Weed Management in Pumpkins Weed Identificationvegetables.tennessee.edu/pdfs/Pumpkin Weed...

10/5/2010

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Weed Management in Pumpkins

Jose J Vargas and Greg Armel Weed Science in Vegetable Crops, Ornamentals, and Invasive Weeds

Weed Identification

How to Identify Grass Weeds• Growth pattern

– Prostate– Erect

• Roots– Fibrous– Rhizomatic

• Ligules– No ligule– Fringe of hairs– Membranous

• Auricle– Present or not

* Pictures courtesy of the Virginia Tech Weed ID guide

• Leaf surface– pubescent (hairy)– concentrated hairs– glabrous (smooth or not hairy)

• Inflorescence (seed head)Inflorescence (seed head)– digitate– spike– panicle- open to dense

• Leaf/bud position– folded– rolled

* Most pictures courtesy of the Virginia Tech Weed ID guide; Large crabgrass seedhead found at………. http://www.turf.uiuc.edu/weed_web/crabgrass/crabgrass_sh.htm

How to Identify Broadleaf Weeds

• Growth characteristics– Herbaceous– Woody– Vines

• Leave characteristics– Cotyledon

• Shape• Size

• True Leaf• Compound or simple• Shape• Size• Venation• Leaf surface- glabrous vs. pubescent

* Pictures courtesy of the Virginia Tech Weed ID guide

• Leaf position• Alternate vs. opposite

• Root characteristicsFibrous vs taproots– Fibrous vs. taproots

– Rhizomes vs. adventitious

• Nodes and Internodes– Length– Bud shape and size

• Flowers, fruits, and seeds

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Preemergence Herbicide Optionsg p

Curbit® 3 lb EC• Common name: Ethalfluralin• Mode of action: Mitotic inhibitor• Manufacturer: Loveland Products• Weeds controlled: Grasses and some small

d d b dl f dseeded broadleaf weeds• Applications:

– PRE- 3 to 4 ½ pints/acre• No later than 2 days after seeding• Do not soil incorporate• May apply POST over top of transplants• Course soils- 3 pints/acre• Medium soils- 3 to 4 pints/acre• Fine soils- 4 to 4 ½ pints/acre

F FF

NO2 NO2

N

Curbit® 3 lb EC- Grass Weeds Controlled

• Broadleaf signalgrass• Crabgrass

– LargeS th– Smooth

• Goosegrass• Foxtail millet• Johnsongrass (seedling)• Fall panicum• Texas panicum

• Carpetweed

Curbit® 3 lb EC- Broadleaf Weeds Controlled

Carpetweed• Lambsquarters• Pigweed

– Prostrate, redroot, smooth, spiny• Purslane

Other Crops Where You can Use Curbit® 3 lb EC

• CucumbersM l• Melons

• Summer squash• Winter squash• Watermelons• Consult label for specific rates, timings,

and restrictions.

Dual Magnum® 7.62 lb EC• Common name: s-metolachlor• Mode of action: LCFA biosynthesis inhibitor• Manufacturer: Syngentay g• Weeds controlled: Grasses, yellow nutsedge,

and some small seeded broadleaf weeds• Applications:

– PRE- 1 to 1.33 pints/acre• Inter-row or inter-hill application• DO NOT APPLY to 1 foot band around the row

N

O

Cl

O

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Grasses and Sedges Controlled by Dual Magnum® 7.62 lb EC

• Controls all the grasses controlled by Curbit® 3 EC, except Texas panicum, plus the following:– Barnyardgrass– Foxtails

• green, giant, yellow, and bristly– Crowsfootgrass– Witchgrass– Yellow nutsedge

Broadleaf Weeds Controlled by Dual Magnum® 7.62 lb EC

• Controls all the broadleaf weeds controlled by Curbit® 3 EC, except lambsquarters plus the following:lambsquarters, plus the following:– Additional Amaranthus spp.

• Waterhemp (common, tall)• Powell amaranth• Palmer Amaranth

– Tropical spiderwort

Picture of tropical spiderwort found at: http://www.cropsci.ncsu.edu/yorkproject/newpage_files/GOOD%20closeup.jpg

Other Crops Where You can Use Dual Magnum® 7.62 lb EC

• Corn• Cotton• Grasses grown for seed• Rhubarb• Sunflower• Sorghum (grain or forage)• Soybean• Tomato• Consult label for specific rates, timings, and

restrictions.

Strategy® 2.1 lb EC• Common name: Ethalfluralin (Curbit) 1.6 lbs ai/gal +

Clomazone (Command) 0.5 lbs ai/gal• Mode of action: Mitotic inhibitor + Carotenoid inhibitor• Manufacturer: Loveland Products• Weeds controlled: Grasses and some small seeded

b dl f dbroadleaf weeds• Applications:

– PRE- 2 to 6 pints/acre• No later than 2 days after seeding• Do not soil incorporate• Do not apply postemergence over transplants• Do not use over or under plastic mulch• Course soils- 2 to 3 pints/acre• Medium soils- 3 to 4 pints/acre• Fine soils- 4 to 6 pints/acre

F FF

NO2 NO2

N

ON

O

Cl

Weeds controlled by Strategy© over Curbit©

• Controls all the weeds controlled by Curbit®3 EC plus the following:– Prickly sida– Spurred anoda– Velvetleaf– Venice Mallow– Cocklebur*– Common ragweed*– Smartweed*

* Suppression only

Other Crops Where You can Use Strategy® 2.1 lb EC

• Cucumbers• Squash• Melons• Watermelons• Consult label for specific rates, timings,

and restrictions.

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Postemergence Herbicide OptionsPostemergence Herbicide Options

Sandea® 75%DF• Common name: Halosulfuron• Mode of action: ALS-inhibitor• Manufacturer: Gowan• Weeds controlled: Broadleaf and sedge

A li ti• Applications:– PRE- ½ to ¾ oz/acre

• Minimum 7 day pre-transplant– POST over-the-top- ½ to ¾ oz/acre

• 2 to 5 leaf stage (4 to 5 leaf stage direct seeded) before first flower

– POST directed or row middle- ½ to 1 oz/acre– Maximum of 2 applications totaling 2 oz/acre– Must include 0.25% NIS

SO

ONN

O

N

N

O

ON

N

ClO

O

Sandea® 75%DF- Weeds Controlled– Cocklebur (PRE, POST)– Common Ragweed (PRE, POST)– Giant Ragweed (POST)– Eclipta (PRE, POST*)– Groundsel (PRE)– Hemp sesbania (POST)– Hairy galinsoga (PRE POST)Hairy galinsoga (PRE, POST)– Pokeweed (POST)– Pigweed (PRE, POST)– Prickly sida (POST)– Purslane (PRE*, POST*)– Smartweed/ladysthumb (PRE, POST)– Velvetleaf (PRE, POST)– Wild mustard (PRE, POST)– Wild radish (PRE, POST)– Yellow Nutsedge (PRE*, POST^)– Purple Nutsedge (PRE*, POST^) *suppression

^ Best control may require highest rates/multiple applications

Comparing the Postemergence Applied Grass Killers

Common nameCommon name ClethodimClethodim SethoxydimSethoxydim

Trade nameTrade name Select MaxSelect Max®® PoastPoast®®

ManufacturerManufacturer ValentValent BASFBASF

Use rateUse rate 99--16 fl oz/acre annual 16 fl oz/acre annual grassesgrasses

No more than 64 fl oz/ acre No more than 64 fl oz/ acre per seasonper season

1.5 pints/acre1.5 pints/acreNo more than 3 pints/acre No more than 3 pints/acre

per seasonper seasonper seasonper season

14 days appl. window14 days appl. window

Days needed after Days needed after transplant before transplant before applicationapplication

00 00

Preharvest interval Preharvest interval (days)(days)

14 14 1414

AdjuvantsAdjuvants 0.25% NIS0.25% NIS 1% COC1% COC

Grasses controlledGrasses controlled All annuals except All annuals except goosegrass; excellent on goosegrass; excellent on

perennial grassesperennial grasses

Excellent on annual grasses Excellent on annual grasses and most perennialsand most perennials

Gramoxone Inteon® 75%DF• Common name: Paraquat• Mode of action: PSI inhibitor• Manufacturer: Syngenta• Weeds controlled: Broadleaf and small grasses

N+ N+ CH3CH3

g• Applications:

– POST directed or hooded application 1.9 to 2.4 pt/acre

• For weed control or harvest aid• Do not contact foliage of desirable crop

– Maximum of 3 applications– Must include 0.25% NIS

Estimated Cost of HerbicidesHerbicideHerbicide Use Rate Use Rate Estimated CostEstimated CostCurbitCurbit®® 3 to 4 ½ pt/acre3 to 4 ½ pt/acre $23 $23 -- $35$35Dual MagnumDual Magnum®® 1 to 1.33 pt/acre1 to 1.33 pt/acre $15 $15 -- $20$20StrategyStrategy®® 2 to 6 pt/acre2 to 6 pt/acre $25 $25 -- $75$75SS ®® 0 0 /0 0 / $20$20 $ 0$ 0SandeaSandea®® 0.5 to 0.75 oz/acre0.5 to 0.75 oz/acre $20 $20 -- $40$40

Gramoxone Gramoxone InteonInteon®®

1.9 to 2.4 pt/acre1.9 to 2.4 pt/acre $8 $8 -- $10$10

PoastPoast®® 1.5 pt/acre1.5 pt/acre $15$15Select MaxSelect Max®® 9 to 16 fl/oz9 to 16 fl/oz $10 $10 -- $17$17

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Building a Weed Management Program in Pumpkin

• Preemergence herbicides are important– Yield impacts are greatest within 3 to 5 weeksYield impacts are greatest within 3 to 5 weeks

after crop emergence• Postemergence tank mix compatability

– Do not mix Sandea with POST grass killer– Space broadleaf and grass herbicide

applications 3 to 5 days apart• Know your weeds to reduce costs!!!!!!

Building a Weed Management- Weed Scenarios

• Johnsongrass (or other perennial grasses)– PRE herbicide fb Select Max or Poast

• Morningglory or Field Bindweed– PRE herbicide fb hooded application to the row middles with paraquat

• Yellow Nutsedgeg– PRE Dual Magnum and/or POST Sandea

• Malvaceae weeds– Velvetleaf, spurred anoda, prickly sida, mallow spp.– PRE Strategy and/or POST Sandea (velvetleaf, prickly sida)

• Eastern black nightshade– PRE Dual Magnum

• Pigweed spp.– PRE herbicide and/or POST Sandea (weak on spiny and prostate

pigweed)• Common lambsquarters

– PRE Curbit or Strategy

EVALUATIONS OF AMINOCYCLOPYRACHLOR FORMULATIONS FOR

BROADLEAF WEED CONTROL IN PUMPKIN.

J. Vargas and G.R. ArmelUniversity of Tennessee, Knoxville, TN

Introduction

Objectives

M t i l & M th dMaterials & Methods

Results & Discussion

Conclusion

Introduction

Aminocyclopyrachlor at a glance

N

NCl

N

O

O

N

NCl

N

O

O

• Aminocyclopyrachlor is an auxin mimic herbicide containing chlorine,amino, and carboxylic acid groups which are prevalent components ofchemistry that mimic indole-3-acetic acid.

• The first pyrimidine carboxylic acid herbicides and are currently underdevelopment / registration by DuPont Crop Protection.

• The structure of aminocyclopyrachlor is very similar to pyridinecarboxylic acid herbicides like picloram, clopyralid and aminopyralid withtwo exceptions…….

DPX‐MAT28 DPX‐KJM44

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• Provides broad-spectrum control of several broadleafweeds and certain grasses including glyphosate, ALS- andtriazine resistant weeds.

• Proposed uses of aminocyclopyrachlor includes:

Aminocyclopyrachlor at a glance

Proposed uses of aminocyclopyrachlor includes:– Total vegetation management (Non-agricultural areas) – brush control on private public and military lands– Natural or wildlife management areas– Restoration on native perennial grasses– Professional turf fields– Pasture & rangeland areas

Objectives

• Investigate PRE, POST and POST-directed applications ofaminocyclopyrachlor and/or aminocyclopyrachlor-methylalone and in combinations with other herbicides forbroadleaf weed control and curcurbit crop tolerance

Objectives

broadleaf weed control and curcurbit crop tolerance.

• Compare these multiple herbicide mixtures to commercialstandards (i.e. clomazone + ethalfluralin, halosulfuron, etc.)

• Evaluate weed control potential of these herbicide mixturesat different timings of application.

Materials &

Methods

• A total of four field studies were conducted in latespring to fall of 2009 at The University ofTennessee Plateau Research and Education

Materials & Methods

Tennessee Plateau Research and Educationcenter in Crossville, Tennessee.

P l a t e a u R e s e a r c h & E d u c a t i o n C e n t e r

A g R e s e a r c h 320 Experiment Station Road

Crossville, TN 38571

Evaluation of POST-directed applications of aminocyclopyrachlor-methyl alone and in mixtures with halosulfuron and naptalam for weed control in pumpkin.

PRE selectivity of the auxin herbicide aminocyclopyrachlor-methyl, the ALS-inhibitor halosulfuron & the PPO-inhibitor

fomesafen to a variety of cucurbit crops.

Evaluation of PRE applications aminocyclopyrachlor-methyl alone and in mixtures with clomazone, halosulfuron, naptalam

and ethalfluralin for PRE weed control in pumpkin.

Evaluation of crop safety to aminocyclopyrachlor-methyl and aminocyclopyrachlor applied POST over the top in pumpkins

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Common ragweed Ambrosia artemisiifoliaSmooth groundcherry Physalis subglabrata

Ladysthumb Polygonum persicaria

Weeds Evaluated

y yg p

Yellow nutsedge Cyperus esculentus

Ivyleaf morningglory Ipomoea hederacea

Common purslane Portulaca oleracea

Large crabgrass Digitaria sanguinalis

# Herbicide Treatment Application Rate (s)

First study:PRE selectivity of the auxin herbicide aminocyclopyrachlor-methyl, the ALS-inhibitor halosulfuron & the PPO-inhibitor fomesafen to a variety of

cucurbit crops.

1 aminocyclopyrachlor-methyl 9 g ai/ha2 aminocyclopyrachlor-methyl 18 g ai/ha 3 aminocyclopyrachlor-methyl 35 g ai/ha 4 aminocyclopyrachlor-methyl 70 g ai/ha 5 halosulfuron 40 g ai/ha6 fomesafen 280 g ai/ha7 Handweeded Untreated Check

Pumpkin Curcubita pepovar. magic lantern

Crops Evaluated

Cucumber Cucumis sativavar. speedway

Watermelon Citrullus lanatusvar. crimson sweet

Cantaloupe Cucumis melovar. aphrodite

# Herbicide Treatment Application Rate (s)1 aminocyclopyrachlor-methyl 18 g ai/ha

2 aminocyclopyrachlor-methyl 35 g ai/ha

3 aminocyclopyrachlor-methyl + ethalfluralin 18 g ai/ha / 1680 g ai/ha

4 aminocyclopyrachlor-methyl + ethalfluralin 35 g ai/ha / 1680 g ai/ha

Second study:Evaluation of PRE applications aminocyclopyrachlor-methyl alone and in mixtures with clomazone, halosulfuron, naptalam and ethalfluralin for

PRE weed control in pumpkin.

5 aminocyclopyrachlor-methyl + clomazone 18 g ai/ha / 420 g ai/ha

6 aminocyclopyrachlor-methyl + clomazone 35 g ai/ha / 420 g ai/ha

7 aminocyclopyrachlor-methyl + clomazone + ethalfluralin 18 g ai/ha / 420 g ai/ha / 1680 g ai/ha

8 aminocyclopyrachlor-methyl + clomazone + ethalfluralin 35 g ai/ha / 420 g ai/ha / 1680 g ai/ha

9 aminocyclopyrachlor-methyl + naptalam 18 g ai/ha / 1120 g ai/ha


11 aminocyclopyrachlor-methyl + naptalam + ethalfluralin 18 g ai/ha / 1120 g ai/ha / 1680g ai/ha

12 aminocyclopyrachlor-methyl + naptalam + ethalfluralin 35 g ai/ha / 1120 g ai/ha / 1680 g ai/ha

13 ethalfluralin + clomazone 1680 g ai/ha / 420 g ai/ha

14 ethalfluralin + naptalam 1680 g ai/ha / 1120 g ai/ha

15 ethalfluralin + halosulfuron 1680 g ai/ha / 40 g ai/ha

16 ethalfluralin 1680 g ai/ha

17 Untreated Control -


2 aminocyclopyrachlor-methyl 35 g ai/ha

3

Third Study:Evaluation of POST-directed applications of aminocyclopyrachlor-methyl alone and in mixtures with halosulfuron and naptalam forweed control in pumpkin.

Note: *all treatments included non ionic surfactant at .25% v/vand ethalfluralin applied PRE at 1680 g ai/ha





7 aminocyclopyrachlor-methyl + halosulfuron 18 g ai/ha / 26 g ai/ha




11 naptalam 560 g ai/ha

12 naptalam 1120 g ai/ha

13 halosulfuron 26 g ai/ha

14 halosulfuron 53 g ai/ha

15 ethalfluralin 1680 g ai/ha

16 Untreated Control -


Fourth Study:Evaluation of crop safety to aminocyclopyrachlor-methyl and aminocyclopyrachlor applied POST over the top in pumpkins.

Note: *all treatments contained ethalfluralin applied PRE at 1680 g ai/ha

1 aminocyclopyrachlor methyl 18 g ai/ha2 aminocyclopyrachlor-methyl 35 g ai/ha 3 aminocyclopyrachlor 18 g ai/ha 4 aminocyclopyrachlor 35 g ai/ha 5 Untreated Check

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Results & Discussion

First Study:PRE selectivity of the auxin herbicide

i l hl th l th ALSaminocyclopyrachlor-methyl, the ALS-inhibitor halosulfuron & the PPO-inhibitor fomesafen to a variety of

cucurbit crops.

% I

njur

y

10

15

20

25

30

35

14 DATPreemergence selectivity on cucurbit crops

%

0

5

10

pump watermelon cucumber cantaloupe(LSD=15.9) (LSD=22.1) (LSD=19.8) (LSD=10.6)

% I

njur

yPreemergence selectivity on cucurbit crops

8

10

12

14

16

18

20

56 DAT%

(LSD=15.9) (LSD=22.1) (LSD=19.8) (LSD=10.6)

0

2

4

6

pump watermelon cucumber cantaloupe

g / p

lot

Preemergence selectivity on cucurbit crops

40

50

60

70

80

90

100

Yield

K

(LSD=85.1) (LSD=57.9) (LSD=39.4)

0

10

20

30

pump watermelon cucumber

Second Study:Evaluation of PRE applications

aminocyclopyrachlor-methyl alone and y py yin mixtures with clomazone,

halosulfuron, naptalam and ethalfluralin for PRE weed control in pumpkin.

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Injury to pumpkin from PRE applications ofaminocyclopyrachlor-methyl alone and in mixturesclomazone, halosulfuron, naptalam and ethalfluralin.

ury

56 DAT

15

20

13 12 13 1315

Pumpkin

% In

j

(LSD=14.2)

0

5

10

0

7 7 7

10

0

Pumpkin

PRE applications aminocyclopyrachlor-methyl alone andin mixtures with clomazone, halosulfuron, naptalam andethalfluralin for PRE weed control in pumpkin.

Con

trol 56 DAT

50

60

70

80

90

100

75

42

% C

(LSD=22)

0

10

20

30

40

8

3022

13

2

32

3

15

0

morningglory

PRE applications aminocyclopyrachlor-methyl alone andin mixtures with clomazone, halosulfuron, naptalam andethalfluralin for PRE weed control in pumpkin.

Con

trol 56 DAT

50

60

70

80

90

100

6053

% C

(LSD=16)

0

10

20

30

40

50

28 3037

28

1823

2822

0

smooth groundcherry

PRE applications aminocyclopyrachlor-methyl alone andin mixtures with clomazone, halosulfuron, naptalam andethalfluralin and their impact on pumpkin yield.

/ plo

t

10

12

14

16

18

20

13.5

8 5

95 DAT

Kg

(LSD=5.8)

0

2

4

6

8

10

3.12.3

5.3 5.8

8.5

6.65.2

2

7.7

3.4

Pumpkin Yield

Third Study:Evaluation of POST-directed

li ti f i l hlapplications of aminocyclopyrachlor-methyl alone and in mixtures with

halosulfuron and naptalam for weed control in pumpkin.

Evaluation of POST-directed applications ofaminocyclopyrachlor-methyl alone and in mixtures withhalosulfuron and naptalam for weed control in pumpkin.

Con

trol

50

60

70

80

58

67

78

6863

38

50

% C

(LSD=23.5)

0

10

20

30

40

22

10

0

common ragweed

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Evaluation of POST-directed applications ofaminocyclopyrachlor-methyl alone and in mixtures withhalosulfuron and naptalam for weed control in pumpkin.

Con

trol

5060708090

87

5547 48

% C

(LSD=43.8)

010203040

0

27

0 0 0 0

yellow nutsedge

Fourth Study:Evaluation of crop safety to p y

aminocyclopyrachlor-methyl and aminocyclopyrachlor applied POST over

the top in pumpkins.

Evaluation of aminocyclopyrachlor-methyl and aminocyclopyrachlor application POST over the top in

pumpkins.14, 28 & 56 DAT

23

27

20

25

30

aminocyclopyrachlor-methyl LR

% In

jury

(LSD=5) (LSD=8) (LSD=5.8)

20

0

5

10

15

20

14 28 56

aminocyclopyrachlor-methyl HR

aminocyclopyrachlor LR

aminocyclopyrachlor HR

Untreated Check

Symptomology expressed by aminocyclopyrachlor-methyl applied

POST over the top in pumpkins.

Aminocyclopyrachlor-methyl

18 g ai/ha

Aminocyclopyrachlor-methyl

35 g ai/haUntreated Check

Symptomology expressed by aminocyclopyrachlor applied POST over

the top in pumpkins.

Aminocyclopyrachlor18 g ai/ha

Aminocyclopyrachlor35 g ai/ha Untreated Check

Conclusion

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• Aminocyclopyrachlor-methyl applied alone at 9 to 70 g ai/haPRE was safe to pumpkin (2 years of research). Cucumber,cantaloupe, and watermelon injury is often unpredictableover rates and years. However, all cucurbits have providedsimilar yields compared to halosulfuron, fomesafen and theuntreated check

Conclusion

untreated check.

• The combination of the auxin mimic herbicideaminocyclopyrachlor-methyl plus the auxin transportinhibitor naptalam provided a “synergistic improvement” inpumpkin yield over either herbicide applied alone

• Aminocyclopyrachlor-methyl applied POST at 35 g ai/haone or in mixtures with naptalam or halosulfuron provided58 to 93% control of common ragweed and smoothgroundcherry in comparison compared to 10 to 50%control with naptalam or halosulfuron applied alone.A i l hl th l i t ith t l• Aminocyclopyrachlor-methyl mixtures with naptalamprovided 60 to 93% control of ivyleaf morningglory.

• Mixtures of aminocyclopyrachlor-methyl plus halosulfuronprovided 55 to 87% control of yellow nutsedge versus 47to 48% control with halosulfuron alone.

• Aminocyclopyrachlor was slightly less injurious in POSTover the top applications on pumpkins compared to itsester formulation.

S p e c i a l T h a n k s

http://hortweeds.tennessee.edu

Weed Management in Pumpkins Weed Identificationvegetables.tennessee.edu/pdfs/Pumpkin Weed...

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