Herbicide Selection: What can I use, and where can I use it?

Transcription

1 Herbicide Selection: What can I use, and where can I use it? Art Gover Wildland Weed Management Crop and Soil Science College of Agricultural Sciences

2 Acknowledgement PA DCNR, Bureau of State Parks, Resources Management Section ISM planning & implementation, operational training, classroom training, control research, Weed Warrior program

3 P u b lic a tio n s R o a d s id e V e g e ta tio n M a n a g e m e n t F a c ts h e e ts F a c t s h e e t 1 : Implementing Integrated Veg. Management on Pennsylvania's Roadsides F a c t s h e e t 2 : Improving the Success of Roadside Tree and Shrub Plantings F a c t s h e e t 3 : Managing Tree-of-Heaven (A i l a n t h u s a l t i s s i m a ) on Roadsides F a c t s h e e t 4 : Tips for Managing Problem Weeds in Forest and Wildland Settings F a c t s h e e t 5 : Managing Japanese and Giant Knotweed on Roadsides F a c t s h e e t 5 a : Managing Japanese and Giant Knotweed on Roadsides F a c t s h e e t 6 : Tree-of-heaven (A i l a n t h u s a l t i s s i m a )- or, The Tree that Ate Perry County F a c t s h e e t 7 : Selecting Plant Materials for the Next Generation of Roadside Groundcover F a c t s h e e t 8 : Suggested Herbicide Mixtures for Roadside Vegetation Management C R E P W e e d M a n a g e m e n t F a c ts h e e ts F a c ts h e e t F a c ts h e e t F a c ts h e e t F a c ts h e e t F a c ts h e e t 1 : Managing Canada Thistle 2 : Managing Multiflora Rose 3 : Managing Purple Loosestrife 4 : Managing Japanese Knotweed 5 : Weed Management in Riparian Forest Buffers S ta te P a r k s In v a s iv e S p e c ie s M a n a g e m e n t Q u ic k s h e e ts Q Q Q Q Q Q Q u ic k s h e e t u ic k s h e e t u ic k s h e e t u ic k s h e e t u ic k s h e e t u ic k s h e e t u ic k s h e e t 1 : Japanese knotweed (Polygonum cuspidatum) 2 : Common reed (Phragmites australis) 3 : Exotic shrubs 4 : Japanese stiltgrass (Microstegium vimineum) 5 : Tree-of-heaven (Ailanthus altissima) 6 : Purple loosestrife (Lythrum salicaria) 7 : Mile-a-minute (Polygonum perfoliatum) H e r b ic id e A p p lic a t o r T r a in in g M M M M M o d u le o d u le o d u le o d u le o d u le 1 : Integrated Vegetation Management 2 : PENNDOT Herbicide Program Overview 3 : Weed Biology 4 : Noxious and Troublesome Roadside Weeds 1 1 : Herbicide Formulations and Adjuvants O th e r P u b lic a tio n s

4 Q u ic k S h e e t V e g e ta tio n M a n a g e m e n t Department of Horticulture College of Agricultural Sciences In v a s iv e P la n t S p e c ie s M a n a g e m e n t 4 J a p a n e s e s tiltg r a s s (M ic r o s te g iu m v im in e u m ) D e s c r ip tio n Refer to the DCNR Invasive Exotic Plant Tutorial stiltgrass page ( ial/japanese_stiltgrass.htm). Herbaceous, annual, warm-season grass. Tolerant of full sun to heavy shade. Has a sprawling growth habit, with a canopy height between 12 and 24 inches. Seedheads emerge late-august to earlyseptember. Infestations commonly start along road or trail edges, then spread outward. M anagem ent Keys As a plant, stiltgrass is not hard to suppress. However, treatment often begins after stiltgrass has spread extensively and established a persistent seedbank, making control difficult. T a r g e t th e S e e d b a n k To eliminate stiltgrass, you have to prevent seed production, and exhaust the seed lying in wait in the soil. You should plan on at least a five-year process. P r e v e n tio n is E a s ie r If stiltgrass is just getting onto your site, determine where it s coming from. Shale and gravel for roadwork are common sources. Roadwork where stiltgrass is already established spreads it even further. M e c h a n ic a l C o n tr o l Small infestations of stiltgrass are readily pulled. A trimmer can be effective later in the season (Figure 1), if you cut the stiltgrass off at ground level. A lawnmower cuts too high and will not work, as stiltgrass is a common weed in turf. E a r ly C o n tr o l It is common to first observe stiltgrass along roads or trails. The infestation tends spread along the road or trail, then spread away into the understory. It is relatively easy to treat stiltgrass while it occurs as a narrow, linear infestation. R e c o m m e n d e d H e r b ic id e s Stiltgrass is susceptible to a number of herbicides, allowing you to tailor a program that fits your schedule germination JA N and the plant community you are trying to preserve. Preemergence herbicides that are effective against stiltgrass include p e n d i m e t h a l i n ( Pendulum ), i m a z a p i c ( Panoramic ), and s u l f o m e t u r o n ( Oust XP ). I m a z a p i c and s u l f o m e t u r o n can also be applied postemergence for effective control of stiltgrass. P e n d i m e t h a l i n will have the least effect on non-target species of these three materials, but it is also the least flexible to use. P e n d i m e t h a l i n must already be in the soil where the seed is germinating it has to be absorbed by the emerging root tip to be effective. P e n d i m e t h a l i n has no effect on already established vegetation. I m a z a p i c and s u l f o m e t u r o n provide more flexibility in terms of application timing, but they will cause more injury to non-target herbaceous plants than p e n d im e t h a lin. Three postemergence herbicides that are effective against stiltgrass include g l y p h o s a t e ( Aquaneat ), g l u f o s i n a t e ( Finale ), and q u i z a l o f o p ( Assure II ). G l y p h o s a t e is non-selective and systemic, and will injure all treated vegetation. Gl u f o s i n a t e is also nonselective, but it is a contact herbicide, so the damage to treated non-target plants will be limited to where the spray contacted the plant. The herbicide q u i z a l o f o p only injures grasses. Stiltgrass is affected by q u i z a l o f o p at low rates, so you can control stiltgrass but leave native woodland grasses such as whitegrass (L e e r s i a v i r g i n i c a ), nimblewill (M u h l e n b e r g i a s c h r e b e r i ), and autumn bentgrass (A g r o s t i s p e r e n n a n s ) largely intact. A lte rn a te G ro u n d c o v e r If conditions permit, you should try to establish a groundcover to compete with the stiltgrass. If there already is groundcover, try to encourage its growth. Turf that is mowed too short and too often is more prone to stiltgrass infestation than a properly maintained turf. B e P e rs is te n t Stiltgrass can only be effectively controlled with repeated, annual effort. If you back off one season, the seedbank will be replenished, and your progress to date will be set back. T h is w o r k w a s s p o n s o r e d b y th e P e n n s y lv a n ia D e p a r tm e n t o f C o n s e r v a tio n a n d N a tu r a l R e s o u r c e s, B u r e a u o f S ta te P a r k s ( P A D C B y A r t G o v e r, J o n J o h n s o n, K ir s t y L lo y d, a n d J im S e l lm e r, T h e c o n t e n t s o f t h is w o r k r e f le c t t h e v i e w s o f t h e a u t h o r s w h o a r e th e fa c ts a n d th e a c c u r a c y o f t h e d a ta p r e s e n t e d h e r e in. T h e c o n te n ts d o n o t n e c e s s a r ily r e fle c t th e o f fic ia l v ie w s o r p o lic ie s o f t h e P e n n s y lv a n ia S ta te U n iv e r s ity a t th e tim e o f p u b lic a tio n. W h e r e t r a d e n a m e s a p p e a r, n o d is c r im in a t io n is in t e n d e d, a n d n o e n d o r s e m e n t b y t h e P e n n S t a t e C o lle g e o f A g r i c u lt u r a l S c ie n c e s F ig u r e 1. T h e o b j e c t iv e o f s t ilt g r a s s m a n a g e m e n t is t o p r e v e n t s e e d s e t. S t ilt g r a s s is e f f e c t iv e ly c o n t r o lle d w it h p r e e m e r g e n c e o r p o s te m e r g e n c e h e r b ic id e a p p lic a tio n s, a n d s m a ll in fe s ta tio n s c a n b e h a n d - p u lle d o r c u t a t g r o u n d le v e l. N R ). r e s p o n s ib le fo r PA D C N R or The is im p lie d. FEB MAR APR flowering and seed ripening MAY JU N JU L AUG SEP OCT NOV DEC Pendulum herbicide Oust, Panoramic herbicides Aquaneat, Finale, Assure II herbicides pulling, cutting T a b le 1. P r e s c r ip tio n s fo r e lim in a t io n o f J a p a n e s e s tiltg r a s s f o c u s o n p r e v e n tin g s e e d s e t. S t iltg r a s s is s u s c e p t ib le to a n u m b e r o f h e r b ic id e s s u it a b le fo r u s e in p a r k s. S m a ll in fe s ta t io n s c a n b e p u lle d o r c u t a t g r o u n d le v e l, w h ic h fa c ilit a te s th e u s e o f v o lu n t e e r s. t im in g tr e a tm e n t early- to mid Pendulum Aquacap March Panoramic early-march or through May Oust XP mid-may through August July through August Aquaneat or Finale or Assure II pulling or cutting p ro d u c t ra te c o m m e n ts 4.2 qts/acre Preemergence applications of Pendulum (p e n d i m e t h a l i n ) prevent stiltgrass establishment, and have little effect on plants that are already present. It is critical that p e n d i m e t h a l i n be applied two to three weeks prior to germination to allow rainfall to move it into the soil profile. P e n d i m e t h a l i n is also effective against mile-a-minute. 8 to 12 oz/acre or 1 to 3 oz/acre Panoramic (i m a z a p i c ) and Oust XP (s u l f o m e t u r o n ) have pre- and postemergence activity against stiltgrass. Preemergence applications will cause less damage to non-target species than postemergence applications. There comes a point in the season when you are better off using an herbicide that is not soil active (see below), to reduce the impact on non-target plants. 24 oz/acre or 4 qts/acre or 4 oz/acre Aquaneat (g l y p h o s a t e ) and Finale (g l u f o s i n a t e ) are non-selective herbicides with no soil activity. Finale only injures the parts of the plant it contacts, while Aquaneat is systemic, and will kill the entire plant. Assure II (q u i z a l o f o p ) only affects grasses, but the rate used for stiltgrass is low enough that desirable grasses such as whitegrass (L e e r s i a v i r g i n i c a ), and nimblewill (M u h l e n e r g i a s c h r e b e r i ) are only temporarily affected. n/a Small infestations of stiltgrass can be mechanically controlled. If you re cutting, use a trimmer that will cut the stiltgrass at the ground line to prevent resprouting from the lower nodes of the stem. The key to this treatment is to wait so that more stiltgrass will not germinate, but finish before the seedheads emerge. T h is p u b lic a t io n is a v a ila b le in a lt e r n a tiv e m e d ia o n r e q u e s t. T h e P e n n s y lv a n ia S ta te U n iv e r s ity is c o m m itte d to th e p o lic y th a t a ll p e r s o n s s h a ll h a v e e q u a l a c c e s s to p r o g r a m s, fa c ilitie s, a d m is s io n, a n d e m p lo y m e n t w ith o u t r e g a r d to p e r s o n a l c h a r a c t e r is t ic s n o t r e la t e d t o a b ilit y, p e r f o r m a n c e, o r q u a lif ic a t io n s a s d e t e r m in e d b y U n iv e r s it y p o lic y o r b y s t a t e o r f e d e r a l a u t h o r it ie s. I t is t h e p o lic y o f t h e U n iv e r s i t y t o m a in t a in a n a c a d e m ic a n d w o r k e n v i r o n m e n t f r e e o f d is c r im in a t io n, in c lu d in g h a r a s s m e n t. T h e P e n n s y lv a n ia S t a t e U n iv e r s it y p r o h ib it s d is c r im in a t io n a n d h a r a s s m e n t a g a in s t a n y p e r s o n b e c a u s e o f a g e, a n c e s t r y, c o lo r, d is a b ilit y o r h a n d i c a p, n a t io n a l o r ig in, r a c e, r e lig i o u s c r e e d, s e x, s e x u a l o r ie n t a t io n, g e n d e r id e n t it y, o r v e t e r a n s t a t u s. D is c r i m in a t io n o r h a r a s s m e n t a g a i n s t f a c u lt y, s t a f f, o r s t u d e n t s w ill n o t b e t o le r a t e d a t T h e P e n n s y lv a n ia S t a t e U n iv e r s it y. D ir e c t a ll in q u ir ie s r e g a r d in g t h e n o n d i s c r im in a t io n p o lic y t o t h e A ff ir m a t iv e A c t io n D i r e c t o r, T h e P e n n s y lv a n ia S t a t e U n iv e r s it y, B o u c k e B u il d in g, U n iv e r s it y P a r k, P A ; T e l / V, /T T Y.

5 Overview Basic herbicides Niche herbicides Product considerations formulation inert ingredients

6 Management - IPM Clear objective Prioritization Use all tools at your disposal cultural mechanical biological chemical

7

8

9

10

11

12

13 Competitive Plant Communities

14 Biocontrol Mile-a-minute weevils

15 Damage from weevils on mile-a-minute plants

16

17

18 Herbicide Application Methods Foliar applications Woody stem - cut surface Woody stem - basal bark Soil applications-preemergence

19 Foliar low volume

20 Foliar high volume

21 stump treatment

22 hack and squirt

23 basal bark

24 preemergence

25 Basic Herbicides Glyphosate Triclopyr Pendimethalin 2,4-D

26 Glyphosate Products Rodeo, Aquamaster, Aquaneat, Glyphomate 41 Non-selective Systemic No soil activity Aquatic labeling Low risk, familiarity

27 Glyphosate Product Toxicity Issues 2005 Study from Pitt suggested Roundup was toxic to amphibians Lack of clarity What is Roundup? Toxic constituent is tallowamine surfacant polyoxyethyleneamine (POEA) used in original Roundup formulations

28 Toxicity of Inerts original Roundup surfactant was polyoxyethyleneamine (POEA) Danger label when sold by itself non-reversible eye injury

29 Inert Ingredients Influence Signal Word glyphosate lb ae/gal POEA Signal Word Roundup Pro 3 none Caution Roundup Original 3 8% Warning ClearOut % Danger Product

30 POEA Toxicity Toxicity of Roundup ingredients to tadpoles of Xenopus laevis Treatment LC50 (96 hr) Roundup (glyph + POEA) 12.4 POEA Rodeo (glyph-ipa) 6.8 9,729 (=2% v/v) Perkins, P.J., H.J. Boermans, and G.R. Stephenson Toxicity of glyphosate and triclopyr using the frog embryo teratogenesis assay- Xenopus. Environmental Toxicology and Chemistry. 19:

31 Triclopyr Products Garlon 3A water soluble Pathfinder II RTU stem treatment Selective injures broadleaves Little soil activity Aquatic labeling (3A)

32 Pendimethalin Pendulum AquaCap Only injures germinants Little effect on established plants Significant soil activity Terrestrial applications only

33 No treatment 90 DAT

34 Pendulum applied PRE

35 Oust XP applied PRE

36 2,4-D Many formulations, products Use dimethylamine salt (DMA) Selective (broadleaves) Little soil activity Aquatic labeling

37 2,4-D? Combine with triclopyr broaden spectrum aquatic labeling low soil acivity

38 Herbicides Herbicide Cut Foliar surface Basal bark PRE Glyphosate Yes Yes No No Garlon 3A Yes Yes No No Pathfinder II No Yes Yes No Pendulum No No No Yes 2,4-D Yes Yes No No

39 Using the Basics Exotic shrubs Japanese knotweed (creeping perennial) Tree-of-heaven (suckering tree) Mile-a-minute Stiltgrass

40 Exotic Shrubs JAN FEB MAR APR MAY JUN JUL AUG SEP foliar basal bark, cut surface OCT NOV DEC

41 Exotic honeysuckles

42 Exotic honeysuckles

43 Autumn olive

44 Multiflora rose

45 Glossy buckthorn

46 Glossy buckthorn

47 privets

48 burning bush (Eonymus)

49 Mixes for Shrubs Glyphosate + triclopyr Triclopyr + 2,4-D*

50 Percent Reduction applied 9/09, rated 11 MAT treatment lb ae/ac untreated* gly:tri 3: gly:tri 0: gly:tri 1.5: gly:tri 2: gly:tri 2.4: P-LSD (0.05) autumn olive honeysuckle

51 Percent Reduction treatment lb ae/ac untreated* autumn olive honeysuckle 0 0 triclopyr triclopyr + 2,4-D P-LSD (0.05)

52 Current Mix active lb ae/ac product product/ac glyphosate 3.0 Aquaneat 3 qt triclopyr 1.5 Garlon 3A 2 qt surfactant % v/v

53 tree-of-heaven Ailanthus altissima (root suckering woody)

54

55 Ailanthus - suckering tree seed set leaf-out flower fall color vegetative growth Apr May Jun Jul Aug Sep Oct foliar: glyphosate, triclopyr, both hack/squirt: glyphosate, Garlon 3A basal bark: Pathfinder II

56 Japanese knotweed Polygonum cuspidatum

57 Japanese Knotweed - perennial forb vegetative growth seed ripening Feb Mar Apr May Jun Jul Aug Sep Oct Chemical mowing-herbicide follow-up Mowing for herbicide follow-up POST - glyphosate POST following years

58

59 mile-a-minute Polygonum perfoliatum

60 Mile-a-minute - annual forb germination Feb Mar Apr May flowering, seed ripening Jun Jul Aug PRE pendimethalin POST- glyphosate, triclopyr Pulling* Sep Oct

61 Japanese stiltgrass (Microstegium vimineum)

62 Stiltgrass - annual grass vegetative growth germination Feb Mar Apr May seed ripening Jun Jul Aug Sep PRE pendimethalin POST glyphosate (low rate) Oct

63 Specialty Herbicides Imazapic (Plateau) Aminopyralid Clopyralid Aminocyclopyrachlor POST graminicides prodiamine

64 Imazapic Plateau, others, Journey Weed control in warm-season grasses Tank-mix with pendimethalin to extend application window low rate (1 oz product/ac) maintain selectivity

65 Aminopyralid Milestone VM OpenSight (with metsulfuron) Milestone VM Plus (with triclopyr) Selective (broadleaves) Canada thistle, mugwort (?), kudzu shrubs (?)

66 Applied Oct 19, 2005 Milestone VM - 7 oz/ac Overdrive - 8 oz/ac

67 Drawbacks-aminopyralid Water s edge, not aquatic soil activity

68 Clopyralid Transline Selective (broadleaves) Canada thistle, mugwort (?) Kudzu labeled around some tree species

69 Drawbacks-Clopyralid More site restrictions than aminopyralid Soil activity

70 Aminocyclopyrachlor (ACP) Streamline (with metsulfuron) Selective (broadleaves) Canada thistle woody species

71 Selective Shrub Mixes* Products Rate/Acre Garlon 3A + 2,4-D 4 qt 2 qt Garlon 3A + OpenSight 4 qt 3.3 oz Garlon 3A + Streamline 4 qt 4.75 oz

72 POST Graminicides quizalofop-p (Assure II) sethoxydim (Segment) fluazifop-p (Fusilade II) clethodim (Envoy Plus) Selective (grasses only)

73 Stiltgrass - annual grass vegetative growth germination Feb Mar Apr May seed ripening Jun Jul Aug Sep PRE pendimethalin POST glyphosate (low rate) graminicide (low rate) Oct

74

75 Drawbacks - graminicides Terrestrial only EC formulations

76 Prodiamine Proclipse, Barricade similar to pendimethalin germinants only little effect on established plants not prohibited by FSC

77 Drawbacks - Prodiamine Fewer sites than pendimethalin No CRP use

78 More Specialty Herbicides imazapyr (Habitat) metsulfuron (Escort XP) sulfometuron (Oust XP)

79 Imazapyr Habitat, Arsenal, Chopper, Stalker non-selective at higher rates soil activity terrestrial, aquatic (Habitat) phragmites, cattails

80

81 Metsulfuron Escort XP Selective-ish (broadleaves) Soil Activity Used primarily in tank mixes, premixes multiflora rose, ailanthus

82 Drawbacks - Metsulfuron Higher rates injure grasses Significant soil activity

83 Sulfometuron Oust XP PRE, foliar Forestry uses, conifer and limited hardwood

84 Oust XP applied PRE

85 Drawbacks-Sulfometuron Not a selective PRE Injures established vegetation, even applied PRE

86 Take Home A few herbicides will do most of the work Limit non-target risk Reduce inventory Reduce prescriptions

87 College of Agricultural Sciences Art Gover Penn State Wildland Weed Management Department of Crop and Soil Sciences (814)