To Mix or Not to Mix: That is the Question? (Tank-mixing Herbicides and Fungicides)

1. To Mix or Not to Mix: That is the Question?(Tank-mixing Herbicides and Fungicides) Eric P. Prostko Extension Weed Specialist Department of Crop & Soil Sciences University of Georgia

2. Why tank-mix agrochemicals? • Advantages • Increase spectrum of control • decrease time and labor cost • less vine damage • decrease soil compaction • Disadvantages • Reduced control • Increased crop injury • Physical incompatibility • different spray volumes/nozzle types • adjuvant recommendations

3. Spray Volumes and Nozzle Tips • What is the best water volume to use for …….. • fungicides • herbicides • What is the best nozzle to use for…. • fungicides • herbicides

4. Nozzle Tips

5. What happens when you mix chemicals? • additive * 1 + 1 = 2 • synergistic * 1 + 1 = 3 • antagonistic * 1 + 1 = 1 or less

6. Antagonism Gramoxone Max 10 ozs/A + Storm (1.5 pt/A) Gramoxone Max 8 ozs/A 1 DAT

7. What do the labels tell us? • In most cases, not very much • Unclear, vague, and confusing • Trial and error • Has someone else done it?

8. Cadre Tank-Mixes

9. Headline PropiMax* EC Nichino America ARTISAN MONCUT 70DF ECHO® 720 AG

10. What have we learned? • Generally no major problems but….. • Impossible to test under all environmental scenarios • There are some specific problems

11. Annual Grasses and Select(Jordan et al. 2003. Peanut Science 30:1-7) • More of a problem when applied in 25 GPA than if applied in 10 GPA • % of comparisons where control was reduced • Kocide, ManKocide, Tenn-Cop = 80% • 7-75% reductions in control • Bravo and others = 69% • 2-60% reductions in control • Abound = 60% • 5-13% reductions in control • Folicur and Tilt did not reduce efficacy

12. Texas panicum control with Cadre/fungicide tank-mixes, 2002 (67 DAT) . LSD 0.05 = 20 LSD 0.10 = 17

13. A New Publication(For more specifics) • Tank Mixing Chemicals Applied to Peanut Crops: Are the chemicals compatible? • June 2004 • Regional publication housed at NCSU (AGW-653) • Available on-line at: http://www.peanut.ncsu.edu/ag653.pdf

14. New POST Labels for 2005 • Strongarm • 24c label in GA • No fungicide tank-mix information • Cobra • Label says do not tank-mix

15. Before spraying….. • Read label • Water volume compatible for both • Nozzle type • Contact county agent • Check for physical compatibility • Jar test

16. Mixing Order • some water (1/2) + agitation • water soluble packets • wettable powder in slurry • DF or WDG • liquid flowables • EC • NIS/COC/AMS/UAN • Remaining water (AMS then glyphosate)

17. Two-Jar Test • 1 pt of carrier (water) to each of 2 qt jars • ¼ teaspoon of compatibility agent to 1 jar • Blendex (Helena) • Mix (Drexel) • Unite (Loveland) • To each jar, add required amount of pesticide in order suggested previously. Shake well after each addition. • After all have been added, shake for 15 seconds and let stand for 30 minutes

18. Other issues • Adjuvants • How is fungicide formulated? • How bad are the weeds? • What about ….. • insecticides • fertilizer • 3 or 4 way mixes

19. www.gaweed.com