WEED CONTROL IN SUGARBEETS

Dr. Alan Dexter - Sugarbeet Weed Control Specialist

Main problem with tank-mixing pesticides or pesticides and liquid fertilizer is the failure of components to remain uniformly dispersed.

Causes

  1. Inadequate agitation. Mechanical and hydraulic jet or sparger agitation is better than by-pass agitation.
  2. Insufficient spray volume. Suspensions require 1-2 gallons of spray carrier per pound of product.
  3. Excessive spray volume. Some pesticides settle out if diluted too much. Example is Betanal.
  4. Lack of a stable emulsifier.

Preventative measures

  1. Never put a pesticide in an empty tank.
  2. Mix pesticides with water before adding to the spray tank.
  3. Add wettable powders to spray tank before emulsifiable concentrates.
  4. Use special fertilizer formulations of emulsifiable concentrates if available.
  5. Add a compatibility agent such as Compex if needed.
  6. Add the compatibility agent before the pesticides.

Check compatibility in quart jars before filling a spray tank.

Testing procedure

  1. Determine the spray volume to be used per acre.
  2. Determine the rate of the pesticides to be applied in a given volume of spray solution.
  3. Convert quarts or pounds per acre of pesticide to amounts per pint of spray solution.
  4. Place 1 pint of carrier in each of two quart jars.
  5. Add 1/3 teaspoon of compatibility agent (3 pints per 100 gallons) to one jar and mark "A", adjuvant added. Mark the other jar "B".
  6. Add the proper amount of each pesticide to each jar and shake.
  7. Observe the mixtures at once and again after 30 minutes.

Comparing jar "B" with jar "A" will determine the value of adding a compatibility agent. If materials remain suspended or if they are easily resuspended, mixing is possible with good agitation. If they separate, precipitate, or form "gunk", check jar "A" to see if adding a compatibility agent solved the problem. If so, repeat thetest using varying amounts of compatibility agent to determine the optimum amount needed.
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1 pint = 473 milliliters
1 pound = 454 grams
1 pound/25 gallons = 2.2 grams/pint
1 quart/25 gallons = 4.7 milliliters/pint

If gram scales and milliliter measures are not available, then approximations can be made with measuring spoons.

1 teaspoon = 5 milliliters
1 level teaspoon = 2 to 3 grams

1 quart of emulsifiable concentrate or 1 pound of wettable powder per 25 gallons of water would be appoximately 1 level teaspoon per pint.

Are spray tank mixes legal?

Agricultural pesticides must be registered and the safety and residues of the pesticides must be established by the Federal Environmental Protection Agency (EPA). In the past, obtaining clearance for the use of mixtures of previously registered pesticides was not difficult. Now a set of data on all facets of the spray tank mixture is required as though the mixture was a completely new pesticide.

Supposedly, if the label does not state how the pesticide can be applied in combination with fertilizer, then such a combination should not be used. However, farmers can still apply on-the-farm mixtures if the company does not register the combination. The user must assume the responsibility that food and feed products are free of illegal residues.

Key Information Found on a Label

  1. name of manufacturer
  2. name of product
  3. what the product does
  4. ingredients
  5. pounds per gallon or percent active ingredient
  6. directions for use
    a) crop precautions
    b) how to apply material
    c) pests controlled
  7. storage precautions
  8. personal precautions
  9. recommendations
    a) for specific pests
    b) crops
    c) timing of application
    d) dosage
    e) special instructions or warnings

Relative Performance of Herbicides Cleared for Use on Sugarbeets

wild oats








_____________
wild mustard








_____________
Setaria sp.pigeongrass or foxtails






_____________
redroot pigweed








_____________
wild buckwheat








_____________
common lambsquarters







_____________
smartweed
ppi

_____________
pre
_____________
post



_____________
ppi

_____________
pre
_____________
post



_____________
ppi

_____________
pre
_____________
post



_____________
ppi

_____________
pre
_____________
post



_____________
ppi

_____________
pre
_____________
post



___________
ppi

_____________
pre
_____________
post



_____________
ppi

_____________
pre
_____________
post
Avadex (diallate) - good to fair
Eptam (EPTC) - fair to good
Ro-Neet (cycloate) - fair to good________________
TCA - poor to fair
Pyramin (pyrazon) - poor______________________
Carbyne (barban) - good to fair
Dowpon (dalapon) - fair to poor
Betanal (phenmedipham) - poor to fair
H-273 (endothall) - poor
Pyramin (pyrazon) - poor______________________
Eptam (EPTC) - poor
Ro-Neet (cycloate) - poor
Avadex (diallate) - poor_______________________
TCA - poor
Pyramin (pyrazon) - good to poor________________
Betanal (phenmedipham) - good
Pyramin (pyrazon) - good to fair
H-273 (endothall) - poor to fair
Dowpon (dalapon) - poor
Carbyne (barban) - poor______________________
Eptam (EPTC) - good
Ro-Neet (cycloate) - good
Avadex (diallate) - poor to fair__________________
TCA - good
Pyramin (pyrazon) - poor______________________
Dowpon (dalapon) - good
Betanal (phenmedipham) - fair to good
H-273 (endothall) - poor
Carbyne (barban) - poor
Pyramin (pyrazon) - poor______________________
Eptam (EPTC) - good to fair
Ro-Neet (cycloate) - good to fair
Avadex (diallate) - poor_______________________
Pyramin (pyrazon) - poor to good
TCA - poor________________________________
Pyramin (pyrazon) - good to fair
H-273 (endothall) - poor to fair
Betanal (phenmedipham) - poor
Dowpon (dalapon) - poor
Carbyne (barban) - poor_______________________
Eptam (EPTC) - poor
Ro-Neet (cycloate) - poor
Avadex (diallate) - poor_______________________
Pyramin (pyrazon) - good to poor
TCA - poor________________________________
H-273 (endothall) - good
Betanal (phenmedipham) - good
Pyramin (pyrazon) - good to fair
Carbyne (barban) - poor to fair
Dowpon (dalapon) - poor_____________________
Eptam (EPTC) - good to fair
Ro-Neet (cycloate) - good to fair
Avadex (diallate) - poor_______________________
Pyramin (pyrazon) - good to poor
TCA - poor________________________________
Betanal (phenmedipham) - good
Pyramin (pyrazon) - good to fair
H-273 (endothall) - poor to fair
Dowpon (dalapon) - poor
Carbyne (barban) - poor______________________
Eptam (EPTC) - poor
Ro-Neet (cycloate) - poor
Avadex (diallate) - poor_______________________
Pyramin (pyrazon) - good to poor
TCA - poor________________________________
H-273 (endothall) - good
Pyramin (pyrazon) - good to fair
Betanal (phenmedipham) - fair
Carbyne (barban) - poor
Dowpon (dalapon) - poor

Approximate ranking of safety to sugarbeets


Injury least likely
|
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injury more likely
treatment____________________________________________
Carbyne (barban) post
Avadex (diallate) ppi
Ro-Neet (cycloate) ppi
TCA pre
Pyramin (pyrazon) pre or post
Ro-Neet + Avadex (ppi)
H-273 (endothall) post
Dowpon (dalapon) post
Eptam (EPTC) ppi
Pyramin Plus (pyrazon + dalapon) post
Betanal (phenmedipham) post
Eptam + Avadex ppi
Eptam + TCA ppi
Ro-Neet (ppi) followed by Betanal or Pyramin Plus (post)
Ro-Neet + Avadex (ppi) followed by Betanal or Pyramin Plus (post)
Eptam (ppi) or TCA (pre) followed by Betanal or Pyramin Plus(post)
Eptam + Avadex (ppi) or TCA + Avadex (ppi) followed by Betanal or Pyramin Plus (post)
Eptam + TCA (ppi) followed by Betanal or Pyramin Plus (post)

Herbicides applied to hand weeded sugarbeets, Fargo, 1970
Herbicides applied to hand weeded sugarbeets, Fargo, 1971


1971 Sugarbeet Research and Extension Reports. Volume 2, pages 62 - 66.


Red River Trade Corridor
Questions/Comments