Squash Tolerance to Sandea Squash Tolerance to Sandea and Applying Sandea Through and Applying Sandea Through

Drip TapeDrip Tape

Dr. Ted WebsterDr. Ted Webster

Weed ScientistWeed Scientist

USDA-ARSUSDA-ARS

Tifton, GATifton, GA

Purple and Yellow Nutsedges:Purple and Yellow Nutsedges:Primary Weeds Primary Weeds

in a Plasticulture Systemin a Plasticulture System

What Did We Want What Did We Want to Find Out?to Find Out?

• Will Sandea injure squash?Will Sandea injure squash?

• Does application method matter?Does application method matter?

• What kind of nutsedge control can we What kind of nutsedge control can we expect?expect?

Greenhouse StudyGreenhouse Study

• Squash cultivars:Squash cultivars:– 3 zucchini3 zucchini

– 2 yellow crookneck2 yellow crookneck

– 1 yellow straightneck1 yellow straightneck

• Rates of Sandea:Rates of Sandea:– 0.33 oz/A0.33 oz/A

– 0.66 oz/A0.66 oz/A

– 1.00 oz/A1.00 oz/A

• Application Methods:Application Methods:– PRE PRE

– POSTPOST

– SplitSplit

• Planting Methods:Planting Methods:– TransplantsTransplants

– Direct SeededDirect Seeded

Visual Squash Injury (32 DAP)Visual Squash Injury (32 DAP)

SandeaSandea ____ Direct Seeded Direct Seeded ____ ________ Transplant Transplant ________

(oz/A)(oz/A) PREPRE POSTPOST SplitSplit PREPRE POSTPOST SplitSplit

______________________ % Visual Crop Injury % Visual Crop Injury ______________________

0.330.33 15 c15 c 13 c13 c 15 c15 c 14 c14 c 13 c13 c 13 c13 c

0.660.66 23 b23 b 17 bc17 bc 22 b22 b 17 bc17 bc 12 c12 c 15 c15 c

1.001.00 35 a35 a 19 bc19 bc 33 a33 a 17 bc17 bc 17 bc17 bc 13 c13 c

32 DA-PRE, 16 DA-POST

* *

Sandea Applied PRE to Sandea Applied PRE to Direct-Seeded Zucchini Direct-Seeded Zucchini

Squash (Tigress)Squash (Tigress)

0.33 oz/A

1.0 oz/A Nontreated Control

Visual Squash Injury (32 DAP)Visual Squash Injury (32 DAP)

Squash CultivarSquash Cultivar Direct SeededDirect Seeded TransplantTransplant______ % Visual Crop Injury % Visual Crop Injury ______

Dixie (cn)Dixie (cn) 20 c-e20 c-e 18 c-g18 c-g

Lemondrop (sn)Lemondrop (sn) 18 c-f18 c-f 13 g-l13 g-l

Senator (z)Senator (z) 17 c-h17 c-h 14 f-k14 f-k

Spineless Beauty (z)Spineless Beauty (z) 24 ab24 ab 13 h-l13 h-l

Supersett (cn)Supersett (cn) 28 a28 a 13 h-l13 h-l

Tigress (z)Tigress (z) 21 bc21 bc 15 e-i15 e-i *

*

*

*

60 Lb. Pressure Valve

Air Relief Valve

Backflow Valve

Low Pressure

Drain

Filter

Pressure Regulator (20 lb)

DRIP TAPE INJECTION SYSTEMTifton, GA

Pump (125 ml/min)Field Studies

Treatments (Applied 14 days prior to transplanting/seeding)

• Metam (75 gal/A)

• Non-treated: Black Plastic mulch

• Non-treated: Bareground

• Sandea (PRE) – prior to laying plastic

• Sandea (Drip) – applied through Drip Tape– 0.75 oz/A in 1 gal. of water, injected for 30 min.– Flush system for 1 hour

Webster 2000 & 2001

Field Study: Field Study: Crop and Weed ResponsesCrop and Weed Responses

CropCrop Nutsedge(shoots/plot)Nutsedge(shoots/plot)

TreatmentTreatment Diameter (cm)Diameter (cm) Early SeasonEarly Season Late SeasonLate Season

Sandea:DripSandea:Drip 47*47* 2*2* 28*28*

Sandea:PRESandea:PRE 45*45* 4*4* 38*38*

Metam Metam 58 58 1*1* 27*27*

Non-treatedNon-treated 49*49* 15*15* 113113

BaregroundBareground 42*42* 7171 ______

PLSDPLSD0.050.05 77 1616 5252

Metam Sandea PRE

Sandea: Drip Nontreated

Bare GroundNontreated

Field Study: Total Crop Yields (lbs/plot)Field Study: Total Crop Yields (lbs/plot)

20002000 20012001

TransplantTransplant SeededSeeded TransplantTransplant SeededSeeded

Sandea:DripSandea:Drip 3131 34*34* 7575 58*58*

Sandea:PRESandea:PRE 25*25* 32*32* 62*62* 51*51*

Metam Metam 37 37 4242 8989 7878

Non-treatedNon-treated 28*28* 27*27* 67*67* 55*55*

BaregroundBareground 1111 11 4545 3737

PLSDPLSD0.050.05 ________________ 8 8 ________________ ____________________ 16 16 __________ __________

Culpepper 2001

Culpepper 2001

PREPRE

20 DAE20 DAE 30 DAE30 DAE

10 DAE10 DAE

ConclusionsConclusions

• Sandea caused early season squash injury.Sandea caused early season squash injury.

• Variable response of squash to Sandea:Variable response of squash to Sandea:– Greenhouse: Early growth of transplanted Greenhouse: Early growth of transplanted

squash more tolerant of Sandea than direct-squash more tolerant of Sandea than direct-seeded squash.seeded squash.

– Field: Differences among planting methods in Field: Differences among planting methods in response to Sandea were not detected in terms of response to Sandea were not detected in terms of crop yield.crop yield.

– Field: Older/larger plants appear to be more Field: Older/larger plants appear to be more tolerant of Sandea applications.tolerant of Sandea applications.

ConclusionsConclusions

• Preliminary: similar nutsedge Preliminary: similar nutsedge suppression from: Metam (75 gal/A) and suppression from: Metam (75 gal/A) and Sandea (0.75 oz/A); Is tuber population Sandea (0.75 oz/A); Is tuber population affected? affected?

• Early season: 80% fewer nutsedge shoots Early season: 80% fewer nutsedge shoots in black plastic UTC vs. bareground in black plastic UTC vs. bareground UTCUTC

What’s next?What’s next?Future research questionsFuture research questions

• Will Sandea through drip tape kill Will Sandea through drip tape kill emerged nutsedge ?emerged nutsedge ?

• Will cucurbits tolerate Will cucurbits tolerate POSTPOST Sandea Sandea applications through drip tape?applications through drip tape?

• How many purple nutsedge does it take How many purple nutsedge does it take to reduce squash yields?to reduce squash yields?

AcknowledgementsAcknowledgements

• We acknowledge the technical skills and We acknowledge the technical skills and efforts of James Davis in coordinating efforts of James Davis in coordinating these studies.these studies.

• We also thank Eddie Sklany and the We also thank Eddie Sklany and the numerous student workers for their numerous student workers for their assistance in plot establishment and assistance in plot establishment and harvest.harvest.

• This work was supported in part by the This work was supported in part by the IR-4 Minor-Use Crops Research Project.IR-4 Minor-Use Crops Research Project.