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ISSUE 4   May 24, 2001

 

2001 NDSU WEED TOUR

The 2001 NDSU Weed Tour will be held Tuesday, July 3, 2001. Below is the tentative schedule with locations and times.

8:30 - 11:30 - NW-22 Research Farm, Fargo, ND  (SW corner of I-29 and County Rd 20)
  
Plot booklets will be available along with a guided tour of field research experiments. Researchers will be present to explain the objectives of the experiment, discuss study treatments, and answer questions.
   Experiments include: Wild oat and broadleaf weed control in wheat, weed control in flax, field pea, chick pea, and sunflower, carryover, biennial wormwood control and biology studies, application technology with variable rates, speed, and gallonage, and nozzle studies.

11:30 - 1:00 - Lunch - to be determined.
Will be free to all tour attendees and will be paid by NDSU Extension Weed Science Project.

1:00 - Travel to NDSU Agronomy Seed Farm, Casselton, ND
Weed control in corn, soybeans, and sunflower.

OR

1:00 - Travel to North of the Airport (County Rd 20) for tour of sugarbeet weed control plots. Dr. Alan Dexter will lead a tour for those interested in sugarbeet weed control research.

 

STAGE OF WEED AND ROTATION OF HERBICIDES ALWAYS IMPORTANT

An evaluation of several biotypes of the rigid ryegrass in Australia including that biotype that has gained resistance to glyphosate (Roundup) has allowed farmers more information on the resistant mechanism in weeds. Research revealed that application between the two-leaf and tillering stages of a susceptible biotype of the grass made the weed slightly more susceptible to Roundup application than if the herbicide was applied at other growth stages. Roundup is a nonselective herbicide that has been used without the appearance of any resistant weed biotypes for the past 20 years. The new biotype of rigid ryegrass in a field in Northern Victoria, Australia that has recently shown resistance to Roundup last year after the chemical was used consistently for 15 years on the location does not show susceptibility at any growth stage. The resistant weed when tested exhibited nearly 10-fold more resistance than susceptible biotypes of this same grass to Roundup. The resistant weed was also resistant to three different salt formulations of glyphosate. It was also nearly three-fold more resistant to Hoelon, a grass control herbicide with a different mode of activity, but ironically was susceptible to other commonly used selective and broad-spectrum herbicides such as trifluralin (such as Treflan), Amber, Surflan, Zorial, metribuzin, Diuron, Simazine, Poast, Fusilade, Liberty or paraquat. Shoot and root growth with the resistant rigid ryegrass was observed through many experiments and results so far reveal hat the resistance mechanism might be associated more with the shoot than the root through possibly internal metabolism and resistant target-site enzymes as well as foliar uptake and translocation within the plant or even within cells. Consider herbicide rotation and application timing on fields in order to prevent weed resistance from developing.

Denise McWilliams
Extension Crop Production Specialist

dmcwilli@ndsuext.nodak.edu

 

BROADLEAF CROP HERBICIDE UPDATE

Ally (DuPont)

Mode of action: ALS inhibitor
a.i.: metsulfuron
Crops: Pasture, rangeland, and CRP
Comments: Labeled for aerial application on pasture, rangeland, and CRP.

Amplify (Monsanto)

Mode of action: ALS inhibitor
a.i.: cloransulam
Crops: Soybean
Comments: Monsanto will market FirstRate under the name Amplify and sell it with Roundup products for control and residual control of large-seeded broadleaf weeds.

BASF

Phase out: Detail, TriScept, Tri-4, Scepter OT, Steel, Celebrity, Galaxy, Manifest, Storm.

Boundary (Syngenta)

Mode of action: Acetanilde +Photosynthetic inhibitor
a.i.: metolachlor + triazine
Crops: Soybean
Comments: Contains 6.3 lb/gallon of active isomer of metolachlor + 1.5 lb/gallon of metribuzin. The rate of 1.5 pt/A of Boundary gives 1.24 pt/A of Dual II Magnum and 6 oz DF/A of Sencor. Compared to Turbo it is more metolachlor and less metribuzin. Marketed in the Roundup Ready soybean system.

Clearfield Crops Registration (BASF)

Mode of action: ALS inhibitor
a.i.: Beyond, Beyond + Arsenal
Crops: Canola, dry bean, dry pea, alfalfa, wheat, and sunflower
Comments: The imazamox product used in Clearfield wheat, canola, and sunflower will be know as Beyond. Same active ingredient as Raptor. EPA is reviewing registration of all crops listed as a package. When granted all crops listed will be cleared for use. Clearfield sunflower may be available via Section 18 in 2002.

DuPont

Phase out: Pinnacle, Canopy, Reliance STS.
2 (ee) label issued to allow Steadfast tankmixed with Distinct, Tough, or Stinger plus petroleum oil adjuvant or with Distinct or Clarity plus NIS.
2(ee) label issued to allow tankmix of Accent Gold + Basis Gold at Ĺ rates.

Express (DuPont)

Mode of action: ALS inhibitor
a.i.: tribenuron
Crops: SU resistant sunflower.
Comments: Non-GMO. Developed by Jerry Miller and DuPont independent of each other. Residue trials will be conducted in 2001 with Section 18 possible in 2002 and full registration in 2003-4. The resistant line is specific to Express. Several other SUís and all Imi herbicide seriously injure or kill the Express resistant sunflower.

Gauntlet (FMC)

Mode of action: PPO + ALS inhibitor
a.i.: sulfentrazone + chloransulam
Crops: Soybean
Comments: Apply preemergence. Does not control grass weeds. Use with a grass program. Offers very good full-spectrum annual broadleaf weed control. Significant cost savings from buying each product independently.

Outlook (BASF)

Mode of action: Acetamide (Mode of action unknown)
a.i.: dimethenamid-P (active isomer). 6 lb ai/A
Crops: Same crops as Frontier.
Comments: Use rates are 55% of Frontier rates. Will replace Frontier in future. Pending registration on potato and sugarbeet.

Pursuit (BASF)

Mode of action: ALS inhibitor
a.i.: imazethapyr
Crops: Several
Comments: Registration approved for PPI and PRE application in lentil and chickpea.

Select (Valent)

Mode of action: ACCase inhibitor
a.i.: clethodim
Crops: Canola
Comments: Maximum rate labeled is 5 fl oz. PHI on sugarbeet reduced to 40 days. Registration on mint and field peas expected in 2002.

Sonalan (Dow)

a.i.: ethalfluralin
Crops: Supplemental labeling allows use chemigation in dry beans and sunflower through pivot, lateral move, or end row sprinkler. Directions are specific for this use.

Starane (Dow)

a.i.: fluroxypyr
Crops: Labels revised and amended on all Starane products adding BMP for control of dicamba resistant kochia biotypes, adjuvant information, revised rate table to include reduced rates.

Ultra Blazer (BASF)

Mode of action: PPO inhibitor
a.i.: acifluorfen-Na salt
Crops: Soybean
Comments: A new formulation of Blazer with Ion Charge Technology that supposedly produces soybean response similar to Flexstar but less than Cobra. No NDSU studies have been conducted with Ultra Blazer.

Valor 51DF (Valent)

Mode of action: PPO inhibitor - Cell membrane disruptor
a.i.: flumioxazin
Crops: Soybean
Comments: Soil applied at 2 to 3 oz/A. Rates INCREASE as soil OM decreases. Similar to Authority/ Spartan herbicide except low risk of carryover. Research in alfalfa (established only), dry bean, field pea, mint, potato, onion and some vegetable crops are in development. Burndown will be allowed <30 days prior to planting wheat, corn, and sunflower. Provides E common mallow control also shows excellent algae control (on roofs). Shows white mold control in soybean. Very insoluble and absorption does not change with soil pH as sulfentrazone.

Richard Zollinger
NDSU Extension Weed Specialist
rzolling@ndsuext.nodak.edu


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