NDSU Crop and Pest Report
Weeds


ISSUE 8  June 20, 2002

 

LATE FOXTAIL OPTIONS IN BARLEY

The most common herbicide to control green and yellow foxtail in barley is Puma. Puma cannot be applied to barley once jointing begins. Jointing usually occurs with six-rowed types between the 5 and 5 ½ leaf stage. This is not the case with Conlon, a two-row type. Conlon often will begin jointing by the 4 ½ leaf stage. Spraying Puma on barley after jointing can cause moderate to severe injury and result in stunting and stem breakage.

Achieve is the only POST grass herbicide labeled on barley that can be applied past tillering but no later than prior to the boot stage. If spraying for foxtail is delayed and barley begins to joint then Achieve would be the only choice.

Kent McKay
NDSU Extension Agronomist
North Central R&E Center, Minot

 

MOSS CONTROL IN STOCK TANKS AND STANDING WATER

Algae in stock and nurse tanks can be a nuisance for both animals and for chemical application especially with hard water. Adding copper sulfate to the water will take care of the problem until the tank is refilled with fresh water. The process must then be repeated.

Dissolve 1 ounce of copper sulfate in 1 pint of water in a glass jar. Add 0.25 pt/1000 gallons of water. The copper sulfate will not affect herbicide and weed control.

An alternative for nurse tanks is to paint the entire tank black. This eliminates the sunlight requirement which prevents algae growth.

 

TWO ND STATE LABELS FOR GOAL HERBICIDE

ND Dept of Ag has issued a special local needs registration (SLN) to Dow AgroSciences, enabling North Dakota landowners to continue using the herbicide Goal 2XL to control kochia in shelterbelts and windbreaks. A second SLN was also issued to Dow that will allow mint growers to use Goal 2XL for kochia control.

These registration were approved because there are no effective herbicides registered for use on shelterbelts and windbreaks or in mint fields that adequately control kochia. ND had previously issued SLNs to Rohm & Haas Co., which sold its agricultural chemical business, including Goal® 2XL, to Dow in 2001.

Applicators must follow all instructions, precautions and warnings on the product label and have a copy of the supplemental labeling in their possession during application.

 

REMINDER: 2002 IS LAST YEAR FOR CYANAZINE PRODUCTS

Ag retailers carrying products with the cyanazine (Bladex) chemistry are reminded that 2002 is the last year for sale, use or distribution of Bladex® 4L, Bladex 90DF, Cypro1, Extrazine® II 4L, Extrazine II DF and Cypro AT1 herbicides. Phase out is due to the high standards of environmental stewardship and importance for retailers and customers to meet the requirements for application rate, set-back distance and other precautions as well as phase-out dates. The rate limit of 1 pound of active ingredient per acre applies to cyanazine from all sources. However, when state and/or local requirements differ from the label, the more restrictive requirements apply.

 

PESTICIDE MAKER AND EPA CHANGE LABEL FOR LOW-VOLUME SPRAYERS

EPA has approved a Puma label amendment by Bayer/Aventis to allow application in low-volume sprayer technology. Grower concerns about legal use of herbicides at below label water volume rates has been made.

ND Ag Commissioner Roger Johnson wrote to Bayer (formerly Aventis) and six other manufacturers in May asking them to revise their postemergence herbicide labels with info. regarding low-volume application. Earlier, he had written EPA asking the agency to re-assess its 20-year-old policy of using below label water volumes in light of new tech. and a good database of several herbicides developed by NDSU Weed Scientists. The ND Dept of Ag anticipates that other pesticide manufacturers will amend their labels to allow use at reduced water volumes.

Commissioner Johnson also recently met with regional and Washington-based EPA officials in Denver, CO, and encouraged them to change to their policy since there has been considerable improvement in reduced-volume application spraying equipment in the last 20 years and many producers are using sprayer technology with low water volumes. Last March, Johnson warned North Dakota producers that they may be in violation of the law, if they followed the instructions provided by the sprayer manufacturers, rather than instructions printed on the label. Some of the sprayer manufacturers claimed users could save money on pesticide costs when using the low-volume sprayers by using a higher concentration of a pesticide in the spray mix, and consequently applying less water to the crop. However, growers who followed the equipment instructions not only risked violating federal and state pesticide laws but also risked voiding the pesticide warranty.

In addition to Bayer, Johnson also asked other manufacturers, including Dow Agrosciences, Syngenta, DuPont, BASF, FMC Corp. and Valent to add instructions for low-volume applications to their postemergence herbicides.

Weed scientists at NDSU has found equal or greater weed control at water volumes below label recommendations for Pursuit, Raptor, Accent, Assure II, Poast, Select, Achieve, Assert, Discover, Everest, Puma, glyphosate, Harmony Extra, Aim, 2,4-D, and Starane. Agriculture Canada research shows increased efficacy with lower water volumes with Assert, Assure II, Avenge, Ally, Bronate, 2,4-D amine, MCPA amine, glyphosate, Poast, Select, and others. For herbicides not enhanced by low water volumes, Canadian research found lower weed control from Reglone (diquat) and a certain formulation of Achieve. In Canada, a new formulation was

Achieve was introduced with a label allowing application at 5 gpa.

Remember to follow current label directions when determining water volume rate.

 

EPA'S DRIFT REDUCTION PROPOSAL

Perhaps some of you have read of the proposed ruling by EPA to limit any pesticide application when wind is greater than 10 mph. The proposed ruling by EPA that attempts to eliminate pesticide spray drift was studied in-depth by scientists at the University of Nebraska. According to the study, the days from April 15 to May 20 averaged just more that 5 hours a day when spraying would be legal under the proposed ruling. EPA says it has received more than 5,000 comments and it will rewrite the rule taking those comments into account.

Maybe North Dakota would have 5 hours a week when spraying would be legal!

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


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