Weed Management in Cucurbits

Curcurbits

• Select Max

• Sinbar

• Alanap

• Sandea

• Curbit

• Herbicide/Mulch relations

What’s New - Select Max

• clethodim – Registered 2006– Select Max 0.97 EC

– Apply twice the rate of Select 2 EC– For Cantaloupe, Cucumber, Squash, and

Watermelon use 12-16 fl oz/A

– Label allows for use of NIS instead of COC

Sinbar - Watermelon

2 to 3 oz of product applied preemergence

Seeded: make applications after planting but before the crop emergence

Transplants: Apply prior to transplant on bareground. May apply over mulch but ½ inch rainfall must occur following applications.

Now owned by Tessenderlo Kerley, Inc

Sinbar – watermelon injury and pigweed control

0102030405060708090

100

%

2 wk 5 wk

1.5 oz 3.0 oz

Watermelon

InjuryPigweed

Control

Palmer Amaranth Control8 WAT

0102030405060708090

100

Co

ntr

ol

(%)

&&

Curbit + Sinbar 3oz + Sinbar 6oz

Mulch

No Mulch

Yellow Nutsedge Control8 WAT

0102030405060708090

100

Co

ntr

ol

(%)

&&

Curbit + Sinbar 3oz + Sinbar 6oz

Mulch

No Mulch

Watermelon Harvest(Total Weight) 1000 lbs/A

0102030405060708090

100

To

tal

Wei

gh

t

&&

Curbit + Sinbar 3oz + Sinbar 6oz

Mulch

No Mulch

Curbit 1.5 pt/A PRE

Curbit 1.5 pt/A + Sinbar 2.5 oz

Curbit 1.5 pt/A + Sinbar 6 oz

Summary - Watermelon

Sinbar at 3 oz/A provided control of:a) Palmer amaranth = 78-89%

b) Yellow nutsedge = 26-44%

c) Tropic croton = 72-88%

Sinbar at 6 oz/A provided control of:a) Palmer amaranth = 95-97%

b) Yellow nutsedge = 78-80%

c) Tropic croton = 97%

Cantaloupe – Sinbar• Mulch and Bareground All plots received

• Treatments (Sinbar applied pre-transplant)

– 1) Curbit @ 1 qt/A– 2) Curbit @ 1 qt/A + Sinbar @ 3 oz/A– 3) Curbit @ 1 qt/A + Sinbar @ 6 oz/A

Cantalope Injury5 WAT

0102030405060708090

100

Inju

ry (

%)

&&

Curbit + Sinbar 3oz + Sinbar 6oz

Mulch

No Mulch

Cantaloupe Runner Length5 WAT

0102030405060708090

100

Len

gth

(cm

)

&&

Curbit + Sinbar 3oz + Sinbar 6oz

Mulch

No Mulch

Summary

Bareground Production

- Not a chance

Mulch Production

- Sinbar did not injury cantaloupe 5 WAT

- Sinbar at 6 oz/A reduced runner length 10%, 5 WAT

Sinbar Carryover

• There are carryover issues after an application of Sinbar most notably the cole and greens crops.

• Sinbar– The label states “Do not replant treated areas

to any crop within 2 years after last application as injury to the subsequent crop(s) may result.”

Sinbar Watermelon

CARRYOVER RESEARCH IN PROGRESS

Label is very restrictive; UGA preliminary results:

< 10% damage: sweet corn, squash, wheat, oat, rye, snap bean

1X rate 10 to 40% damage: cabbage, kale, broccoli, collard

2X rate: 40 to 80% damage: cabbage, kale, broccoli, collard

Alanap Going Away – Spring 2008

Chemtura voluntarily canceling registration

Production was stopped Oct. 2007

50,000 gal inventory

2.5 years of inventory if normal use continues

Shelf life is about 3 years

common ragweed chickweed

common cocklebur purslane

common lambsquarters white mustard

pigweeds smartweeds

Alanap: Weeds Controlled

Production of this herbicide has ceased; 2 yrs of inventory

Non-treated

Curbit Curbit followed by Alanap

Sandea

• PRE/POST to crop: cucumber and cantaloupe

• Row middle only: squash

• PRE and row middle: watermelon

Sandea Labeled for Watermelon

1) PREEMERGENCE: 0.75 oz/A

Seeded: Apply after planting, before cracking

Transplant bareground/mulch: Do not transplant

till 7 d after application.

*Avoid heavy rain right after application

*DO NOT APPLY OVER MULCH and then transplant.

Nontreated Sandea (0.5 oz/A)

Watermelon farm in Crisp County, May 2000. Treatment at 1-leaf. Pictures to scale.

Sandea for PRE Weed Control

common cocklebur

wild radish

pigweeds

common ragweed

common lambsquarters

yellow nutsedge - suppression purple nutsedge - suppression

2 to 3 weeks residual weed control

Non-treated Control Sandea (0.5 oz/A) PRE

W1-00. Halosulfuron study with Ken Lewis in Cordele.

Sandea PRE

No herbicide

Sandea for POST Weed Control

1-3 inch 1-9 inch

passionflower cocklebur

redroot pigweed ragweed

pokeweed velvetleaf

yellow and purple nutsedge – heavy infestations may require sequential applications

2 to 3 weeks residual weed control

Curbit

1. Curbit is labeled for many cucurbits, Sonalan is not

Curbit

1. Curbit is labeled, Sonalan is not

2. Do not apply under mulch

Cucumber Injury from Curbit

Over mulch, washed off Under mulch

Over mulch, washed off Under mulch

Recommend 1 pt if seeded bareground.

If not contacting the crop (row middle or mulch) can go up to 3 pts

0

20

40

60

80

100

0 1 2 3 4 5

washed

no washed

Amount of Curbit remaining on plastic mulch. TyTy GA, 2005.

perc

ent

daysGrey

Herbicide/Mulch Relations

0

20

40

60

1 2 3 4 5

no wash

washed

Amount of paraquat remaining on plastic mulch. TyTy GA, 2005.

perc

ent

daysGrey

0

20

40

60

80

100

1 2 3 4 5

no wash

washed

Amount of glyphosate remaining on plastic mulch. TyTy GA, 2005.

perc

ent

daysGrey

Halosulfuron dissipation on mulch

Event

0 1 2 3 4 5

hal

osu

lfu

ron

ret

ain

ed (

%)

0

20

40

60

80

100

% halosulfuron Dry % halosulfuron Wash off

65%

6%

Non-treatedSandea prior to transplant

Aim dissipation from mulch

Harvest event

0 1 2 3 4 5

ca

rfen

tra

zon

e r

eta

ine

d (

%)

0

20

40

60

80

100

% carfentrazone Dry

% carfentrazone Wash off

New Herbicide for Watermelons – 2010?

Preplant or PRE application of Reflex

SEVERE INJURY IF APPLIED TO EMERGED PLANTS

Percent watermelon injury from Reflex.

Bareground System.

0

5

10

15

20

25

30

Loc 1, 2002

Loc 2, 2003

Loc 3, 2003

Loc 4, 2004

Loc 5, 2006

Loc 6, 2007

Reflex pre-transplant applied 16 oz/A.

Percent watermelon injury from Reflex.

Mulched System.

0

20

Loc 1, 2003

Loc 2, 2006

Loc 3, 2007

Reflex applied 16 oz/A over mulch. Half inch irrigation prior to transplant.

Carryover from Reflex applied under mulch. Crops planted 6 months later. 2007

0

20

40

60

80

100

Seeded cucumber Transplant cucumber Seeded squash

Transplant squash Seeded collard Transplant collard

Transplant cabbage Transplant broccoli Sweet corn

% in

jury

Comments or Questions?