Post on 02-Jan-2016
description
Should I Stay or Should I Grow? The nutsedge dilemma in polyethylene
mulch systems
Theodore M. WebsterCrop Protection and Management
Research Unit
USDA-ARS, Tifton, GA
Low-Density PolyethyleneMulch is a Great PhysicalWeed Control Barrier…
Low-Density PolyethyleneMulch is a Great PhysicalWeed Control Barrier…
…In the Absenceof Methyl Bromide,
Mulch Will Be aCritical Component
of WeedManagement
Systems
…ButNutsedgesWill Pierce
ThisPhysicalBarrier
andInterfere
WithCrop
Growth
X X X
… 40 Acre Watermelon FieldWithout Methyl Bromide Treatment
Hypotheses:
• Polyethylene mulch will hinder nutsedge shoot growth, tuber production, and patch expansion
• Purple and yellow nutsedge will be affected by mulches in a similar manner
• Purple and yellow nutsedge will have similar growth habits in the absence of mulches.
Black MulchBlack Mulch
Clear MulchClear Mulch
No-MulchNo-Mulch
Temporal Patterns of EmergenceTemporal Patterns of Emergence
• 16 Wks• 59 cm Diam.• 23 cm Deep• 1.25 mil• Drip Irrigation
Black Mulch Clear Mulch No Mulch
Nu
tsed
ge
Sh
oo
t E
mer
gen
ce (
No
. per
po
t)
0
20
40
60
80
100
120
140
160
Purple NutsedgeYellow Nutsedge
A
B
BBBB
Nutsedge Shoots/Potby mulch and species
146
15
6 2
Previous Studies:Nutsedge Population With and Without Black LDPE Mulch
Purple Nutsedge Growing Under Black LDPE – Minimal Shoot Penetration Through The Mulch(shoots growing under black mulch in previous slide)
…So we evaluated nutsedge shoot numberstrapped beneath mulch in the greenhouse study
Black Mulch Clear Mulch
Nu
tsed
ge
Sh
oo
t P
op
ula
tio
n B
elo
w M
ulc
h (
No
. per
po
t)
0
20
40
60
80
Purple NutsedgeYellow Nutsedge
B
C
A
C
Nutsedge Shoots/Pot Below Mulchby mulch and species
73
39
14 12
58% 92% 80% 95%
Soil Sieved for tubersSoil Sieved for tubers
Black Mulch Clear Mulch No Mulch
Nu
tsed
ge
Tu
ber
Pro
du
ctio
n (
No
. per
po
t)
0
100
200
300
400
Purple NutsedgeYellow Nutsedge
A
C
B
C
B
C
Nutsedge Tubers/Potby mulch and species
366
188179
47
How does mulch affect nutsedgepatch expansion in the field?
Purple NutsedgePurple Nutsedge
Black PlasticBlack Plastic
Clear PlasticClear Plastic
No PlasticNo Plastic
There were differences due to mulch!
12.7 cm12.7 cm12.7 cm12.7 cm
Grid System Used To Quantify Yellow Nutsedge And Purple Nutsedge
(<16 WAP) Shoot Populations
Grid System (12.7 cm X 12.7 cm) Used To Quantify Purple Nutsedge Shoot Populations After 8 WAP
12.712.7cmcm
Unable To Evaluate Purple Nutsedge In Clear Mulch:This Is The Only Plot That Survived Establishment
Time (weeks after planting)
0 10 20 30 40 50 60
Pu
rple
nu
tsed
ge
sho
ots
(#/
pat
ch)
0
500
1000
1500
2000
2500
3000
3500Non-mulchedBlack mulch
Purple Nutsedge Shoots/Patch
1548
794
3439
1858
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
stin
g (
cm
)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
16 Weeks After PlantingPurple Nutsedge
Non-Mulched Control
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
24 Weeks After PlantingPurple Nutsedge
Non-Mulched Control
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
32 Weeks After PlantingPurple Nutsedge
Non-Mulched Control
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
60 Weeks After PlantingPurple Nutsedge
Non-Mulched Control
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
16 WAP 24 WAP
32 WAP 60 WAPPurple Nutsedge
Non-Mulched Control
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
16 Weeks After PlantingPurple Nutsedge
Black LDPE Mulch
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
24 Weeks After PlantingPurple Nutsedge
Black LDPE Mulch
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
32 Weeks After PlantingPurple Nutsedge
Black LDPE Mulch
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
60 Weeks After PlantingPurple Nutsedge
Black LDPE Mulch
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
16 WAP 24 WAP
32 WAP 60 WAPPurple Nutsedge
Black LDPE Mulch
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
stin
g (
cm
)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
stin
g (
cm
)2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
32 Weeks After Planting
Purple NutsedgeNon-mulched control
Purple NutsedgeBlack LDPE Mulch
0 100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
sti
ng
(c
m)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
100 200 300 400 500
Northing (cm )
0
100
200
300
400
500
600
700
Ea
stin
g (
cm
)2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
60 Weeks After Planting
Purple NutsedgeNon-mulched control
Purple NutsedgeBlack LDPE Mulch
Time (weeks after planting)
0 10 20 30 40 50 60
Pu
rple
nu
tsed
ge
pat
ch a
rea
(m2/p
atch
)
0
5
10
15
20
25
Non-mulchedBlack mulch
Purple Nutsedge Patch Area
16.1
8.1
22.1
11.6
Yellow Nutsedge: a different growth patternYellow Nutsedge: a different growth pattern
Black PlasticBlack Plastic
Clear PlasticClear Plastic
No PlasticNo Plastic
Yellow nutsedge was sensitive to cool autumn temperatures,therefore there is no data beyond 24 WAP
Yellow Nutsedge Shoots/Patch
Time (weeks after planting)
0 8 16 24
Yel
low
nu
tsed
ge
sho
ots
per
pat
ch
0
50
100
150
200
250
Black mulchNon-mulched controlClear mulch
208
73 & 76
36 & 39
137
0 20 40 60 80 100 120
Northing (cm)
0
20
40
60
80
100
120
Eas
tin
g (
cm)
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
Yellow Nutsedge Yellow Nutsedge Patch Expansion:Patch Expansion:24 Weeks of growth 24 Weeks of growth from a single tuberfrom a single tuber
Patch Area: 0.18 mPatch Area: 0.18 m22
177 Yellow Nutsedge Shoots177 Yellow Nutsedge Shoots
Time (weeks after planting)
0 8 16 24
Nu
mb
er o
f q
uad
rats
per
pat
ch
wit
h y
ello
w n
uts
edg
e sh
oo
ts
0
2
4
6
8
10
12
Black mulchNon-mulched controlClear mulch
Number of Yellow Nutsedge Quadrats/Patch
11.0 (0.18 m2)
9.3
5.3
0 50 100 150 200 250
Northing (cm )
0
50
100
150
200
250
300
350
400
450
500
Eas
tin
g (
cm)
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
0 50 100 150 200 250
Northing (cm )
0
50
100
150
200
250
300
350
400
450
500
Eas
tin
g (
cm)
2 0
6 0
1 0 0
1 4 0
1 8 0
2 2 0
2 6 0
3 0 0
3 4 0
3 8 0
4 2 0
4 6 0
5 0 0
5 4 0
5 8 0
6 2 0
24 WAPNon-mulched controls
Yellow nutsedge Purple nutsedge
0.18 m2 5.5 m2
Conclusions: GreenhouseConclusions: Greenhouse
• Non-mulched control: Relative to Purple Non-mulched control: Relative to Purple Nutsedge, Yellow Nutsedge produced:Nutsedge, Yellow Nutsedge produced:– 9x’s more shoots 9x’s more shoots – 7x’s more tubers 7x’s more tubers
• Mulches: Reduced Yellow Nutsedge Mulches: Reduced Yellow Nutsedge – Shoot #’s by 96%Shoot #’s by 96%– Tuber #’s by 50%Tuber #’s by 50%– Differences in purple nutsedge shoot #’s Differences in purple nutsedge shoot #’s
and tuber #’s could not be detected among and tuber #’s could not be detected among treatmentstreatments
Conclusions: FieldConclusions: Field
• Purple Nutsedge in Black Mulch Plots:Purple Nutsedge in Black Mulch Plots:– 2x’s MORE shoots at 32 and 60 WAP 2x’s MORE shoots at 32 and 60 WAP
compared to Non-Mulched Controlcompared to Non-Mulched Control– 2x’s MORE patch area at 32 and 60 WAP 2x’s MORE patch area at 32 and 60 WAP
compared to the Non-Mulched Controlcompared to the Non-Mulched Control
• Yellow Nutsedge in Black Mulch Plots:Yellow Nutsedge in Black Mulch Plots:– 3x’s LESS shoots at 16 and 24 WAP 3x’s LESS shoots at 16 and 24 WAP
compared to Non-Mulched Controlcompared to Non-Mulched Control– 2x’s LESS patch size (in terms of quadrat 2x’s LESS patch size (in terms of quadrat
#’s) compared to Non-Mulched Control#’s) compared to Non-Mulched Control
Take Home Message:Take Home Message:• Yellow Nutsedge:Yellow Nutsedge:
– Growth SUPPRESSED by black mulchGrowth SUPPRESSED by black mulch– Does not distribute itself far from the mother Does not distribute itself far from the mother
tubertuber– Confirms the predictions of a spatial model of Confirms the predictions of a spatial model of
yellow nutsedge growth: farming operations are yellow nutsedge growth: farming operations are the main cause of yellow nutsedge dispersal in the main cause of yellow nutsedge dispersal in the field (Schippers et al. 1993).the field (Schippers et al. 1993).
• Purple nutsedge:Purple nutsedge:– Growth PROMOTED by black mulchGrowth PROMOTED by black mulch– Well suited to distribute itself through its Well suited to distribute itself through its
environment.environment.
Acknowledgements Acknowledgements
Contact Information:
Twebster@tifton.usda.gov
http://www.cpes.peachnet.edu/cpmru/
http://gaweed.com
• Eddie Sklany (Study Coordinator)• Aaron Wise• Dustin Taylor• John Bennet• Amy Davis• Stefanie Cross