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Exotic Grasses in Our Forests. Art Gover Penn State PENNDOT Roadside Research Project Department of Horticulture. Resources. http://rvm.cas.psu.edu annual research reports training Powerpoints publications factsheets
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Exotic Grasses in Our Forests Art Gover Penn State PENNDOT Roadside Research Project Department of Horticulture
Resources • http://rvm.cas.psu.edu • annual research reports • training Powerpoints • publications • factsheets • applicator training materialsUse and Characteristics of Herbicides for Non-crop Weed Control - 42 pages, 132 K
Weed Management Basics • Bigger Picture: • Symptoms vs Cause • Broad Based Approach • Integrated Pest Management • Prevention & cure
Weed Management Basics • Strategic Plan • Prioritize objectives • Optimize finite resources • Ongoing evaluation of results and objectives
Japanese stiltgrass(Microstegium vimineum) • Annual grass • Shade tolerant • Germination begins mid-March/mid-April • Seedhead late-August/late-September
Stiltgrass Management • Prevent seed set • Consider seedbank as perennial • Once present, control is multi-year (ongoing) • Think '5 Year Plan'
Prevention • Sanitation - don't move seed/stems to uninfested areas • Establish alternate groundcover (where light permits) • Roadsides • Heavily used trails, trailheads
Controlling Stiltgrass • Mechanical • Mow/pull late summer (before seed set) • Mow low • String-trimming on 8/6/02 in Phila. Provided 93% control
Stiltgrass Control • Herbicides • Preventive (preemergence) • Curative (postemergence) • Labeling • Herbicide use is governed by SITE, not target species • Stiltgrass does not have to be listed on the label to legally use
Choosing an Herbicide • Stiltgrass growth stage • Site • Desirable species • Equipment
Herbicide Categories Preemergence - applied to soil, prevents establishment from seed Non-selective, contact - 'burndown' Non-selective, systemic - injures all vegetation, moves through plant Selective (graminicides) - injure only grasses
Preemergence • Used to control annual weeds in turf and ornamental beds • Must be applied before germination • Will not control emerged stiltgrass • Will not injure established plants • Similar to Preen
Preemergence • pendimethalin - Pendulum • oryzalin - Oryzalin T/O • prodiamine - Endurance • trifluralin - Treflan • oxyfluorfen - Goal 2XL
Non-selective, Contact • Only affects emerged plants • Affects contacted plant parts • Rapid symptoms - 2 to 5 days • Perennials will regrow • Most effective on small plants
Non-selective, Contact • glufosinate - Finale, Derringer • diquat - Reward
Non-selective, systemic • Plants must be emerged • Translocates throughout plant • All contacted plants affected • Low rates (16 to 32 oz/ac) kill stiltgrass, leave perennials • No soil activity
Non-selective, systemic • glyphosate • available in terrestrial and aquatic labels
Selective (Graminicides) • Plants must be emerged • Affect only grasses - not sedges, rushes, dicots • Smaller, annual grasses most sensitive
Selective (Graminicides) • quizalofop-P - Assure II • fluazifop-P - Fusilade II • sethoxydim - Vantage • clethodim - Envoy • fenoxaprop-P - Acclaim Extra
Plateau • Low use rates, 2 to 8 oz/ac • Very effective preemergence, fair-to-good postemergence • Journey is premix of Plateau plus glyphosate (8 oz Journey = 3 oz Plateau + 4 oz RoundUp)
Systemic, Residual • PRE and POST activity • Selectivity determined by rate, timing, and application
Systemic, Residual • sulfometuron - Oust XP • 0.5 to 1 oz/ac • imazapyr - Arsenal • ? - 8 oz/ac • imazapic - Plateau, Journey • 4 oz/ac Plateau • 8 - 12 oz/ac Journey
Stiltgrass - annual grass vegetative growth germination seed ripening
Stiltgrass - annual grass vegetative growth germination seed ripening PRE - pendimethalin, Endurance, oryzalin, trifluralin PRE/EARLY POST - Goal 2XL PRE/POST - Plateau, Journey, Oust, Arsenal POST - glyphosate, Finale, Assure II Mowing
Johnsongrass(Sorghum halepense) • perennial, C4 (warm season) • introduced 19th century, forage • stout rhizomes • Noxious weed in PA, MD, OH, WV • full sun
Virginia Tech Weed Identification Guide Johnsongrass rhizomes
Nonnative Invasive Plants of Southern Forests • Grasses • giant reed (Arundo donax) • tall fescue (Festuca arundinacea) • Cogongrass (Imperata cylindrica) • Nepalese browntop [stiltgrass] (Microstegium vimineum) • Chinese silvergrass (Miscanthus sinensis) • bamboos (Phyllostachys, Bambusa)
Johnsongrass Control • June, prior to seed ripening • Herbicides • imazapyr • sulfometuron • glyphosate • imazapic • imazapic + glyphosate
Johnsongrass - perennial grass flowering rhizome production rhizome initiation seed germ
Johnsongrass - perennial grass flowering rhizome production rhizome initiation seed germ Early POST: graminicides Pre seed-set: glyphosate, Oust, Arsenal