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JOHNSONGRASS
Johnsongrass
[Sorghum halepense (L.) Pers.]
DESCRIPTION
Johnsongrass
is not a common weed in turf situations. It is frequently found on roadsides,
but is also found in pastures and disturbed fields. It does not grow well in
frequent, close mowing situations. As an adult plant, johnsongrass is
characterized by its dense growth habit, with stems that can reach 6 ft in
height. The leaf blades are rough, and the prominent white raised midveins that
run the length of the leaf are distinctive. The seedhead is purple.
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Characteristic
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Description
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Seedhead / Flower
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panicle; seedhead is often purplish
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Vernation Type
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rolled
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Ligule Type
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membranous; fine hairs
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Growth Season / Life Cycle
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perennial weed
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Auricle Type
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absent
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Leaf Blade Tip Shape
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sharp-pointed
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Leaf Blade Width
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0.4 - 1.2 inches (10 to 30 mm) wide
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Stolon Presence
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absent
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Rhizome Presence
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present
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Collar Type
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continuous
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Sheath Margin
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open
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Sheath Type
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round to somewhat flattened
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johnsongrass
ligule, auricle
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johnsongrass
seedhead
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Note: Still not
sure this is the right weed? The Turf
& Weed Identification Decision Aid may help. Check the TurfFiles glossary for definitions
of unfamiliar terms.
CULTURAL
CONTROL
Perennial
grass weeds are not desirable as turfgrass species under any conditions.
Therefore, every effort should be made to prevent these weedy grasses from
becoming established in turf, as selective control measures are usually
difficult. Selection of adapted turfgrass species and cultivars and the use of
cultural practices are important in minimizing weedy grass encroachment and
competition. Management practices include (1) mowing at the recommended height
for the selected turfgrass and removing clippings when seedheads of grassy
weeds are present; (2) applying the proper amount of nitrogen at the correct
time according to the turfgrass present; and (3) using soil tests to determine
needed nutrients and lime.
CHEMICAL
CONTROL
Johnsongrass can be controlled
postemergence with fluazifop (Fusilade II), sethoxydim (Vantage), clethodim
(Envoy), and imazapic (Plateau). Nonselective control with glyphosate
(Roundup) may be an option but turf establishment will be needed after application.
Note:
Recommendations of specific chemicals are based upon information on the
manufacturer's label and performance in a limited number of trials. Because
environmental conditions and methods of application may vary widely,
performance of the chemical will not always conform to the safety and pest
control standards indicated by experimental data. The order in which brand
names are given is not an indication of a recommendation or criticism.
Recommendations for the use of
agricultural chemicals are included in this publication as a convenience to the
reader. The use of brand names and any mention or listing of commercial
products or services does not imply endorsement by North Carolina State
University or discrimination against similar products or services not
mentioned. Other brand names may be labeled for use on turfgrasses. Individuals
who use agricultural chemicals are responsible for ensuring that the intended
use complies with current regulations and conforms to the product label. Be
sure to obtain current information about usage regulations and examine a
current product label before applying any chemical. For assistance, contact
your county's Cooperative Extension agent.
© North Carolina State University. This information sheet was prepared
by Fred Yelverton, Bridget R. Lassiter, Gail G. Wilkerson, Leon Warren, Travis Gannon, Jenifer J. Reynolds, and Gregory S. Buol. Department of Crop
Science, College of Agriculture & Life Sciences, North Carolina State
University. Prepared July 15, 2008. Available on-line at
www.turffiles.ncsu.edu. This publication was made possible through a grant
provided by the Center for Turfgrass Environmental Research & Education
(CENTERE) whose purpose is to support worthwhile projects that will benefit
both the private sector and the public, and protect the environment.
KEYWORDS FOUND IN THIS ARTICLE:
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