Crop and Pest Report: Weeds

ISSUE 2 May 11, 2006

FAIRY CANDELABRA /YELLOW WHITLOWWORT - NUISANCE WEEDS

Fairy Candelabra questions and specimens are coming in for ID. This little plant is amazing. After people find out its name they want to know how to kill it. It doesn't matter because it will be dead in a week or so anyway. We (the weeds group) actually think it would be a good cover crop. It emerges quickly, is small in stature, has a shallow root system, doesn't use much soil moisture, dies before much time goes by in the spring, and doesn't interfere with crop growth.

Glyphosate or any herbicide will not control it, because has already bolted, has flowered, and now setting seed. As we know from field pennycress, shepherdspurse, and wild mustard, once winter annuals bolt they become very difficult to kill. This makes sense since they are nearing the end of their life cycle.

Fairy Candelabra

WEED ID AND WEED CONTROL WEB SITES

The following web sites are excellent sources of weed ID, weed control, and herbicide information.

1. NDSU Weed Science Web Site:

http://www.ag.ndsu.edu/weeds

Web address is on the cover of the 2006 Weed Control Guide.

2006 Weed Control Guide

2006 NC Vegetable Weed Control Guide

2006 Herbicide Price List

1978/79 and 2000 ND Weed Surveys

ND Pesticide Use Surveys

Extension Weed/Herbicide Extension Publications

NDSU Extension Crop Production Publications

2006 Section 18 status

CDMS Pesticide Label Search

Herbicide Resistant Weed Web Site

Weed Identification

Previous Crop and Pest Reports

Other academic and UDSA weed information

2. NDSU Invasive Weed Science Web Site:

http://www.ag.ndsu.nodak.edu/invasiveweeds

Publications, database and other information concerning identification and control of ND noxious and invasive weeds.

3. NDSU Pesticide Training and Certification Program

http://www.ag.ndsu.nodak.edu/aginfo/pesticid/pesticid.htm

All EPA approved ND herbicide Section 18, 24c, and 2(ee) registrations have been posted on the web.

5. NDSU Plant Diagnostic Lab:

http://www.ag.ndsu.nodak.edu/diaglab/

6. Pesticide Labels

http://www.cdms.net/manuf/manuf.asp

A free web site with all current pesticide and adjuvant labels. Also contains state, 2ee, and supplemental labels.

http://www.greenbook.net/

Known in weed science circles as the "Green Bible" or "Blue Bible" contains all labels for most all pesticides currently labeled. Free service allows search and printing of all labels. Uses Adobe Acrobat Reader, which can be downloaded from this site.

http://www.kellysolutions.com/nd/

This site is where the ND Dept of Ag shows all ND pesticide registrations. One can find out if a product has been registered in ND by accessing this site.

Richard Zollinger
NDSU Extension Weed Specialist
r.zollinger@ndsu.edu

COMPARISON TO POST GRASS HERBICIDES IN WHEAT

In years past, when we had only 3 or 4 major postemergence grass herbicides that were labeled in wheat we could remember the specifics about them. Puma controlled green foxtail very well but required higher rates for yellow foxtail and wild oat. Discover controls foxtail and wild oat, but cannot be used on barley. Everest controls foxtail, wild oat, and mustards and can give residual grass control with adequate soil activiation from precipitation.

Now we have a few more POST herbicides, like Beyond in Clearfield wheat. In addition, we have some different grasses infesting parts of North Dakota: Persian darnel, downy borme, Japanese brome, and foxtail barley. A comparison guide, developed by Greg Endres, NDSU Area Extension Agronomist, is shown below as a quick reference.

NDSU Small Grain Grass Herbicide Quick Reference Guide (May, 2006)
	Axial	Discover	Everest	Puma	Rimfire
Crop	Winter and HRS wheat, barley	HRS and durum wheat	HRS and durum wheat	Wheat and barley	Wheat
Crop stage	2-leaf to boot	2-leaf until prior to boot	emergence to prior to jointing	Wheat: emergence to 60 days before harvest. Barley:1-4 leaf	1-leaf to flag leaf emergence
Grass weed stage	1-6 leaf + 3 tillers	1-5 leaf foxtail and 1-6 leaf wild oat	up to 4 leaves	1 leaf to 2 tiller	1 leaf to 2 tiller
Mode of Action	ACCase Inhibitor	ACCase Inhibitor	ALS inhibitor	ACCase Inhibitor	ALS inhibitor
Application rate/A	8.2 fl oz	3.2 and 4 fl oz; NG 12.8 and 16 fl oz	0.3-0.6 oz	0.33-0.66 pt	1.75-2.25 oz
Cost ($/A)	12.50	12.50-15.50	9.50-14.50	7.50-15	8.25-10.50
Adjuvant	Adigor 9.6 fl oz/A (co-pack)	DSV (co-pack); MSO 0.25% may be added	NIS 0.25% or basic pH blend 1% if no EC or ester broadleaf herbicides	mefenpyr safener (prepackaged)	MSO 1.5 pt/A, or NIS 0.5% + UAN 1-2 qt/A, or basic pH blend 1%
Residual for weed control	No	No	Yes	No	Yes
GPA ground	5 - 10	5	5 - 10	5-10	10-15
GPA Air	5	3	3 - 5	5	5
Rainfast (hours)	0.5	0.5	1	1	4
PHI (days)	60	60	60	wheat - 60, barley - 57	71
Crop rotation restrictions beyond next crop season (months after app)	No	No	field pea - 11; oat - 18; chickpea and lentil - 24	No	corn, crambe, CRP grass, potato and sugarbeet - 12
Grass weed control:
Wild Oat	Control	Control¹	Control²	Control¹	Control²
Green foxtail	Control	Control¹	Control	Control¹	Suppression
Yellow foxtail	Control	Control¹	Suppression	Control¹	Suppression
Barnyardgrass	Suppression	Control	Suppression	Control	Control
Downy Brome	None	None	Suppression	None	Suppression
Japanese Brome	None	None	Control	None	Suppression
Persian Darnel	Control	Control	Suppression	None	Suppression
Foxtail Barley	None	None	None	None	Suppression
Quackgrass	None	None	Suppression	None	Suppression
Selected annual broadleaf weed control	No	No	Yes	No	Yes
Tank mixtures	see labels

¹Except ACCase resistant plants.
²Except ALS resistant plants.