Comparing Volatility of Three Forms of 2,4-D when Applied in the - PowerPoint PPT Presentation

Comparing Volatility of Three Forms of 2,4-D when Applied in the Field Culpepper, Richburg, Sosnoskie, Braxton

Future Technology Technology of Today Herbicide Cost of $39/A Herbicide Cost of $59/A

Sensitivity of Non 2,4-D Resistant Cotton to 2,4-D 2,4-D resistant

Sensitivity of Vegetables to 2,4-D

2011 GA Vegetable Facts • Approximately 200,000 acres • 40 different vegetables grown • 3rd largest vegetable producing state for A • Farm Gate Value: $1,200,000,000

Many of these crops are grown in the same areas often by the same growers.

Off Target Movement Concern • Physical drift • Volatility

Off Target Movement Concern • Physical drift = related to someone most likely not following label recommendations • Volatility = one can do everything perfect and there can still be a serious issue

Objective Volatility needs to be eliminated or at least know exactly how far it could move 2,4-D Choline 2,4-D Amine 2,4-D Ester

Sunbelt Ag Expo 2010 N 2,4-D Choline 2,4-D Amine 2,4-D Ester

Sunbelt Ag Expo 2011 N 2,4-D Choline 2,4-D Ester 2,4-D Amine

Potted cotton plants placed in all directions @ 5, 10, 20, 40, 80 and 160 ft N NW NE W E SW SE S Treated area = 90 foot by 90 foot

Potted plants each year = 1728 Four plants per location for 48 hrs, 1 st 24 h, 2 nd 24 h. N NW NE W E SW SE S

Sunbelt Ag Expo 2011 N

Methods Mix location: off site Rate: 2 lb ae/A glyphosate + 2 lb ae/A 2,4-D Application: FF 11002 DG, 25 PSI, 15 GPA Time of day: before 10 am Soil: 88% sand, 12% silt; pre-irrigated

Controls for Methods Truck ride (2010, 2011): no damage Herbicide application (2011): no damage Plant contact (2011): no damage

2010 Temperature (F) 9/ 9/ 2010 9/ 10/ 2010 9/ 11/ 2010 95 85 75 Application Sept 9. 65 800 930 1100 1230 1400 1530 1700 1830 2000 2130 2300 30 200 330 500 630 8 am 7 am Max soil temp range 99-103 F; mix of clouds and sun; max sustained wind 8 mph.

2011 Temperature (F) Aug. 30 Aug. 31 Sept. 1 95 85 75 65 8 am 7 am Application Aug 30. Max soil temp ranged 106-113 F; completely sunny; max sustained wind 11 mph.

Visual Cotton Injury Heights Nodes

Cotton Injury (%) as Influenced by Distance. In-field 48 hours. 2010. = Amine = Choline = Ester 80 Form x distance ( P ≤ 0.05) Ester > Amine, Choline, for all distances 60 Ester: 5 > 10 > 20 > 40 > 80 > 160 Amine: 5 > 10 > 20–160 53 40 45 Amine 5–10 > Choline 5-10 38 20 20 5 0 0 20 80 5 10 40 160 Distance Data pooled over direction.

Cotton Injury (%) as Influenced by Distance. In-field 48 hours. 2011. = Amine = Choline = Ester 80 Form x distance ( P ≤ 0.05) 73 Ester > Amine, Choline, for all distances 69 60 Ester: 5 > 10 > 20 > 40 > 80 > 160 58 Amine: 5 > 10 > 20–160 40 Amine 5–10 > Choline 5-10 38 20 20 4 0 20 80 5 10 40 160 Distance Data pooled over direction.

Ester Choline

Cotton Injury (%) from Ester as Influenced by Distance & Time. 2010. = 0-24 h = 24-48 h = 0-48 h 80 Time x distance ( P ≤ 0.05) 0-48 h ≥ 0-24 h ≥ 24-48 h, for all distances 60 40 20 0 20 80 5 10 40 Distance (ft) Data pooled over direction.

Cotton Injury (%) as Influenced by Duration In-Field. 2011. = 0-24 h = 24-48 h = 0-48 h 80 Time x distance ( P ≤ 0.05) 0-48 h ≥ 0-24 h ≥ 24-48 h, for all distances 60 40 20 0 20 80 5 10 40 Distance (ft) Data pooled over direction.

Cotton Injury (%) by Ester as Influenced by Direction. In-field 48 hours. = 2011 = 2010 80 60 40 20 0 E S SW W N NE SE NW Direction Data pooled over distance

2011 Wind Direction. Day of Application Application to 2 pm N (0 to 5.5 mph) NW NE 2 to 5 pm W E (4-11 mph) SW SE 5 to 9 pm S (11 to 0 mph)

Volatility Injury to Cotton: Tunnel Data 20 plants assigned a location number

Cotton Injury (%) as Influenced by Tunnel. 2010. = 0-24 h = 24-48 h = 0-48 h 80 0-48 h: Ester > Amine > Choline 0-24 h: Ester > Amine > Choline 60 24-48 h: Ester > Amine = Choline 40 20 0 Ester Choline Amine Data pooled over 20 plants for each herbicide and time interval.

Cotton Injury (%) as Influenced by Tunnel. 2011. = 0-24 h = 24-48 h = 0-48 h 80 0-48 h: Ester > Amine > Choline 0-24 h: Ester > Amine = Choline 60 24-48 h: Ester > Amine = Choline 40 20 0 Ester Choline Amine Data pooled over 20 plants for each herbicide and time interval.

Conclusions 1. Ester formulation should not be applied in Georgia during similar conditions. 2. Choline formulation offers the lowest potential for off-target movement from volatility.

Comments?