GRASS CONTROL IN RIGHTS-OF-WAY & NATURAL AREAS. Sarah Lancaster

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1 GRASS CONTROL IN RIGHTS-OF-WAY & NATURAL AREAS Sarah Lancaster

2 Outline -General management techniques -Identification -Management recommendations -Current research

3 Pest management programs -Identify the target -Evaluate population - Know action threshold -Select control method - Mechnical, biological, chemical, cultural -Monitor control

4 Torpedograss (Panicum repens) -Native to Africa and or Asia -Introduced into Florida in late 1800 s - wetland forage grass -Perennial, spreads through rhizomes -Roots on shore, extends into shallow water - Forms dense monoculture along shoreline of lakes and ponds

5 Torpedograss % of biomass is below ground

6 Torpedograss feet tall - Leaf sheath with or without hairs - Usually at the upper sheath margin - Ligule a short ciliate membrane - Leaf blades - Flat or folded inches long, 0.3 inches wide - Stiff - Upper usually hairy, near collar

7 Torpedograss -Inflorescence - Loose, open panicle inches long - branches ascending -Seed - Small, white - Variable viability

8 Para grass (Urichloa mutica) -Native to Africa -Introduced into Florida in late 1800 s - Wetland forage grass -Perennial, spreads through stolons and seeds -Prefers water fluctuations

9 Para grass -3 feet tall when upright - 5 feet long when creeping -Dense stiff hairs on sheath -Nodes swollen and hairy -Ligule a ciliate membrane -Leaf blades - Flat - 10 inches long; 0.5 in inches wide; - Small fine hairs near collar

10 Para grass -Inflorescence - Terminal raceme - 8 inches long ascending, alternate branches - Often purple-tinged -Seed - Reportedly very low seed production and viability

11 West Indian marsh grass (Hymenachne amplexicaulis) -Native to Caribbean -Introduction to Florida uncertain -Perennial, spreads through stolons and seeds -Prefers water fluctuations and high nutrients

12 West Indian marsh grass -3-8 feet tall -Leaf sheath glabrous - Some hairs on upper margins -Ligule membranous -Leaf - Flat - 14 inches long; 1.6 inches wide - Clasping at the stem - Long hairs on lower margin

13 West Indian marsh grass -Pithy stem

14 West Indian marsh grass -Inflorescence - Dense, terminal spike inches wide; 20 inches long -Seeds - Stick to animals, clothes - 98% germination

15 Limpograss (Hemarthria altissima) -Native to Africa -Introduced into Florida in Wetland forage grass -Perennial, spreads through stolons -Four cultivars released; similar attributes

16 Limpograss -3-6 feet tall -Leaf sheath usually glabrous, - Red coloration - Sometimes with fringe of hairs -Ligule a ciliate membrane -Leaf blade 2-6 inches long; 0.1 inch wide - Depends on cultivar

17 Limpograss -Inflorescence - Single spike or panicle of several spikes - 2 to 8 in. long -Seed - Few produced - Highly viable

18 Control of Perennial Grasses -Two products of choice: -Glyphosate - Terrestrial (Roundup, etc.) vs. Aquatic (Rodeo, etc.) - 4-7½ pints/acre - Retreatment necessary when plants partially submerged -Imazapyr - Terrestrial (Arsenal, etc.) vs. Aquatic (Habitat, etc.) pints/acre - Retreatment necessary depending on the species

19 Torpedograss -Glyphosate pints/acre - 2-3% solution - Only translocates in tissues above water - Retreatment necessary when a portion of the plant is below water -Imazapyr - 4 pints/acre to 1% solution - Translocates throughout plant even below water line - Retreatment likely with dense infestations

20 Para grass -Glyphosate - 6 pint/acre - Best if applied to lush growth - May require burning and treating new regrowth - Will have to retreat escapes -Imazapyr - 2 to 4 pint/acre - Higher rate for more established stands - Quicker recovery of native species in standing water

21 West Indian marsh grass -Glyphosate - 7 pint/acre -Imazapyr - 4 to 6 pint/acre - Native species quick to reestablish if water present at application -Water depth at application not an issue with either herbicide

22 Limpograss -Very sensitive to glyphosate - 6 pints/acre - Even to very old growth; new regrowth less sensitive -Imazapyr - 2 pints/acre -No information on water depth available

23 Selective herbicides -Control grasses only - 24c Label - Public good provision for off-patent products - 7 years patent protection -Several show potential - clethodim, sethoxydim, fenoxaprop, fluazifop, quizalofop, and nicosulfuron

24 Results 6 weeks after treatment glyphosate nontreated clethodim diclofop

25 Conclusions -Identify properly -Herbicide choices are glyphosate and/or imazapyr - Potential for selective herbicides -Scout for regrowth - Retreatment VERY likely

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