Buckwheat
  • For Biennial Wormwood

Know Your Acid Equivalents

Over 50 Glyphosate formulations are available in 2011

Be sure you use correct rates.

Be Careful

Seed color alone is no guarantee a variety is conventional or Roundup Ready®. Ask your neighbor.