sedge biology and control in warm-season turf tim r. murphy the university of georgia

Sedge Biology and Control in Sedge Biology and Control in Warm-Season TurfWarm-Season Turf

Tim R. MurphyTim R. Murphy

The University of GeorgiaThe University of Georgia

Taxonomy of Sedges

Order – Graminales Class – Angiospermae Subclass – Monocotyledoneae Family – Cyperaceae (grasses are in Poaceae) Problem Genera – Cyperus and Kyllinga

Purple Nutsedge – Cyperus rotundus Introduced, native to Eurasia S. East U.S., CA and AZ Ranked world’s worst weed Forms chains of

interconnected tubers Prefers medium to fine-

textured soils Highly adapted to compacted

soils

Yellow Nutsedge – Cyperus esculentus

Native to North America Found in all of U.S. Ranked 16th worst weed

in world Forms tubers Commonly found in

sandy soils Thrives in non-compacted

soils

Other Key Differences

How do nutsedges reproduce?

Seed - ?????– Research indicates seed production and viability is

very low

Tubers– The primary method of reproduction– Numerous buds per tuber

Yellow Nutsedge Tuber Biology

Begin to form at tips of rhizomes 4 to 6 weeks after plant emerges

80% located in top 6 inches of soil Counts as high as 4 to 12 million/acre Shade will decrease tuber production

Yellow Nutsedge Tuber Longevity

Longer as tuber burial depth increases 4 month half-life at 4 inches 6 month half-life at 8 inches 3 consecutive yrs of control reduced tuber density

85% In SC, 200,000 tubers/ac remained after 4

consecutive yrs of > 90% control in bermudagrass

Tuber Sprouting

Buds form new shoots

Yellow – 54 F.

Purple – 68 F.

Kyllinga species

Sedge family Annuals – seed Perennials - seed and rhizomes No tuber formation Thrive in wet soils Increasing in severity Lack of MSMA use??

Green (perennial) kyllinga

Sedge & Kyllinga Herbicides Basagran T/O - yellow, annual sedges, kyllinga Manage - yellow, purple, annual sedges, kyllinga Monument - yellow, purple, annual sedges,

kyllinga Katana & Battalion – in development MSMA/DSMA - yellow, purple, annual sedges,

kyllinga Image - yellow, purple, annual sedges, kyllinga Pennant - yellow, annual sedges & annual kyllinga

Research Data

Purple nutsedge (Cyperus rotundus)

Yellow nutsedge (Cyperus esculentus)

False green kyllinga (Kyllinga gracillima)

(Appreciation is extended to Dr. Fred Yelverton, NCSU for use of data slides)

Purple Nutsedge (Cyperus rotundus) Control

0

20

40

60

80

100

6 WAIT

% C

ontr

ol

Monument .35 oz

Monument .59 oz

Monument .35 oz +Bueno 6 1.33pt

Manage 1.27 oz

Image 2.67 pt

Rates are per acre. Trial initiated 6-21. Sequential applied 8-2.

91b

99a

85c

74d 74d

Purple Nutsedge (Cyperus rotundus) Control

0

20

40

60

80

100

14 WAIT

% C

ontr

ol

Monument .35 oz

Monument .59 oz

Monument .35 oz +Bueno 6 1.33pt

Manage 1.27 oz

Image 2.67 pt

Rates are per acre. Trial initiated 6-21. Sequential applied 8-2.

78bc

94a

63d69cd

63d

Purple Nutsedge (Cyperus rotundus) Control

0

20

40

60

80

100

14 WAIT

# Sh

oots

/FT

²

Untreated

Monument .35 oz

Monument .59 oz

Monument .35 oz +Bueno 6 1.33ptManage 1.27 oz

Image 2.67 pt

Rates are per acre. Trial initiated 6-21. Sequential applied 8-2.

92a

16bc

5c

40b 38b 35b

Untreated

Monument .35 fb .35 oz

Monument .59 fb .59 oz

Manage 1.27 fb 1.27 oz

Image 2.67 fb 2.67 pt

False Green Kyllinga (Kyllinga gracillima) Control

0

20

40

60

80

100

6 WAIT

% C

ontr

ol

Monument .47 oz

Monument .47 fb .47 oz

Manage 1.33 oz

Manage 1.33 fb 1.33 oz

Image + MSMA .5 + 2 lb ai

85 a

97 a

82 a 84 a87 a

Rates are per acre. All trts included 0.25% v/v NIS. Trial initiated 5-7. Sequential applied 5-27.

False Green Kyllinga (Kyllinga gracillima) Control

0

20

40

60

80

100

16 WAIT

% C

ontr

ol

Monument .47 oz

Monument .47 fb .47 oz

Manage 1.33 oz

Manage 1.33 fb 1.33 oz

Image + MSMA .5 + 2 lb ai

99 a 99 a

64 b

99 a 99 a

Rates are per acre. All trts included 0.25% v/v NIS. Trial initiated 5-7. Sequentials were applied 5-27.

Yellow Nutsedge (Cyperus esculentus) Control

0

20

40

60

80

100

6 WAIT

% C

ontr

ol

Monument .47 oz

Monument .47 fb .47 oz

Manage 1.33 oz

Manage 1.33 fb 1.33 oz

Image + MSMA .5 + 2 lb ai

100 a 98 a93 a

63 bc

35 d

Rates are per acre. All trts included 0.25% v/v NIS. Trial initiated 5-13. Sequential applied 6-23.

Yellow Nutsedge (Cyperus esculentus) Control

0

20

40

60

80

100

6 WAIT

% C

ontr

ol

Flaz 1.5 fb 1.5 oz

Flaz 3 oz

Flaz 3 fb 3 oz

Sulfo 1.33 fb 1.33 oz

MSMA 2 fb 2 lb ai

80 ab

100 a98 a93 a

45 cd

Rates are per acre. All trts included 0.25% v/v NIS. Trial initiated 5-13. MSMA seq applied 5-26, flaz seq applied 6-3, sulfo seq applied 7-28.

Yellow Nutsedge (Cyperus esculentus) Control

0

20

40

60

80

100

16 WAIT

% C

ontr

ol

Monument .47 oz

Monument .47 fb .47 oz

Manage 1.33 oz

Manage 1.33 fb 1.33 oz

Image + MSMA .5 + 2 lb ai

61 abc

30 bcd

69 ab

56 abc

19 cd

Rates are per acre. All trts included 0.25% v/v NIS. Trial initiated 5-13. Sequential applied 6-23.

Yellow Nutsedge (Cyperus esculentus) Control

0

20

40

60

80

100

16 WAIT

% C

ontr

ol

Flaz 1.5 fb 1.5 oz

Flaz 3 oz

Flaz 3 fb 3 oz

Sulfo 1.33 fb 1.33 oz

MSMA 2 fb 2 lb ai

25 bcd20 cd

58 abc

81 a

39 a-d

Rates are per acre. All trts included 0.25% v/v NIS. Trial initiated 5-13. MSMA seq applied 5-26, flaz seq applied 6-3, sulfo seq applied 7-28.

Key Factors for Sedge Control

Make initial application when sedges are actively-growing (need good soil moisture)

Repeat the application MSMA – 7 to 10 days Basagran T/0 – 7 to 10 days Monument, Manage, Katana, Battalion, Image

– 4 to 8 weeks (when regrowth is noted)

Key Factors for Sedge Control

Be aware of rainfast periods Image - NA (water 1 to 7 d after) Monument – 3 hrs Manage – 3 to 8 hrs Basagran T/O – 4 hrs MSMA/DSMA – 24 hrs

Add adjuvant as per label.

Key Factors for Sedge Control

Map infestations Include MSMA in rotation plan, especially

for kyllinga Include Basagran T/O in rotation plan,

especially for yellow nutsedge

Key Factors for Sedge Control

Follow all approved cultural practices Eliminate drainage problems Don’t over-irrigate and create habitat

favored by sedges and kyllinga

Plan on a multi-year program Persistence will be required

Sedge control ratings for selected turfgrass herbicides. (From McCarty, Murphy and Yelverton)

HerbicideAnnual Sedge

Purple Nutsedge

YellowNutsedge

Annual Kyllinga

Green Kyllinga

Pennant G P G F-G P

Ronstar G P P F P

Basagran T/O G P G F-G F-G

Image G G P-F G G

Manage G G G G F-G

MSMA/DSMA G P-F F G G

Image + MSMA

G G-E G G G

Monument ?? G-E G G G-E

???QUESTIONS????

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