Sedge Biology and Control in Warm-Season Turf Tim R. Murphy The 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 finetextured 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 100 99a Monument .35 oz 91b % Control 85c 80 74d 60 74d Monument .59 oz Monument .35 oz + Bueno 6 1.33pt 40 Manage 1.27 oz 20 Image 2.67 pt 0 6 WAIT Rates are per acre. Trial initiated 6-21. Sequential applied 8-2. Purple Nutsedge (Cyperus rotundus) Control % Control 100 80 Monument .35 oz 94a 78bc Monument .59 oz 69cd 63d 60 63d Monument .35 oz + Bueno 6 1.33pt 40 Manage 1.27 oz 20 Image 2.67 pt 0 14 WAIT Rates are per acre. Trial initiated 6-21. Sequential applied 8-2. Purple Nutsedge (Cyperus rotundus) Control # Shoots/FT² 100 Untreated 92a 80 Monument .35 oz 60 Monument .59 oz 40b 38b 40 20 16bc 35b Monument .35 oz + Bueno 6 1.33pt Manage 1.27 oz 5c Image 2.67 pt 0 14 WAIT Rates are per acre. Trial initiated 6-21. Sequential applied 8-2. 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 100 97 a % Control 85 a 80 82 a 84 a 87 a Monument .47 oz Monument .47 fb .47 oz 60 Manage 1.33 oz 40 Manage 1.33 fb 1.33 oz 20 Image + MSMA .5 + 2 lb ai 0 6 WAIT 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 100 99 a 99 a 99 a 99 a % Control Monument .47 oz 80 Monument .47 fb .47 oz 64 b 60 Manage 1.33 oz 40 Manage 1.33 fb 1.33 oz 20 Image + MSMA .5 + 2 lb ai 0 16 WAIT 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 100 100 a 98 a 93 a % Control Monument .47 oz 80 Monument .47 fb .47 oz 63 bc 60 Manage 1.33 oz 40 35 d Manage 1.33 fb 1.33 oz 20 Image + MSMA .5 + 2 lb ai 0 6 WAIT 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 100 100 a 98 a 93 a % Control Flaz 1.5 fb 1.5 oz 80 80 ab Flaz 3 oz 60 45 cd 40 Flaz 3 fb 3 oz Sulfo 1.33 fb 1.33 oz 20 MSMA 2 fb 2 lb ai 0 6 WAIT 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 100 % Control Monument .47 oz 80 69 ab 60 Monument .47 fb .47 oz 61 abc 56 abc Manage 1.33 oz 40 30 bcd Manage 1.33 fb 1.33 oz 19 cd 20 Image + MSMA .5 + 2 lb ai 0 16 WAIT 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 % Control 100 Flaz 1.5 fb 1.5 oz 81 a 80 Flaz 3 oz 60 58 abc Flaz 3 fb 3 oz 39 a-d 40 25 bcd 20 Sulfo 1.33 fb 1.33 oz 20 cd MSMA 2 fb 2 lb ai 0 16 WAIT 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) Annual Sedge G Purple Nutsedge 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 Herbicide Pennant Yellow Annual Green Nutsedge Kyllinga Kyllinga G F-G P www.georgiaturf.com ???QUESTIONS????