Spring Transition From Perennial Ryegrass To Bermudagrass. & Extension Specialist, NCSU

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1 Spring Transition From Perennial Ryegrass To Bermudagrass Fred Yelverton, PhD Professor & Extension Specialist, NCSU

2 TurfFiles Find this presentation and more online Sign-up for Turf ALERTS Learn about turfgrass pests: Weeds Insects Diseases Identify your turf or weed species using Decision Aids

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8 Sulfonylurea Herbicides Certainty Manor or Blade Revolver Monument Tranxit

9 Sulfonylurea Herbicides Interfere with acetolactate synthase (ALS Inhibitor) Readily absorbed by foliage and roots and translocated to meristematic region. Growth is inhibited in sensitive plants, followed by chlorosis and death of growing points. Usually takes about 10 to 21 days.

10 Characteristics of SU Herbicides Favorable environmental profile Low use rates Short-lived in soils (1/2 life 6-20 days) Warm-season grasses tolerant, cool-season grasses sensitive High water solubilities Weed sensitivity varies greatly

11 SU Herbicides in the Southwestern US Removal of perennial ryegrass Control of Poa annua Sedge control

12 Purple Nutsedge (Cyperus rotundus)

13 % Control Purple Nutsedge Control With Dismiss and Quicksilver Combinations cd a-d cd bcd ab a May 30 Application; Sep 14 Evaluation 2006: Plymouth Country Club Dismiss 4F 8 oz/a Dismiss 4F 12 oz/a Quicksilver 1.9EW 2 oz/a Dismiss 4F + Quicksilver 1.9EW oz/a Certainty 1.25 oz/a + NIS 0.25% Monument 0.56 oz/a + NIS 0.25% Check

14 Bermudagrass Bermudagrass has a high light requirement and does not grow well under low light or shady environments Increased light intensity and daylength increase rhizome, stolon, and leaf growth

15 Shade Tolerance of Various Turfgrasses Warm-Season Species St. Augustine zoysiagrass centipedegrass bermudagrass Shade Tolerance excellent good medium very poor

16 Bermudagrass Under low light (<60% full sunlight), bermudagrass develops narrow, elongated leaves, thin upright stems, elongated internodes, and weak rhizomes

17 Response of TifEagle to Shade % Shade Turf Quality a 3.85 b % Lateral Regrowth 69 a 34 b

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19 Bermudagrass The Problem Turf-type cool-season cultivars that perform well during the autumn overseeding establishment and winter playing season tend to persist well into the spring and early summer Canopy shading results in impaired bermudagrass greenup and possible stand loss

20 Bermudagrass spring transition (cont.) Minimizing spring transition problems Lower mowing height Increased nitrogen fertility Light vertical mowing Core aerification

21 Treatments Ammonium nitrate (4-25 & 6-13) -applied at 2 lbs / 1000ft 2 to wet turf foliage Core cultivation * Pronamide -applied at 1 lb ai/a Scalping * Vertical mowing * Vertical mowing / scalping * Nontreated * Treatments repeated every 2 weeks

22 Summary Verticutting, core cultivating and later ammonium nitrate application did not affect ryegrass transition.

23 Summary The perennial ryegrass in all treatments transitioned out at the same rate as the nontreated plots Thus environmental conditions ultimately dictated transition of overseeded perennial ryegrass to bermudagrass

24 Bermudagrass - Overseeding Trend to hold perennial ryegrass too long in the spring and overseed too early in the fall

25 How Much Growth Does Bermudagrass Need (w/o ryegrass competition)? About 100 days (Observation) Anything less will lead to a gradual decline of bermuda over time

26 Spring Transition- What Happens to Bermudagrass? Plant Competition: Light most plants compete for this Nutrients H 2 O CO 2

27 Spring Transition- What Happens to Bermudagrass? Bermudagrass is aggressive so is perennial ryegrass. In spring, competitive edge heavily favors perennial ryegrass. It s all about plant competition!

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31 Will There Be A Successful Spring Transition Without Herbicides? Depends on where you are: NC No Florida Yes South TX Yes Arizona No Palm Springs - Maybe

32 Spring Transition- What Happens to Bermudagrass? Long-term health of bermudagrass will hinge on successfully growing it back in prior to overseeding in the fall.

33 Summary It s all about light/shade

34 Spring Transition- What Happens to Bermudagrass? Bermudagrass that is not wellestablished should not be overseeded.

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38 What Is The Best Herbicide To Use? Kerb Manor or Blade Revolver Monument Tranxit Certainty

39 Rates (Based on Results) Kerb 1.0 lb ai/a Manor or Blade 0.5 oz/a + NIS Revolver 0.4 oz/m or 18 oz/a Monument 0.3 oz/a + NIS Tranxit 1.0 oz/a + NIS Certainty 1.33 oz/a + NIS

40 What Are The Issues With Herbicide Use? Costs: ranges from $40- $100/acre How fast do you want to kill it? Dead and dying ryegrass is not pretty Herbicides are mobile

41 What Is The Best Herbicide To Use? All five are effective in removing ryegrass (some also kill Poa annua) The speed that they remove ryegrass differs

42 Speed Of Kill with Transition Herbicides Revolver = Monument = Tranxit are faster than Manor which is faster than Kerb.

43 Speed Of Kill with Transition Herbicides Revolver, Monument, Tranxit days Manor or Blade days Kerb days

44 Sulfonylurea Herbicide Effects on Quick Trans Perennial Ryegrass Removal Revolver 17 oz Certainty 1.33 oz* Monument 0.27 oz* TranXit GTA 1 oz* Manor 0.5 oz* Flazasulfuron 1 oz* Jun Application date Apr 27, 2004

45 % Control Removal of Overseeded Perennial Ryegrass in Bermudagrass with Herbicides Monument 0.3 oz TranXit 1 oz Manor 0.5 oz Revolver 17.4 oz Kerb 1 lb ai 0 2 WAT 4 WAT

46 Movement (ft) Movement of SU Herbicides and Kerb WSP Following Irrigation on a 28o Slope Monument 0.33 oz/a* Monument 0.56 oz/a* Kerb WSP 3 lb/a* TranXit GTA 2 oz/a* Manor 0.5 oz/a* Revolver 17 oz/a Check 0 18-Mar

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48 Nontreated

49 trifloxysulfuron 29.5 g ai/ha

50 rimsulfuron 35 g ai/ha

51 foramsulfuron 29 g ai/ha

52 metsulfuron 21 g ai/ha

53 pronamide 1.7 kg ai/ha

54 trifloxysulfuron 29.5 g ai/ha

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57 To Reduce Tracking Risk Spray after traffic has left for the day Water lightly (5 minutes) to remove dew. Should be done next morning prior to traffic.

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