ManageMent guide foR italian RyegRass - Monsanto
ManageMent guide foR italian RyegRass - Monsanto
ManageMent guide foR italian RyegRass - Monsanto
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<strong>italian</strong><br />
Ryegrass<br />
<strong>ManageMent</strong> <strong>guide</strong> <strong>foR</strong> <strong>italian</strong> <strong>RyegRass</strong><br />
this document is intended to provide<br />
information about this weed and <strong>guide</strong>lines<br />
for control. as a tough-to-control weed,<br />
knowledge about the biology and weed<br />
control programs will help in management.<br />
<strong>italian</strong> Ryegrass Biology<br />
u Italian ryegrass is found in roadsides, ditches<br />
and increasingly in fields. The plant is<br />
palatable to livestock and produces forage.<br />
However, Italian ryegrass has encroached<br />
into fields, competing with wheat for<br />
moisture and nutrients. Weed contamination<br />
of harvested grain can cause considerable<br />
price dockage. 1<br />
u Italian ryegrass is distributed throughout<br />
the U.S. It is widely adaptable to many<br />
soils, but thrives on dark, rich soils in mild<br />
climates. It does not withstand hot, dry<br />
weather or severe winters, but can stand<br />
fairly wet soils with good drainage. 4<br />
u Italian ryegrass is an upright annual that<br />
acts like a biennial or short-lived perennial.<br />
It reproduces by seed and grows in winter<br />
and early spring. Hairless seedling leaves<br />
are shiny. The mature plant grows 1 to 4<br />
feet tall. Terminal spikes are flat and<br />
alternate along the stem. Long bristles<br />
are on the spikelets. At least 10 florets<br />
per spikelet differentiate Italian from<br />
perennial ryegrass. 1<br />
u Seeds are relatively flat and very light, so<br />
they are easily transported by wind. They<br />
are held reasonably tight to the flower<br />
stem, and need some form of force to drop<br />
them to the ground as individual seeds or as<br />
part of the flower stem. 2<br />
1 http://www.ipm.ucdavis.edu/PMG/WEEDS/<strong>italian</strong>_ryegrass.html<br />
2 http://weedman.horsham.net.au/weeds/lolium_rigidum/lolium_rigidum.htm<br />
3 Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet.<br />
May 15, 2008. Available www.weedscience.com.<br />
4 http://plants.usda.gov/factsheet/pdf/fs_lopem2.pdf<br />
5 http://www.ca.uky.edu/agc/news/2006/aug/ryegrass.htm<br />
Weed environment<br />
www.weedresistancemanagement.com<br />
u Annual ryegrass is a prolific seed producer.<br />
Italian ryegrass and wheat have similar<br />
maturity, so without good control measures<br />
the grass chokes out wheat in the field. At<br />
harvest, seed is further dispersed across the<br />
field by combines. 5<br />
u As much as 85 percent yield loss has<br />
occurred as a result of ryegrass competition<br />
in wheat. One plant per square foot can<br />
reduce yields by four percent. 5<br />
u Widespread distribution of Italian ryegrass<br />
and rapid, extensive development of<br />
resistance may also be partly due to large<br />
genetic variability in the species. 2<br />
u When seed bank numbers are high and the<br />
ryegrass becomes established early in the<br />
growing season, problems occur. Ryegrass<br />
produces large numbers of tillers and even<br />
a low density of plants can return a mass of<br />
seed to the seed bank. 2<br />
u Glyphosate-resistant Italian Ryegrass<br />
populations have been confirmed in<br />
Mississippi and Oregon.
treatment Recommendations 1<br />
Scout fields and control weeds throughout the season. Proper application timing protects yields, ensures correct use rate for<br />
weed size and considers the impact of environmental conditions on performance.<br />
Roundup Ready ® Corn 2*<br />
u Start clean with a burndown herbicide or tillage.<br />
Early-season weed control is crucial in corn to<br />
maximize yield potential.<br />
u Apply a preemergence residual herbicide such as<br />
Harness ® Xtra or Degree Xtra ® , or other residual<br />
herbicides at the recommended rate.<br />
u Or apply a preemergence residual herbicide at the<br />
recommended rate tank mixed with Roundup<br />
WeatherMAX ® at a minimum of 22 oz/A in-crop.<br />
u Follow either program with a postemergence in-crop<br />
application of Roundup WeatherMAX at a minimum rate<br />
of 22 oz/A.<br />
u Tank mix other herbicides such as Accent ® , Equip ® or<br />
Option ® to control emerged Italian ryegrass if you suspect<br />
the ryegrass is resistant to glyphosate.<br />
*Includes corn with Roundup Ready 2 Technology<br />
Roundup Ready soybeans<br />
u Start clean with a burndown herbicide or tillage. Tank<br />
mixing with 2,4-D will help provide more effective<br />
burndown control.<br />
u An application of a residual herbicide will provide control<br />
of a number of grass and broadleaf weeds in early season,<br />
reducing the population of weeds that emerge and allowing<br />
more focused control of tough-to-control weeds.<br />
Minimize the Risk of Weed Resistance<br />
u Start clean and control weeds early.<br />
u Use Roundup Ready Technology as your foundation.<br />
u Add other herbicides and cultural practices where<br />
appropriate as part of the Roundup Ready Cropping System.<br />
u Use the right rate at the right time.<br />
u Control weeds throughout the season and reduce the<br />
weed seed bank.<br />
u In-crop, apply Roundup WeatherMAX at a minimum of<br />
22 oz/A, and follow with a second application of Roundup<br />
WeatherMAX if an additional flush of annual weeds occurs.<br />
u Roundup WeatherMAX may be tank mixed with products<br />
such as Select MAX ® , Assure ® II or Poast Plus ® if you<br />
suspect the Italian ryegrass is resistant to glyphosate.<br />
Roundup Ready flex Cotton and<br />
Roundup Ready Cotton<br />
u Start clean with a burndown herbicide or tillage. Tank<br />
mix Roundup WeatherMAX with dicamba or 2,4-D<br />
(consult label for plant back timing).<br />
u Apply a preemergence residual herbicide, such as<br />
fluometuron (Cotoran ® ) or diuron (Direx ® ), at the<br />
recommended rate.<br />
u In-crop, apply Roundup WeatherMAX at a minimum of<br />
22 oz/A tank mixed with PARRLAY for residual control<br />
of some grass and broadleaf weeds.<br />
u Roundup WeatherMAX may be tank mixed with products<br />
such as Select MAX, Assure II or Poast Plus if you suspect<br />
the Italian ryegrass is resistant to glyphosate.<br />
Rate your Risk, Know your options.<br />
www.weedtool.com<br />
u Answer 10 field-related questions<br />
u Get your risk rating score<br />
u Discover how to lower your risk<br />
u Learn best practices for reducing general weed<br />
resistance risks<br />
Report incidences of repeated non-performance of any <strong>Monsanto</strong> branded herbicide to<br />
your local <strong>Monsanto</strong> retailer or call 1-800-RounduP.<br />
1This fact sheet is issued to clearly describe use recommendations permitted under FIFRA Section 2(ee) as not being inconsistent with product labeling, or is issued to highlight an approved use<br />
from the product labeling. It is a violation of the federal law to use any registered pesticide product in a manner inconsistent with its labeling. Read and follow all precautions and use instructions<br />
contained within the labeling. The applicable labeling for all products must be in the possession of the user at the time of application. Some recommended pesticide products are not registered in<br />
all states. Check with the product manufacturer or your dealer for products registered in your state. The distribution, sale or use of an unregistered pesticide is a violation of federal and/or state law<br />
and is strictly prohibited.<br />
these recommendations are for all states except texas.<br />
ALWAYS READ AND FOLLOW LABEL DIRECTIONS: Roundup Ready ® crops contain genes that confer tolerance to glyphosate, the active ingredient in Roundup ® agricultural herbicides. Roundup<br />
agricultural herbicides will kill crops that are not tolerant to glyphosate. Harness ® brands and Degree Xtra ® are restricted use pesticides and are not registered in all states. The distribution, sale or use<br />
of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. Check with your local <strong>Monsanto</strong> dealer or <strong>Monsanto</strong> representative for the product registration in your<br />
state. Harness ® , Degree Xtra ® , Roundup ® , Roundup Ready ® , Select MAX ® , PARRLAY, and Roundup WeatherMAX ® are registered trademarks of <strong>Monsanto</strong> Technology LLC. All other trademarks are<br />
the property of their respective owners.<br />
© 2008 <strong>Monsanto</strong> Company 5F-8L-08-3138