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Home , Acetochlor, Dimethenamid, Metolachlor, Propachlor

Oak Leaf Tatters – A Chemical Connection? A Pilot Study in Spring, 2006

DavidDavid LarabeeLarabee--ZierathZierath JohnJohn D.D. VargoVargo AronAron FlickingerFlickinger What is Oak Tatters?

• Abnormal curling of newly emerging leaves • Occurs only in the Spring • Has been reported in MN, WI, IL, IN, IA • Mostly seen on white and bur oaks, but can occur on red oak and hackberry 5/2/06 5/9/06

5/16/06 What happens after Tatters

• White oaks will use stored starch reserves to create a new flush of normal looking leaves. • Concern is how much reserves do our mature oaks have left?? Tatters does not affect all trees

• Trees within the same species break dormancy at different times •This explains why neighboring trees can be normal next to tattered trees. • Occurs on any aged tree; has been reported on urban and rural trees Eliminating Possible Causes

• We have used on site temperature sensors to rule out frost damage • No insects or diseases have been found on the leaves • Wind can tatter leaves, but usually affects mature leaves University of Illinois Study

• Looked at white oak in 2004 • The objective was to determine if drift could cause tatters • Treated trees at three stages with a variety of chemicals • Swollen bud, leaves unfolding, and leaves expanded • This study indicated a possible link between tatters and chloroacetamide when leaves are unfolding Population: 2.9 M

#1 in U.S. Corn Production #1 in U.S. Soybean Production #1 in U.S. Hog Production #1 in U.S. Egg Production Chloroacetanilide/Chloroacetamide Herbicides

O O

O N CH2Cl O N CH2Cl

Acetochlor

O O O O N CH2Cl N CH2Cl

S

• Chloracetanilide herbicide for control of grass and broadleaf weeds in corn • Effective weed control at use rates lower than competitor products...thus considered more “environmentally friendly” • Conditional registration granted by EPA in 1994 • Conditions attached to registration due to environmental concerns Acetochlor Conditional Registration Agreement • May not be used on certain coarse soils or when water table is 30 feet or less due to concerns of acetochlor getting into groundwater. • Extensive water monitoring studies to ensure groundwater not getting contaminated. • Use of other corn herbicides must decrease by target amounts (alachlor, metolachlor, , EPTC, butylate, 2,4-D) 2005 Iowa Pesticide Use for Corn

70% 61% 60% 50% Atrazine 40% Acetochlor 32% 32% 30% s-Metolachlor 21% 22% 20% Dimethenamid 6% % Corn Acreage Treated % Corn Acreage 10% 0% Product 2005 Iowa Pesticide Use for Corn

9,000 8276 8,000 7,000 6706 Glyphosate 6,000 Atrazine 5,000 4335 Acetochlor 4,000 s-Metolachlor 3,000 2230 Dimethenamid 2,000 1,000x 1000 Pounds a.i. 602 0 Product

Routes of Pesticide Exposure

• Spray drift during pesticide application • Volatilization of chemical after application • Entrainment of contaminated soil particles • Rain deposition Hypothesis:

Oak Tatters is associated with elevated levels of Acetochlor in Leaf Tissue, Rain and/or Air Based on – Pesticide in Rain and Air, UHL, 1996-7 – Study done at the University of Illinois – Onset of condition coinciding with introduction of Acetochlor to the market – Field observations of proximity to cropping and timing of symptoms Analytes for Study • Heavily Used – Acetochlor • Not Used Extensively – Metolachlor – Alachlor –Dimethenamid – –

Internal Standard (not sold in US) –Metazachlor Design • From April 10 through May 18 in 2006 • Two sites for a variety of proximity to or isolation from cropping • Collected Leaf, Rain, and Air Samples – Leaf – collected by Forestry staff with observations about damage and stage of growth – Air – collected on portable personal air samplers – Rain – Collected using Teflon funnels into Teflon bottles Sites

• ICS – “Iowa City Site” –Southwest of West Branch, IA – Open wooded area surrounded by Fields • WPH – “White Pine Hollow” – White Pine Hollow Forest Preserve – Heavily wooded – Relatively isolated Leaf Samples

• Collected by Forestry Personnel • Noted Damage to Correlate to Analytical Results • Extracted by routine UHL methods • Analyzed by LC/MS/MS Leaf Samples • Some leaves protected by pollination bags – Prevented access by rain and air –Prevented damage Air Samples

• For 24 hours – On 1 min., off 2 min. – 3 L/min while on – 1400 Liters of air •PUF media • Extracted at UHL • Analyzed by LC/MS/MS Rain Samples

• Collected with Teflon funnel into Teflon Bottle – Included wet and dry precipitate – Separate rain gauge to measure amount of rain • No extraction, only filtering • Analyzed by LC/MS/MS What is LC/MS/MS What is LC/MS/MS

• Separate your compounds on Liquid Chromatograph (LC) • Ionize all the compounds present • Look for the ion with the specific mass that hopefully indicates your compound • Smash that ion into smaller bits that even better indicate your compound What is LC/MS/MS

• Separate your compounds on Liquid Chromatograph (LC) • Ionize all the compounds present

Total Ion Chromatogram Compound of interest is Buried in big peak What is LC/MS/MS

• Look for the ion with the specific mass that hopefully indicates your compound

Too much competition MS Chromatogram of Ion mass = 185 What is LC/MS/MS Smash that ion into smaller bits that even better indicate your compound

MS/MS Chromatogram of Ion mass = 185 fragmented To Ion Mass 171

Sensitive and Specific Rain Results at ICS

Concentration in Rain at ICS (ng/L) 3000 Amt. per Sq. Inch Falling at ICS (pg)

250 2500

200 2000

Acetochlor

Alachlor 150 Butachlor 1500

Dimethenamid

Metolachlor 100 Propachlor1000

50 500

0 0 5/3 5/8 5/3 5/8 5/13 5/18 4/13 4/18 4/23 4/28 5/13 5/18 4/13 4/18 4/23 4/28 Rain results at WPH

Concentration in Rain at WPH (ng/L) Amt. per Sq. Inch Falling at ICS (pg)

600 12000

500 10000

400 Acetochlor Alachlor 8000

Butachlor

Dimethenamid 300 Metolachlor 6000

Propachlor

200 4000

100 2000

0 0 5/3 5/8 5/3 5/8 5/13 5/18 4/18 5/23 4/23 4/28 5/13 5/18 4/18 5/23 4/23 4/28 Air results at ICS

Concentrations in Air at ICS (ng/m3)

250

200 Acetochlor Alachlor 150 Butachlor Dimethenamid 100 Metolachlor Propachlor 50

0 ICS 4/13 ICS 4/18 ICS 4/25 ICS 5/4 ICS 5/11 ICS 5/16 Air Results at WPH

Concentrations in Air at WPH (ng/m3)

60

50 Acetochlor Alachlor 40 Butachlor 30 Dimethenamid Metolachlor 20 Propachlor 10

0 WPH 4/13 WPH 4/20 WPH 4/27 WPH 5/3 WPH 5/11 WPH 5/18 Leaf Results 3-May ICS (No observations) 9-May ICS Showing characteristic damage 16-May ICS Foliage Bur Oak 16-May ICS Foliage Bur Oak bagged 16-May ICS Foliage Bur Oak tattered

20-Apr WPH Oak leaf buds 27-Apr WPH Leaves and Flowers looked healthy 3-May WPH Damaged leaves 11-May WPH White Oak 11-May WPH Hackberry 11-May WPH Red Oak 11-May WPH White Oak unprotected leaves 11-May WPH White Oak protected leaves 18-May WPH Foliage exposed/tattered leaves 18-May WPH Foliage unexposed/pollen bag Leaf Results - Acetochlor

WPH 5/18 Unexposed WPH 5/18 Exposed/tattered WPH 5/11 White Oak protected WPH 5/11 White Oak unprotected WPH 5/11 Red Oak WPH 5/11 Hackberry WPH 5/11 White Oak

WPH 5/3 Damaged Acetochlor tattered Acetochlor healthy 6.7 3-May ICS (No observations) WPH 4/27 Healthy 9.3 9-May ICS Showing characteristic damage WPH 4/20 Oak buds 13 16-May ICS Foliage Bur Oak 0.8 16-May ICS Foliage Bur Oak bagged Acetochlor tattered 6.6 16-May ICS Foliage Bur Oak tattered Acetochlor healthy ICS 5/16 Bur Oak tattered 0.6 20-Apr WPH Oak leaf buds ICS 5/16 Bur Oak bagged 2 27-Apr WPH Leaves and Flowers looked healthy 43 3-May WPH Damaged leaves ICS 5/16 Bur Oak 50 11-May WPH White Oak 1.9 11-May WPH Hackberry ICS 5/9 damaged 37 11-May WPH Red Oak ICS 5/3 (no notes) 33 11-May WPH White Oak unprotected leaves 5.6 11-May WPH White Oak protected leaves 15 18-May WPH Foliage exposed/tattered leaves 0 102030405060 0.8 18-May WPH Foliage unexposed/pollen bag Concentration ng/g Leaf Results - Metolachlor

WPH 5/18 Unexposed WPH 5/18 Exposed/tattered WPH 5/11 White Oak protected WPH 5/11 White Oak unprotected WPH 5/11 Red Oak WPH 5/11 Hackberry WPH 5/11 White Oak WPH 5/3 Damaged WPH 4/27 Healthy Metolachlor tattered Metolachlor tattered healthy Metolachlor WPH 4/20 Oak buds Metolachlor healthy 6.3 3-May ICS (No observations) 3.5 9-May ICS Showing characteristic damage 5.4 16-May ICS Foliage Bur Oak ICS 5/16 Bur Oak tattered 4.3 16-May ICS Foliage Bur Oak bagged 3.5 16-May ICS Foliage Bur Oak tattered ICS 5/16 Bur Oak bagged ICS 5/16 Bur Oak 1 20-Apr WPH Oak leaf buds 1.3 27-Apr WPH Leaves and Flowers looked healthy ICS 5/9 damaged 6.7 3-May WPH Damaged leaves ICS 5/3 (no notes) 7.3 11-May WPH White Oak 5.2 11-May WPH Hackberry 0 5 10 15 207.3 11-May WPH Red Oak 7.8 11-May WPH White Oak unprotected leaves Concentration ng/g 2.4 11-May WPH White Oak protected leaves 18 18-May WPH Foliage exposed/tattered leaves 0.4 18-May WPH Foliage unexposed/pollen bag WPH 5/11White Oak unprotected WPH 5/11WPH White Oak protected WPH 5/18 Exposed/tattered ICS 5/16 Bur Oak bagged ICS 5/16 Bur Oak tattered efRsls–Dimethenamid Leaf Results – WPH 5/18 Unexposed WPH 5/11 White Oak WPH 5/11 Hackberry 5/11 WPH WPH 4/20 Oak buds WPH 5/11WPH Red Oak WPH 5/3 Damaged WPH 4/27 Healthy ICS 5/3 (no notes) ICS 5/9 damaged ICS 5/16 Bur Oak . . . . . 1.4 1.2 1 0.8 0.6 0.4 0.2 0 Concentration ng/g Concentration Dimethenamid healthy Dimethenamid tattered Dimethenamid . 1MyWHWhite Oakunprotectedleaves WPH 11-May Red Oak WPH 11-May Hackberry WPH 11-May White Oak 7.8 Damaged leaves WPH 11-May WPH 7.3 3-May 5.2 7.3 6.7 Foliage Bur Oak tattered ICS 16-May FoliageBur Oak characteristic Showing damage ICS 16-May (No observations) ICS 3.5 9-May ICS 3-May 5.4 3.5 6.3 81-a P Foliage exposed/tattered leaves WPH 18-May 18 Metolachlor tattered . 8MyWHFoliage unexposed/pollen bag WPH 18-May 0.4 White Oakprotectedleaves WPH 11-May 2.4 Leaves looked and Flowers healthy WPH 27-Apr 1.3 Foliage Bur Oak bagged ICS 16-May 4.3

1 20-Apr WPH Oak leaf buds leaf Oak WPH 20-Apr 1 Metolachlor healthy Future Work

• This study and others show a very strong correlation between oak leaf tatters and exposure to chloroacetanilide herbicides. • More work is needed to better understand factors that contribute to this effect and what can be done to minimize tatters. • Source of funding needed to continue this work. Most funding is directed towards impact of chemical exposure to human health. Acknowledgements

• Mark Vitosh – District Forester • Bob Hibbs - District Forester • Bruce Blair - District Forester • Linda Haugen – Forest Service • Sudesh Sikka - UHL • Sarah Espy – UHL • Karla Benninghoven – UHL •Greg Jacobs –UHL