1996 Weed Control Guide Updates ---- ---- ------- ----- ------- The 1996 North Dakota Weed Control Guide contains many modifications from previous editions. Many of the modifications are listed below: The restricted-use herbicides DoublePlay and TopNotch were added. Many herbicides were added to the "Minimum Interval Between Application and Rain" table. The adjuvant section was revised and now includes effect of spray water pH on herbicides and average effect of adjuvants on Roundup. Herbicide/Insecticide Tank-mixes and Herbicide/Fungicide Tank-mixes sections were added. A table showing minimum storage temperatures for herbicides was also added. Small Grain Section 1. Bronate price will be reduced 16% in 1996. 1 pint of Bronate will now cost $5.75 to $6. 2. Sulfonylurea herbicide application timing with 2,4-D or 2,4-D + Banvel has been clarified. 3. Canada thistle and field bindweed (creeping jenny) is now listed as control from sulfonylurea herbicide + 2,4-D/Banvel treatments. 4. Finesse and Finesse/2,4-D/Banvel tank-mixes were added to the wheat section. Finesse is a 5:1 ratio or 62.5% Glean (chlorsulfuron) and 12.5% Ally (metsulfuron). Registration of Glean in North Dakota was discontinued in 1993 because of kochia (and potentially other weeds) resistance to sulfonylurea (SU) herbicides. A similar competitive product was registered immediately after Glean lost its registration in ND and kochia resistance to SU herbicides has not decreased since 1993. As with any herbicide, strategies to minimize weed resistance must be followed. (See "Herbicide Resistance" section in Weed Control Guide). 5. Carbyne was deleted from the small grain section. 6. Assert SG, a dry formulation of Assert was added. 7. Assert + Avenge tankmix was added. 8. Harmony Extra was added to oat section. 9. Revision of "Small Grain Preharvest" Section. Some 2,4-D products can be applied to barley and rye, for example, Weedar 64, Weedone 638, Weedone LV4, Weedone LV6. Roundup RT + Banvel for small grain was added preharvest under a special North Dakota Supplemental label. Corn Section 1. Added DoublePlay, a premix of Eradicane (EPTC + safener) and Surpass (acetochlor + safener). 2. Added TopNotch, a micro-encapsulated formulation of Surpass (acetochlor + Safener) for reduced or no-till. 3. Added Sencor (metribuzin) at 1.6 to 2 oz 75DF/A or 2.4 to 3 fl oz 4F applied POST with Banvel/Clarity, Buctril, 2,4-D or other herbicides labeled for tankmix use. Sencor at 1.6 to 2 oz 75DF/A or 2.4 to 3 fl oz 4F can be applied POST Directed with Banvel, 2,4-D, or Buctril using drop nozzles to direct spray below the corn whorl and upper leaves. Sencor + Banvel or Buctril has given excellent control of most annual broadleaf weeds in NDSU field tests. 4. Added Tough (pyridate), a selective herbicide for POST control of kochia, pigweed, and sunflower. Tough must be applied with another broadleaf herbicide for wide-spectrum broadleaf weed control. Effective on sulfonylurea resistant kochia. 5. Added Permit (halosulfuron), a sulfonylurea herbicide used at 0.66 to 1.33 oz DF/A applied POST in corn for control of nutsedge, sunflower, common and giant ragweed, common cocklebur, Venice mallow, and kochia. Permit provides excellent control of nutsedge and velvetleaf but must be tank-mixed with another broadleaf herbicide for control of common lambsquarters, pigweed and other weeds. Degradation of Permit increases as soil pH increases which is different from many sulfonylurea herbicides. Follow label directions for rotational follow crops. Battalion (halosulfuron + safener) has been labeled for soil application in corn but will not be actively promoted in ND. Both products are 75DF. 6. Added Scorpion III (Broadstrike (flumetsulam) + Stinger (clopyralid) + 2,4-D acid) at 0.25 lb WDG/A. Formulated as an 84.3% wettable granule packaged in water soluble packets with each packet treating 2 acres. Apply POST to corn up to 8 inches tall (measured to the top of the whorl). Scorpion III provides excellent, economic ($7 to $8/A) control of a wide range of broadleaf weeds including sunflower, kochia, Russian thistle, pigweed spp., common lambsquarters, common and giant ragweed, mustard spp., marshelder, and nightshade spp. Scorpion III has provided excellent control of most broadleaf weeds in NDSU field tests, including common cocklebur and suppression of Canada thistle. 7. Basis (rimsulfuron + thifensulfuron) at 0.33 oz 75DF/A was added. It can be applied to 4-leaf (2 collar) corn for foxtail, barnyardgrass, redroot pigweed, wild mustard, common lambsquarters, and annual smartweed control. Basis will control all grasses that Accent controls plus crabgrass. Basis has provided varying levels of control of common cocklebur and Canada thistle in NDSU field trials. Basis is a 2:1 ratio of rimsulfuron (Matrix) and thifensulfuron (Pinnacle). Basis will be formulated as a 75DF in 4 acres/water soluble packets. Basis contains 0.167 oz ai rimsulfuron and 0.33 oz Pinnacle (0.083 oz ai thifensulfuron). NDSU did not field test Basis before it was commercially registered in 1995. However, Basis appears to require good soil moisture for adequate weed control. Basis provides best weed control when applied to young, actively growing weeds, during moist, warm conditions, with good soil moisture conditions. Weed control may be reduced if weeds are stressed. A cultivation or sequential application of Accent may be made 14 days or more after Basis application. Basis will burn down grasses quicker than Accent. Basis cost approximately $11/A at 0.33 oz DF/A. Because of the low rate which Basis is labeled, DO NOT use Basis at lower than labeled rates. Many crops can be planted the year following application. See label for crop rotation restrictions. 8. NOT IN WEED CONTROL GUIDE: Exceed (prosulfuron + primisulfuron (Beacon)) was labeled in corn in 1995 Exceed is a premix of two long residual sulfonylurea herbicides. Exceed is not intended to be used in ND because primisulfuron may carryover and injure small grains the year following application. Exceed has provided excellent control of many broadleaf weeds in mid- west field trials. Peak (prosulfuron) was registered in 1995. Peak is a SU herbicide that is a component in Exceed herbicide with labeled intended in wheat, barley, grain and forage sorghum, rye, oat, and proso millet. Peak and Exceed have a long residual and carryover may injure broadleaf crops more than two years following application. Peak and Exceed should not be used in ND. 9. Added Poast - ONLY ON POAST TOLERANT CORN. It will be used to control problem grasses in corn: wild proso millet, field sandbur, quackgrass, woolly cupgrass, etc. Antagonism occurs when tank-mixing with broadleaf herbicides in corn for full spectrum weed control. Soybean Section: 1. Added Resource (flumiclorac) for use on corn and soybean. Resource is very effective on velvetleaf only. Resource may control common lambsquarters less than 1.5 inches tall. Resource was not included in the corn section of the 1996 weed control guide because more effective postemergence options are available (2,4-D, Banvel, Basis, Buctril, Sencor, Scorpion III). Resource was added to the soybean section with Pursuit because Pursuit provides poor common lambsquarters control. Resource only controls common lambsquarters less than 1.5 inches tall. 2. Added Pursuit + Cobra for common ragweed control. 3. Added Roundup Ultra formulations for use on Roundup Ready Soybeans. Canola, Crambe, Rapeseed and Tame Mustard Section: Added Poast - Use only on Rapeseed, Canola, and Crambe. Same restrictions as with other broadleaf crops. Lentil Section: Added Assure II at 5 to 10 fl oz/A for postemergence grass control. Field Pea Section: 1. Added Pursuit at 2 fl oz/A under special North Dakota labeling. Must have label in possession at time of application. Under same label as the North Dakota dry bean label. 2. Added Prowl at 2.4 to 3.6 pt 3.3EC/A. Sugarbeet Section: Added Prism at 13 to 17 fl oz/A for postemergence control of annual grasses and 17 to 34 fl oz/A for quackgrass control. Active ingredient is same as Select. Valent has done the same thing as BASF with POST grass products. A lower priced product is labeled in soybeans and a higher priced product containing the same active ingredient labeled in specialty crops. -------------- -------------- -------------------- ------------ Herbicide Crop Rate Cost/A lb ai/A (product/A) -------------- -------------- -------------------- ------------ Sethoxydim Poast Plus 1EC Soybean 0.2 (1.6 pt/A) $8.80 Poast 1.5EC Specialty Crops 0.2 (1 pt/A) $12.50 Ultima 160 Sugarbeet, flax, 0.2 (20 fl oz/A) $8.50(?) 1.3EC dry bean, canola, potato Clethodim Select 2EC Soybean 0.094 (6 fl oz/A) $8.20 Prism 0.94EC Sugarbeet 0.094 (13 fl oz/A) $14.00(?) Quizalofop Assure II Soybean, Lentils 0.05 (8 fl oz/A) $7.50 Sugarbeet (1996) 0.05 (8 fl oz/A) $7.50 Specialty Crops 0.05 (8 fl oz/A) $7.50 (1996+) Alfalfa and Legume Forages: Pursuit at 3 to 6 fl oz/A for established and establishment of alfalfa. NDSU research has shown control of over 17 major broadleaf weeds with Pursuit + Sun-It II at 2 fl oz/A + 1.5 pt/A ($12.30/A). Pursuit + Sun-It II should cost approximately and Pursuit + Sun-It II at 3 fl oz/A + 1.5 pt/A is $17.25/A. Pursuit has 30 day preharvest interval. Pasture, Rangeland and CRP 1. Changed name of this section to be more consistant with wording on herbicide labels. 2. Incorporated the CRP section into the Pasture and Rangeland section because of similarities in herbicide use. 3. Added Amber. 4. Added Transline, a lower priced formulation of clopyralid. Vegetation Control for CRP Breakout: Considerations prior to breakout: Information on vegetation management when breaking land out of CRP is limited. Consequently, few field researched recommendations are available. A similar situation for comparison is breaking-out established pasture into cropland. Heavy vegetation produced from many years of growth without grazing or haying will make cultivation almost impossible. For most situations, haying in the summer and/or burning in the fall will help remove much of the vegetation found in CRP. Most CRP land will need to be plowed for best results. Relying on cultivation will not give satisfactory results. A herbicide application made several weeks prior to plowing will reduce the amount of vegetation if burning is not used. These mechanical and cultural vegetation control methods should be followed by a vigorous weed control program the following spring. Roundup Ultra/RT and Glyphos should be applied 14 to 21 days prior to tillage. A second application at 2 pt/A about 3 weeks after the first application will be necessary to provide adequate control. Addition of AMS will improve weed control. Refer to label for adjuvant use. Addition of 2,4-D or use of Landmaster BW will increase Canada thistle control but decrease grass control. CRP grasses and forbs may become a problem in the planted crop. Addition of AMS to Landmaster BW will improve weed control. Landmaster BW will control perennial weeds, such as leafy spurge and Canada thistle better than Roundup Ultra/RT applied alone but grass species are more tolerant to Landmaster BW than Roundup Ultra applied alone. CRP grasses and forbs may become a problem in the planted crop. Chemical Weed Control in Shelterbelts: 1. Added additional information on Goal. 2. Specify use of Pricep 4L and Caliber 90 only on conifers, not deciduous trees species. Special Weed Problems 1. Added the names of the noxious and prohibited weeds of North Dakota. 2. Added Arsenal for common milkweed control in noncropland. 3. Added sulfonylurea 2 and 3-way tankmixes in Canada thistle and field bindweed sections. 4. Added Prism to quackgrass section. 5. Deleted atrazine from Canada thistle and quackgrass sections. Lower use rates are too low. Paragraphs 1. DuPont no longer provides a Laboratory Recrop Bioassay (LRB) Service. 2. New herbicides added to Table containing Rotation Restriction for Crops Grown in North Dakota. 3. Herbicide resistance section updated and expanded to include new information. 4. Table on Herbicide Classification and Mode of Action for Resistant Weed Management revised to reflect a more accurate classification of herbicides. New herbicides and premixes have also been added. 5. Finesse has been added for foxtail control or suppression. This may be important with Treflan resistant green foxtail since Finesse represents a different mode of action. 6. Black nightshade paragraph (M24) section revised (look at end of soybean section). 7. Revised Restrictions on Feeding and Grazing of Crops Treated with Herbicides section. 8. Table of Trade Names was revised to include new herbicides. Herbicide prices for 1995 were included. 9. Table of Herbicide Spray Additives revised to include new products and prices. 10. Adjuvant Specificity Company Roundup Accent Pursuit BASF Products ---------- ------------- ------------ ----------------- ------------- Cenex Class Act Class APM-28 Class Prefer 28 Rosens Sensation Impressive Impressive Loveland Dispatch AMS Dispatch 2N Choice Extra Dispatch Flame