Pendimethalin 

EPA Consultation with the National Marine 

Fisheries Service (NMFS) Regarding the 

Effects of the Pesticide Pendimethalin on 

Pacific Salmonids

1

September 27 2011

Registrant Information provided by:

BASF Corporation, Research Triangle Park, North Carolina

Craig Kleppe – Product Registration Manager

Scott Jackson – Stewardship Manager

Spencer Mortensen – Principal Ecotoxicologist

Joe Wisk – Manager, Ecotoxicology
Pendimethalin

Herbicide Use Profile

 Mode of Action - meristematic inhibitor that interferes with the plant’s cellular 

division or mitosis (prohibits microtubule assembly) 

 Terrestrial uses, no aquatic uses

 Soil active herbicide must be applied prior to weed seed germination, either before 

crop seeding or shortly after

EPA Consultation with NMFS - Pendimethalin, September 27 2011 2

crop seeding or shortly after

 Application methods – aerial spray, ground spray or by spreading dry granule, 

chemigation, flood irrigation 

 Use patterns – applied to soil surface broadcast, banded, directed between rows

 Crop Uses – applied to field and rows crops, fruit & nut tree orchards, vineyards, 

vegetables, fallow

 Non-Crop Uses – applied to turfgrass, sod farms, golf courses, grounds & 

landscape maintenance, noncropland areas, ornamental production, plantations
Pendimethalin

Current Registered Crop Uses (1)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

carrots 1 1 60 PRE or Layby

carrot grown for seed 2 2 60 Layby

Vegetable, tuberous and 

corm 1C

potato (white) 1.5 1.5 none PRE or PRE incorporated or EPOST

garlic

1.5 1.5 45 to 60 PRE or POST

dry bulb onions 1.5 1.5 45 (or 60 

in CA)

Mineral soils: 

POST (all states)

Vegetable, Root 1A

EPA Consultation with NMFS - Pendimethalin, September 27 2011 3

in CA) POST (all states)

dry bulb onions

1.5 1.5 45

Mineral soils:

LOOP and POST (only in CO, KS, NE 

states)

dry bulb onions 1.5 1.5 45 Mineral soils: 

PPI (only in CO, TX states)

dry bulb onions

2 2 45

Mineral soils: 

PPS between beds before 

transplanting or POST (only in ID, OR, 

WA states)

dry bulb onions 2 5.94 45 Muck soils: 

PRE or LOOP or POST 

dry bulb onions

1.425 1.425 45

Yes, Idaho, 

Oregon, 

Washington

Delayed PRE

dry bulb onions 0.7 1.5 60 Yes, California LOOP

dry bulb shallots 1.5 1.5 45 (or 60 

in CA)

Mineral soils: 

POST (all states)

dry bulb shallots 2 5.94 45 Muck soils: 

PRE or LOOP or POST 

green onions 1 2 30 PRE or POST

leek 1 2 30 PRE or POST

spring onions or scallions 1 2 30 PRE or POST

Japanese bunching onion 1 2 30 PRE or POST

green shallots 1 2 30 PRE or POST

green eschalots 1 2 30 PRE or POST

Bulb Vegetables 3
Pendimethalin

Current Registered Crop Uses (2)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

broccoli 1 1 60 Pre-transplanting or POST or PDIR 

between rows

broccoli, Chinese 1 1 60 Pre-transplanting or POST or PDIR 

between rows

brussels sprouts 1 1 60 Pre-transplanting or POST or PDIR 

between rows

cabbage Pre-transplanting or POST or PDIR 

EPA Consultation with NMFS - Pendimethalin, September 27 2011 4

cabbage 1 1 70 Pre-transplanting or POST or PDIR 

between rows

cabbage, Chinese (napa) 1 1 70 Pre-transplanting or POST or PDIR 

between rows

cabbage, Chinese mustard 1 1 70 Pre-transplanting or POST or PDIR 

between rows

cauliflower 1 1 70 Pre-transplanting or POST or PDIR 

between rows

cavalo broccolo 1 1 70 Pre-transplanting or POST or PDIR 

between rows

kohlrabi 1 1 70 Pre-transplanting or POST or PDIR 

between rows

snap bean 1.5 1.5 none PPS or PPI

dwarf pea 1.5 1.5 none PPS or PPI

edible pod pea 1.5 1.5 none PPS or PPI

lima bean 1.5 1.5 none PPS or PPI

southern pea (cowpea) 1.5 1.5 none PPS or PPI

English pea 1.5 1.5 none PPS or PPI

garden pea 1.5 1.5 none PPS or PPI

green pea 1.5 1.5 none PPS or PPI

Brassica Head & Stem 

Vegetables 5A

Legume vegetables (Edible 

podded beans & peas) 6A

Legume vegetables 

(Succulent shelled) 6B
Pendimethalin

Current Registered Crop Uses (3)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

dry beans (red kidney)

1.5 1.5 none

PPS or PPI or 

PRE (only in CO, ID, KS, MT, NE, NM, OR, 

WA, WY states)

dry beans (black)

1.5 1.5 none

PPS or PPI or 

PRE (only in CO, ID, KS, MT, NE, NM, OR, 

WA, WY states)

dry beans (turtle)

1.5 1.5 none

PPS or PPI or 

PRE (only in CO, ID, KS, MT, NE, NM, OR, 

Legume vegetables

(dry shelled) 6C

EPA Consultation with NMFS - Pendimethalin, September 27 2011 5

1.5 1.5 none PRE (only in CO, ID, KS, MT, NE, NM, OR, 

WA, WY states)

dry beans (cranberry)

1.5 1.5 none

PPS or PPI or 

PRE (only in CO, ID, KS, MT, NE, NM, OR, 

WA, WY states)

dry beans (small white type)

1.5 1.5 none

PPS or PPI or 

PRE (only in CO, ID, KS, MT, NE, NM, OR, 

WA, WY states)

chickpeas (garbanzo beans) 1.5 1.5 nonePPS or PPI or 

PRE (only in ID, OR, WA states)

sweet lupins 1.5 1.5 none PPS or PPI or PRE

lentils 1.5 1.5 nonePPS or PPI or 

PRE (only in ID, OR, WA states)

dry pea 1.5 1.5 nonePPS or PPI or 

PRE (only in ID, OR, WA states)

pigeon pea 1.5 1.5 none PPS or PPI

eggplant 1.5 1.5 21 PPI or Pre-transplanting or PDIR

groundcherry 1.5 1.5 70 PPI or Pre-transplanting or PDIR

peppers, bell 1.5 1.5 70 PPI or Pre-transplanting or PDIR

peppers, non-bell 1.5 1.5 70 PPI or Pre-transplanting or PDIR

pepino 1.5 1.5 70 PPI or Pre-transplanting or PDIR

tomatilla 1.5 1.5 70 PPI or Pre-transplanting or PDIR

tomato 1.5 1.5 70 PPI or Pre-transplanting or PDIR

Fruiting Vegetables 8

(continued)

Legume vegetables 

(dry shelled) 6C
Pendimethalin

Current Registered Crop Uses (4)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

calamondin 6 6 1 Directed under tree canopy

citrus citron 6 6 1 Directed under tree canopy

citrus hybirds 6 6 1 Directed under tree canopy

grapefruit 6 6 1 Directed under tree canopy

kumquat 6 6 1 Directed under tree canopy

EPA Consultation with NMFS - Pendimethalin, September 27 2011 6

kumquat 6 6 1 Directed under tree canopy

lemon 6 6 1 Directed under tree canopy

lime 6 6 1 Directed under tree canopy

mandarin (tangerine) 6 6 1 Directed under tree canopy

orange (sweet) 6 6 1 Directed under tree canopy

orange (sour) 6 6 1 Directed under tree canopy

pummelo 6 6 1 Directed under tree canopy

satuma mandarin 6 6 1 Directed under tree canopy

tangelo 6 6 1 Directed under tree canopy

non-bearing citrus trees 6 6 na PPS or PPI or PRE

apple 4 4 60 Directed under tree canopy

crabapple 4 4 60 Directed under tree canopy

loquat 4 4 60 Directed under tree canopy

mayhaw 4 4 60 Directed under tree canopy

pear 4 4 60 Directed under tree canopy

pear, oriental 4 4 60 Directed under tree canopy

quince 4 4 60 Directed under tree canopy

non-bearing pome fruit trees 4 4 na PPS or PPI or PRE

Pome Fruits 11

Citrus Fruits 10
Pendimethalin

Current Registered Crop Uses (5)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

apricot 4 4 60 Directed under tree canopy

aprium 4 4 60 Directed under tree canopy

cherry, sweet 4 4 60 Directed under tree canopy

cherry, tart 4 4 60 Directed under tree canopy

nectarine 4 4 60 Directed under tree canopy

peach 4 4 60 Directed under tree canopy

plum 4 4 60 Directed under tree canopy

plum, chicksaw 4 4 60 Directed under tree canopy Stone fruits 12

EPA Consultation with NMFS - Pendimethalin, September 27 2011 7

plum, chicksaw 4 4 60 Directed under tree canopy

plum, Damson 4 4 60 Directed under tree canopy

plum, Japanese 4 4 60 Directed under tree canopy

plumcot 4 4 60 Directed under tree canopy

pluot 4 4 60 Directed under tree canopy

prune 4 4 60 Directed under tree canopy

non-bearing stone fruit trees 4 4 na PPS or PPI or PRE

juneberry 4 4 60 Directed under tree canopy

pomegranate 4 4 60 Directed under tree canopy

almond 6 6 60 Directed under tree canopy

beech nut 6 6 60 Directed under tree canopy

Brazil nut 6 6 60 Directed under tree canopy

butternut 6 6 60 Directed under tree canopy

cashew 6 6 60 Directed under tree canopy

chestnut 6 6 60 Directed under tree canopy

chinquapin 6 6 60 Directed under tree canopy

filbert (hazelnut) 6 6 60 Directed under tree canopy

hickory nut 6 6 60 Directed under tree canopy

macadamia nut 6 6 60 Directed under tree canopy

pecan 6 6 60 Directed under tree canopy

pistachio 6 6 60 Directed under tree canopy

walnut 6 6 60 Directed under tree canopy

non-bearing nut trees 6 6 na PPS or PPI or PRE

Tree Nuts 14

Stone fruits 12
Pendimethalin

Current Registered Crop Uses (6)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

corn, field 2 2 21 PRE or POST or CULTI-Spray

corn, pop 2 2 21 PRE or POST

corn, field seed 2 2 21 PRE or POST

corn, pop seed 2 2 21 PRE or POST

corn, fresh sweet 2 2 21 PRE or POST

sorghum, grain 1.5 1.5 21 Cereal Grains 15 CULTI-Spray or 

EPA Consultation with NMFS - Pendimethalin, September 27 2011 8

1.5 1.5 21 EPOST (in certain states)

rice (dry seeded) 1 1 none PRE or Delayed PRE or EPOST

rice (water seeded) 1 1 none POST

wheat 1.5 1.5 11 to 60 PRE or Delayed PRE or POST

triticale 1.5 1.5 11 to 60 PRE or Delayed PRE or POST

Bermudagrass (grown for hay) 4 4 60 Winter Dormancy

Bermudagrass (pasture for grazing) 4 4 45 Winter Dormancy

perennial grass grown for seed 4 4 90 POST

perennial grass grown for straw 4 4 90 POST

Grass Forage, Fodder and 

Hay 17
Pendimethalin

Current Registered Crop Uses (7)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum

Single

Application 

Use Rate

(lb ai/A)

Maximum

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

alfalfa stand establishment 0.7 4 na PPI or PRE

alfalfa (seedling) 1 4 na POST

alfalfa (grown for forage) 4 4 28 dormancy or after cutting or POST

alfalfa (grown for hay) 4 4 28 dormancy or after cutting or POST

alfalfa (grown for seed) 4 4 90 dormancy or POST

artichoke, globe 3.9 3.9 200 Pre-transplanting

artichoke, globe 1.425 1.425 60 Pre-transplanting

asparagus 3.9 3.9 14 PRE to spear emergence

clover grown for seed 3.8 3.8 na

Yes, Idaho and 

Oregon

POST

EPA Consultation with NMFS - Pendimethalin, September 27 2011 9

3.8 3.8 na OregonPOST

cotton 2 2 60 PPS or PPI or PRE or Layby

cotton 0.95 2 60 POST

fallow 1.5 na na PPS 

grape, bearing 6 6 90 Directed under vine canopy

grape, non-bearing 6 6 na PPS or PPI or PRE

guayule, non-bearing 4 6 na Yes, Arizona Directed under plant canopy

olive, bearing 4 4 60 Directed under tree canopy

olive, non-bearing 4 4 na Directed under tree canopy

peanut 1 1 none PPI or PRE

peanut 1.5 1.5 nonePPI or 

PRE (only in AL, FL, GA states)

peppermint 2 2 90 PRE

spearmint 2 2 90 PRE

soybean 2 2 85 PPS or PPI or PRE

strawberry 1.5 3 35 PPS or Pre-transplanting and POST

between rows

strawberry non-bearing 1.66 1.66 365 Pre-transplanting 

(only in OR and WA states)

sugarcane 4 5.94 90 PRE or Layby

sugarcane (fallow ground in Louisiana) 2.5 5.94 90 PPS and PRE or Layby

sugarcane (drainage areas in Louisiana) 3.325 5.94 na PPS

sunflowers 1.73 1.73 none fall PPI (only in MN, ND, SD states)

sunflowers 1.5 1.5 none PPI or PRE

tobacco 1.5 1.5 none PPI or Layby

Individual Crops na

(continued)

Individual Crops

na
Pendimethalin

Current Registered Non-Crop Uses (1)

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

turfgrass on golf courses 3 4.5 na anytime prior to weed germination

turfgrass on sod farms 2 3.4 na anytime prior to weed germination

turfgrass on residential lawns 2 3.5 na anytime prior to weed germination

turfgrass maintained non-residential areas 3 4.5 na anytime prior to weed germination

turfgrass in landscaped ornamental areas 3 4.5 na anytime prior to weed germination

industrial (unimproved) turf 4 8 na anytime prior to weed germination

EPA Consultation with NMFS - Pendimethalin, September 27 2011 10

general grounds maintenance 4 8 na anytime prior to weed germination

general landscape maintenance 4 8 na anytime prior to weed germination

noncropland areas 4 8 na anytime prior to weed germination

wildflower plantings 4 8 na anytime prior to weed germination

bulb plantings 4 8 na anytime prior to weed germination

tree seedling nurseries 4 8 na anytime prior to weed germination

tree plantations 4 8 na anytime prior to weed germination

ornamental production 4 8 na anytime prior to weed germination

Non-Crop Uses na
Pendimethalin

New Crop Uses currently under EPA review

Crop Grouping

(if applicable)

Crop 

Group 

Number

Crop

Maximum 

Single 

Application 

Use Rate

(lb ai/A)

Maximum 

Seasonal 

Application 

Use Rate

(lb ai/A)

PreHarvest 

Interval 

(days)

State-specific 

Special Local 

Needs 

24(c) label ?? 

Application Use Pattern*

mustard greens 1 1 21 POST

broccoli raab 1 1 21 POST

Chinese cabbage (bok choy) 1 1 21 POST

collards 1 1 21 POST

kale 1 1 21 POST

New Crop Uses Pending at EPA as of July 2011

Brassica Leafy Greens 5B

EPA Consultation with NMFS - Pendimethalin, September 27 2011 11

kale

mizuna 1 1 21 POST

mustard spinach 1 1 21 POST

rape greens 1 1 21 POST

turnip greens 1 1 21 POST

canteloupe 1 2 35 Directed to row middles

citron melon 1 2 35 Directed to row middles

muskmelon 1 2 35 Directed to row middles

watermelon 1 2 35 Directed to row middles

Amur river grape 6 6 60 Directed under vine canopy

gooseberry 6 6 60 Directed under vine canopy

fuzzy kiwifruit 6 6 60 Directed under vine canopy

hardy kiwifruit 6 6 60 Directed under vine canopy

maypop 6 6 60 Directed under vine canopy

Schisandra berry 6 6 60 Directed under vine canopy

leaf lettuce 1 1 20 POST

Vegetable soybean (edamame) 1.5 1.5 85 PPS or PPI or PRE Individual Crops na

Melons 9A

Small Fruit Vine Climbing 

(except grape) 13-07E
Pendimethalin

Herbicide Use Rates

 Maximum single application crop use rate

- in field and rows crops:

4 lbs ai/A in asparagus, artichoke, alfalfa, bermudagrass, sugarcane

- in tree orchards or vines crops:

EPA Consultation with NMFS - Pendimethalin, September 27 2011 12

6 lbs ai/A in citrus, grape, tree nuts

 Maximum single application non-crop use rate

- in turfgrass:

3 lbs ai/A in golf, residential lawns

- in grounds/landscape maintenance and ornamentals production:

4 lbs ai/A
Pendimethalin

Formulated Products 

 Liquid Formulations

- EC (emulsifiable concentrate)

- CS (capsulated aqueous suspension) 

EPA Consultation with NMFS - Pendimethalin, September 27 2011 13

 Granular Formulations

- G (spreadable granule)
Pendimethalin Studies of Interest 

for Ecological Risk Assessment 

14
Regulatory Studies Already Submitted to EPA

1) Fate, Transport, and Transformation Data

 Lab Degradation Studies

 Hydrolysis

 Aqueous photolysis

 Soil photolysis

 Lab Metabolism Studies

EPA Consultation with NMFS - Pendimethalin, September 27 2011 15

 Lab Metabolism Studies

 Aerobic soil and aquatic

 Anaerobic soil and aquatic

 Mobility Studies

 Leaching and adsorption/desorption

 Volatility (lab)

 Field Dissipation Studies

 Several soil and two sediment
Regulatory Studies Already Submitted to EPA

2) Ecological Effects Data (Aquatic)

 Invertebrates

 Acute freshwater (Daphnia)

 Acute marine (oyster shell deposition & Mysid shrimp)

 Life cycle and reproduction (Daphnia)

 Chironomus spiked sediment toxicity

 Fish

EPA Consultation with NMFS - Pendimethalin, September 27 2011 16

 Fish

 Acute freshwater (bluegill, trout, catfish)

 Acute marine (sheepshead minnow)

 Fish full life cycle (fathead minnow)

 Accumulation and BCF studies

 Non-Target Plants

 Lemna

 Algae (freshwater green and blue-green algae, freshwater and marine diatom, marine 

diatom)
Regulatory Studies Already Submitted to EPA

3) Ecological Effects Data (Terrestrial)

 Avian

 Acute oral toxicity (quail)

 Dietary LC50 (quail and duck)

 Reproduction (quail and duck)

EPA Consultation with NMFS - Pendimethalin, September 27 2011 17

 Reproduction (quail and duck)

 Invertebrates

 Honeybee acute contact

 Non-Target Plants

 Seedling emergence (Tier I & II)

 Vegetative vigor (Tier I & II)
Higher-Tiered Ecological Studies in the Aquatic 

Environment to Address EU Regulatory Concerns

 Studies not previously submitted to EPA

- outdoor pond mesocosms, effects on fish and pendimethalin fate 

- outdoor pond mesocosms, effects on other aquatic organisms

- bioaccumulation in Tubifex

EPA Consultation with NMFS - Pendimethalin, September 27 2011 18

- bioaccumulation in Tubifex

- full life cycle test in Zebra fish
Pendimethalin Mitigation Measures

19
Pendimethalin

Mitigation Measures for Endangered Species

 Spray Buffer Zones on Product Labels since 2006

Endangered Species Protection

This product may have effects on federally listed threatened or endangered plant species or their critical 

habitat. When using this product, you must follow the measures contained in the Endangered Species 

Protection Bulletin for the county or parish in which you are applying the pesticide. To determine whether 

EPA Consultation with NMFS - Pendimethalin, September 27 2011 20

Protection Bulletin for the county or parish in which you are applying the pesticide. To determine whether 

your county or parish has a Bulletin, and to obtain that Bulletin, consult http://www.epa.gov/espp/, or call 

1-800-447-3813 no more than 6 months before using this product. Applicators must use Bulletins that are 

in effect in the month in which the pesticide will be applied. New Bulletins will generally be available from 

the above sources 6 months prior to their effective dates.

If endangered plant species occur in proximity to the application site, the following mitigation measures are 

required:

• If applied by ground, leave an untreated buffer zone of 200 feet. The product must be applied using a low 

boom (20 inches above the ground) and ASAE fine to medium/coarse nozzles.

• If applied by air, leave an untreated buffer zone of 170 feet. Must use straight-stream nozzles (D-6 or 

larger); wind can be no more than 8 mph, and release height must be 15 feet or less.
Pendimethalin

BiOps 

 Pendimethalin labels already include:

 Environmental Hazard statements... 

1 - This product is toxic to fish. 

2 - DO NOT apply directly to water, or to areas where surface water is present, or

EPA Consultation with NMFS - Pendimethalin, September 27 2011 21

to intertidal areas below the mean high water mark. 

3 - Drift and runoff from treated areas may be hazardous to aquatic organisms in

adjacent aquatic sites. 

4 - DO NOT contaminate water when disposing of equipment washwaters or rinsate.

 Risk-based spray buffers to protect Endangered Species

 BASF proposes a determination by NMFS of “No Jeopardy”