Water Volume Tractor Speed and Nozzle Type Effects

Water Volume, Tractor Speed, and Nozzle Type Effects on Spray Coverage Eric P. Prostko, Extension Weed Specialist Paul E. Sumner, Extension Ag-Engineer The University of Georgia Peanut Achievement Club - 2007

Factors That Influence Postemergence Herbicide Performance Ø weed size Ø rate Ø environment – moisture – temperature – humidity Ø application – – – water volume (GPA) tractor speed nozzle type

Current Application Trends Ø low water volumes – 10 GPA or less Ø faster tractor speeds Ø nozzle types – Air Induction (AI) – Turbo-Jet (TJ) – Hollow-Cone (HC) Ø Why? ? – RR crops – More acres – Labor issues

U. S. Acres Planted to Herbicide Resistant Varieties Source: NASS Includes stacked

3. 5, 5. 0, 7. 0 MPH 10, 15, 20 GPA XR-Flat Fan (XR-FF) and Hollow Cone (HC) Nozzles 9 replications Kromekote water sensitive cards

Flat Fan Hollow Cone (Whirl-Jet) Examples of the nozzles used in these tests.

RESULTS

Nozzle Type and GPA Effects - I 3. 5 MPH Tractor Speed LSD 0. 10 = 3

Nozzle Type and GPA Effects - II 5. 0 MPH Tractor Speed LSD 0. 10 = 3

Nozzle Type and GPA Effects - III 7. 0 MPH Tractor Speed LSD 0. 10 = 3

10 GPA - 7 MPH – HC (12% coverage) 20 GPA – 3. 5 MPH – XR (FF) (45% coverage)

Summary Ø 3 -way interaction between tractor speed, GPA, and nozzle type Ø HC nozzles provided less coverage than XR-FF nozzles Ø Tractor speed – FF and 20 GPA = 3. 5 mph > 5. 0 mph = 7. 0 mph – HC and 15 GPA = 3. 5 mph > 7. 0 mph Ø increases in GPA improved coverage – 20 GPA > 15 GPA > 10 GPA Ø best coverage (45%) – 3. 5 MPH/20 GPA/XR-FF Ø least coverage (12%) – 7. 0 MPH/10 GPA/HC

Why is this important? Ø Application techniques for glyphosate (systemic) are not adequate for other types of herbicides such as paraquat (contact)!

Peanut Herbicides (POST) Herbicide 2, 4 -DB Basagran Cadre Classic Cobra Gramoxone Poast Pursuit Select Storm Ultra Blazer Activity systemic contact systemic contact

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