QUALITY ADJUVANTS

1. QUALITY ADJUVANTS Importance & Economics Barriers of Entry Mode of Action Quality

2. Importance & Economics • What value does the adjuvant bring? Without adjuvants many herbicides would not perform!

3. Importance & Economics Dr. Jerry Green - DuPont - Program Leader for Adjuvants “Adjuvants are helping shift the herbicide market from preventive soil applications at high rates to curative applications applied directly to the weeds at low rates.” • post applied treatments are increasing • about 54% of corn, 79% of soybeans and 90% of wheat receive a post herbicide application

4. Importance & Economics

5. Importance & Economics

6. QUALITY ADJUVANTS An adjuvant is…or could be... surfactant crop oil methylated seed oil fertilizer antifoamer defoamer compatibility agent Adjuvant - a material added to a tank mix to aid or modify the action of an agrichemical, or the physical characteristics of the mixture. “All surfactants are adjuvants, but not all adjuvants are surfactants…”

7. QUALITY ADJUVANTS Importance & Economics Barriers of Entry Mode of Action Quality

8. Barriers of Entry • Multiple Barriers of Entry • Leaf angle • Leaf hairs or pubescence • Leaf surface or cuticle • Cell wall or membrane The herbicide must pass through these barriers and translocate to be effective.

9. Barriers of Entry Leaf angle Common sense, but often overlooked. Grasses are smaller target versus broadleaves.

10. Barriers of Entry • Leaf hairs (pubescence) Absorption dependent on good leaf-to-spray contact. Some weeds are very hairy...microscopically.

11. Barriers of Entry • Leaf surface or cuticle Made up of many parts; waxes - oil soluble or lipophilic, cutin - water soluble or hydophilic, pectin - water soluble pathways for entry.

12. Barriers of Entry • Cell Wall or membrane Ammonium ions drive ion trapping.

13. Barriers of Entry • Translocation Different herbicides translocate differently.

14. QUALITY ADJUVANTS Importance & Economics Barriers of Entry Mode of Action Quality

15. Mode of Action • How does the adjuvant help penetrate these barriers? It depends on the adjuvant used... • Activator Adjuvants • Nonionics surfactants • Crop oil concentrates • Methylated seed oils • Nitrogen fertilizers

16. Mode of Action • Nonionic surfactants affect • spray solution • the surface of plant tissue • the cuticle surface • the cuticle layers Facilitates wetting, more uniform spreading, dispersing,solubilizing, and emulsifying for enhanced herbicide uptake. Decreases surface tension, slows drying time, increases penetration.

17. Mode of Action • Nonionic surfactants • Combined water-loving and oil-loving properties...referred to as HLB Value • Hydrophilic-lipophilic balance • HLB Value is very important • 1 = oil loving...20 = water loving • The higher the HLB Value, the better the effectiveness with most water soluble herbicides.

18. Mode of Action • Crop oil concentrates • petroleum based with surfactants/emulsifiers • 80/20 or 83/17 (COC + surfactants/emulsifiers) Both the oil and type of surfactants enhance activity. • oil facilitates the penetration of the cuticle • emulsifier/surfactant allows oil to mix with water & assist in uptake of herbicide • commonly used when stress conditions exist

19. Mode of Action • Methylated Seed Oils • free fatty acids derived from soybean, corn, sunflower oils then reacted with methanol yielding methyl esters The most active activator adjuvants. performs very well on large or drought stressed weeds

20. Mode of Action • Methylated Seed Oils • MSOs are better spreaders versus COCs • high boiling point allows less evaporation - increasing the absorption • remains an oily liquid on the leaf - doesn’t dry to a salt crystal • similar in structure to cuticular waxes - causing “swelling” of waxes - increasing penetration

21. Mode of Action

22. Mode of Action • Nitrogen fertilizers Namely AMS or UAN • recently of greater interest • used alone or often with other adjuvants • ammonium and sulfate ions are key Often specific with weed/herbicide or environmental conditions. Relative analysis: Ammonium Nitrate Urea Sulfate AMS = 21 0 0 24 UAN = 7 7 14 0 Rule of thumb…1 # of AMS ~1 qt of UAN for NH4 Little if any sulfate benefits with UAN

23. Mode of Action • Fertilizers • AMS • solves hard water antagonism • Ca, Mg, Zn, Na, Al or Fe • assists in uptake via “ion trapping”

24. QUALITY ADJUVANTS Importance & Economics Barriers of Entry Mode of Action Quality

25. Quality • Quality Rating System Developed to overcome confusion and communicate the important criteria of a high quality adjuvant. Quality Rating System was developed in consultation with manufacturers of pesticides and adjuvant suppliers. Dr. Richard K. Zollinger-NDSU-Ext. Weed Control “Yes, there is a difference among adjuvants - All adjuvants are NOT created equal.”

26. Quality • Nonionic Terms important criteria for selecting a high quality surfactant virgin ingredients active ingredients HLB Value surfactant load antifoam index Should be stated on the label ! Puts more validity into the marketplace. Educates the buyer.

27. Quality • COC/MSO Terms (important criteria for selecting a high quality surfactant - in addition to the nonionic terms) oil load oil type viscosity paraffinic hydrocarbon unsulphonated residue Should be stated on the label ! Puts more validity into the marketplace. Educates the buyer.

28. CPDA Certified • Chemical Producers & Distributors Association • Labeling and Performance Standards for Spray Adjuvants • Look for some changes in 2001. • Adopted July 16, 2000. • Voluntary Functionality claims ASTM Standards CFR 40, 180.1001 DOT Packaging Signal Words Acute toxicity % Surfactant Load Oil Type Description Unsulphonated Oil Residue Good Manufacturing and Stewardship Practices Costs to Certify

29. QUALITY ADJUVANTS Importance & Economics Barriers of Entry Mode of Action Quality QUESTIONS AND ANSWERS