Professional Crop Advisor’s Weed Control Update Scott Hagood – Virginia Tech January 7, 2010 Verona, Virginia

1. Professional Crop Advisor’s Weed Control Update Scott Hagood – Virginia Tech January 7, 2010 Verona, Virginia

2. Gone but not forgotten! Virginia Tech football loses a key competitive advantage on the field, with the media, and in recruiting. The Hokies will miss you!

4. VT Weed Science Web Page WEED ID GUIDE AQUATIC WEEDS E-MAIL ACCESS TO SPECIALISTS EXTENSION PUBLICATIONS • HONEYVINE MILKWEED • HORSENETTLE • TRUMPETCREEPER • HEMP DOGBANE • ANNUAL RYEGRASS • MUGWORT • COMMON PASTURE/HAYFIELD WEEDS • ITCHGRASS HERBICIDE MODE OF ACTION - WEED RESISTANCE DIAGNOSTICS VIA DIGITIZED IMAGES ACCESS TO ALL 2010 PEST MANAGEMENT GUIDES ~1,200 EXTERNAL SITES LINK TO THIS VT SITE ~8,000,000 “HITS” ANNUALLY

5. Source: Virginia Native Plant Society – Potowmack Chapter – August 2009 Newsletter SAMBUCUS CANADENSIS–“I AM NOT A WEED!” What if you were googling along and found your name on a Virginia Tech website listed as an aquatic weed?! http://www.ppws.vt.edu/scott/weed_id/aquatics.htm. You would not be amused. In fact you might write a strong letter or at least an email to the offending organization. Dear Virginia Cooperative Extension Service: I am writing to clear my good name. I was taken aback to find that I have been listed on your website as a weed. I want you to know that I am a native American, who was here long before Virginia was even a colony. I occur in every single county in this Commonwealth and in almost every state in the country. I have bountiful flowers and abundant fruits. My flowers are beloved by numerous pollinators in late spring. Please notice the red-spotted purple butterfly in the photo below. Native bees are also ardent feeders from my nectar, helping me reproduce. Solitary bees also use my old, hollow stems to nest in. And according to the Virginia Soil and Water Conservation Service, my berries are eaten by 48 species of birds. Even humans love me. In fact my genus name comes from the Greek sambuce, an ancient musical instrument, and refers to my soft pith, which is easily removed so people can make flutes and whistles from the stems. Southern tribes also used the stems to make blowguns. Humans use my berries to make jellies, jams, fritters, catsup, pie, vinegar, syrup, juice, and even soup. Plus, they can make wine. Here is a recipe: Easy Elderberry Wine Recipe 5 lbs elderberries, stripped from their stems1 gallon boiling water3 lbs granulated sugar1 wine yeast packet1 cup chopped raisins½ cup lemon juice½ cup orange juice1 teaspoon yeast nutrient Place the elderberries into a large plastic fermentation container that can hold boiling water. Add raisins, lemon juice, orange juice, and yeast nutrient. Pour boiling water into container and stir. When cool, squeeze mixture to release juices. Let sit for 24 hours. Add 2 lbs sugar and the wine yeast packet. Stir and cover. Let sit for 3 to 5 days. Strain liquid into a glass fermentation container and add remaining 1 lb of sugar. Stir. Let ferment in a dark, warm location for 1 week. Strain into another glass container and let sit for another 6 weeks. Pour into wine bottles and seal. Wine will be ready for consumption in 6 months. Prolific I am; but a weed, I am certainly not. I know you are an agricultural and technical university, and want to provide information for farmers, but they need to know about the benefits of native plants, too. Your motto is “Knowledge for the Commonwealth;” so I am pleased to hear that Virginia Tech may be updating its information on weeds, natives, and other plants this year. I’ll be keeping an eye on it. Sincerely, Sambucus canadensis (the elderberry)

6. Small Grains – Powerflex (pyroxsulam), Axiom (flufenacet + metribuzin) and Starane Ultra (fluroxypyr) • Corn – Valor SX (flumioxazin) + simazine burndown, Capreno (thiencabazone + tembotrione) POST • Soybeans – Flexstar GT (fomesafen + glyphosate) PRE and POST, Ignite 280 (glufosinate) Burndown and in-crop POST • Pasture/Forage – Chaparral, Chateau • General – New site of action table, generic alternatives table, and resistant weed management section

7. Most of the “generic” versions of herbicides in this table have not been tested by weed extension specialists in the Mid-Atlantic region. • If you are considering the use of a generic version of a herbicide, be sure to read the label of the generic product. The generic version of a herbicide may not have the same formulation as the brand-name product, thus use rates may not be the same. Generics may not be labeled for all the same uses as the brand-name product; or supplemental labeling may not cover the generic products. The generic formulation may not be registered for use in all states. Levels of manufacturer support in instances of unsatisfactory herbicide performance may vary. It is your responsibility to read and understand the label of all pesticides that you use.

8. New Table: Herbicide site of action for reducing the risk of developing herbicide-resistant weeds Example entries

9. New Table: Table Selected generic alternative herbicides for agronomic uses Example entries

10. Field Corn – Pre vs. Post Inputs • Soybeans – Pre Programs fb Glyphosate and Glyphosate Tank Mix Partners • Herbaceous and Woody Perennial Weed Control in Pastures/Hayfields • Annual Grass Control in Pastures/Hayfields • Italian Ryegrass Control in Small Grains • ALS-Resistant Common Chickweed in Small Grains • Tolerance of Grass and Legume Forage Species to Newer Pasture Herbicides • Chateau for Weed Control in Alfalfa

11. Capreno: Laudis + thiencarbazone - HPPD + ALS chemistry - 3.0 fluid oz/acre + atrazine – COC + UAN or AMS. • Kixor: salflufenacil – PPO chemistry – BASF -Integrity and Sharpen in 2009 field trials. • Integrity: salflufenacil + dimethenamid - broad spectrum PRE treatment “without the need for atrazine”. • Sharpen: salflufenacil – broadleaf burndown and residual for corn, soybean, small grains. • Cadet: fluthiacet – POST velvetleaf up to 36” (also POST soybean label)

13. Late Season Grass Control in Corn?

16. Select Max most effective on 2-3 inch corn. Six fluid ounces plus NIS and AMS. Six day replant interval to corn. • Gramoxone Inteon most effective on 4-6 inch corn. Apply 2-3 pints in combination with a Photosyestem II inhibitor (Sencor: 4-6 ounces, Lorox: 1 pint, atrazine: 1 quart). • Ignite 280 at 22 – 29 fluid ounces. Ignite has not been as consistent as Gramoxone for the control of volunteer corn.

17. 2,4-D or other early preplant treatments

18. Dicamba use in your soybean production areas?

19. IGNITE 280 IN LIBERTY LINK SOYBEANS

20. IGNITE 280 IN LIBERTY LINK SOYBEANS

21. DuPont Optimum GAT Herbicide Combinations

22. New Entry – Soybeans (In Crop): Ignite 280 2.34 L 22 -36 oz/acre (glufosinate-ammonium) • Apply only to soybeans designated as Liberty Link. • Applications may be made from emergence up to but not including the bloom growth stage. • Apply at 22 fl oz/A. A second application or a tank mix application with a residual herbicide will be required to control weeds that have not emerged at the time of application. If conditions prohibit timely initial application, a single application of up to 36 fl oz/A may be made to soybeans within the growth stages described above. • If Ignite 280 is used in a burndown application, no postemergence applications of Ignite 280 may be applied. • Ignite 280 has been observed to antagonize grass control with postemergence grass herbicides. WEEDS CONTROLLED : Many annual broadleaf weeds, control or suppression of some annual grasses, and suppression of many perennial weeds in conventional and no-till soybean production systems

23. New Entry – Soybeans (Burndown): Ignite 280 2.34 L 22 -36 oz/acre (glufosinate-ammonium) • Ignite 280 may be applied as a burndown treatment prior to the planting or emergence of any conventional or transgenic soybean variety. • Apply a minimum of 29 fl oz/A to young, actively growing weeds. • Warm temperatures, high humidity, and bright sunlight improve the performance of Ignite 280. Weed control may be reduced when applications are made to weeds under stress from drought or cool temperatures. • If Ignite 280 is used in a burndown application, no postemergence applications of Ignite 280 may be applied. • Ignite 280 must be applied with ammonium sulfate at the rate of 3 lb/A. WEEDS CONTROLLED: Many annual broadleaf weeds, control or suppression of some annual grasses, and suppression of many perennial weeds existing at the time of no-till establishment of any conventional or transgenic soybean variety.

24. New Entry – Soybeans (PRE): Flexstar GT 3L 3.0 – 4.5 pt/acre (fomesafen + glyphosate) • Preplant surface or preemergence applications of Flexstar GT will provide burndown control of most annual broadleaf weeds and grasses via the glyphosate component plus residual control or suppression of certain germinating broadleaf weeds as listed • Moisture is necessary to activate Flexstar GT for residual control, and effectiveness will be reduced if sufficient activation rainfall is not received within 7 days of application. • No additional adjuvants are required with Flexstar GT. Apply in combination with ammonium sulfate in areas where this addition is used with glyphosate products. • Crop oil concentrate, methylated seed oil, or nonionic surfactant may be added to enhance control of difficult to control weeds. • Ignite 280 must be applied with ammonium sulfate at the rate of 3 lb/A. WEEDS CONTROLLED: Common lambsquarters, galinsoga spp., nightshade spp., palmer amaranth, pigweed spp., prickly sida, purslane, common ragweed, and partial control of common cocklebur, giant ragweed, and morningglory spp.

25. New Entry – Soybeans (POST): Flexstar GT 3L 3.0 – 4.5 pt/acre (fomesafen + glyphosate) • Apply to glyphosate-tolerant soybeans only. Postemergence applications of Flexstar GT will provide burndown control of most annual broadleaf weeds and grasses via the glyphosate component plus residual control or suppression of certain germinating broadleaf weeds. • Refer to the label for herbicide rates for specific weed species and growth stages. Thorough coverage is required for effective control. • No additional adjuvants are required with Flexstar GT. Apply in combination with ammonium sulfate in areas where this addition is used with glyphosate products. • Crop oil concentrate, methylated seed oil, or nonionic surfactant may be added to enhance control of difficult to control weeds, but may reduce crop tolerance. WEEDS CONTROLLED: Most annual grasses and broadleaf weeds, control or suppression of many perennial weeds, and residual control or partial control of certain broadleaf weeds germinating at the time of application.

26. Weed Control in Small Grains – 2010 • No-till burndown treatments are critical, and vary significantly. 2,4-D an important component • Osprey, Axial XL, and Finesse Grass and Broadleaf afford excellent ryegrass control • AE-F130060: Atlantis - mesosulfuron + iodosulfuron • Speedwell control requires Finesse or the combination of Osprey plus Harmony Extra SG • No effective treatments for red deadnettle • Common chickweed control failures have been reported

27. SMALL GRAIN HERBICIDES HOELON AXIAL XL BUCTRIL AIM PROWL H2O AXIOM FINESSE GRASS AND BROADLEAF HARMONY EXTRA SG HARMONY SG FINESSE PEAK MAVERICK OSPREY POWERFLEX 2,4-D BANVEL/CLARITY STARANE ULTRA

28. Small Grain Herbicides: Mode of Action PSI HARMONY EXTRA SG HARMONY SG FINESSE PEAK MAVERICK OSPREY POWERFLEX BUCTRIL PPO ALS AIM PROWL H2O Seedling Growth 2,4-D BANVEL/CLARITY STARANE ULTRA Growth Regulators HOELON AXIAL XL FINESSE GRASS AND BROADLEAF AXIOM ACCase Multiple

29. Harmony Extra 75 DF 0.3 – 0.6 oz becomes Harmony Extra SG 50 SG 0.45 – 0.9 oz • TNT Broadleaf (Gowan) retains the same 75 DF formulation and rates as original Harmony Extra • Harmony GT 75 DF 0.5 – 0.6 oz becomes Harmony SG 50 SG 0.75 – 0.9 oz • Unity (Gowan) retains the same 75 DF formulation as the original Harmony GT • 2EE Label – NC, SC, VA – Harmony Extra SG – 2 applications – 0.75 oz - PRE + POST – wild garlic.

30. Postemergence control of common chickweed with sulfonylurea herbicides in Virginia small grains has generally been very effective. The standard treatment for the control of common chickweed and other winter annuals has been the commercially formulated combination of thifensulfuron-methyl plus tribenuron-methyl. • In the 2007-08 growing season, insufficient control of common chickweed was observed in response to this treatment in two Virginia counties: New Kent (NK) and King William (KW). Two collections of mature common chickweed plants were made at each of these locations, and designated NK1, NK2, KW1, and KW2. Mature common chickweed plants were also collected in Montgomery County, Virginia, and designated as the wild type (WT). • The objectives of this research were to 1) evaluate the susceptibility of F1 common chickweed progeny derived from each of these five collections to a range of application rates of thifensulfuron-methyl, 2) evaluate the susceptibility of this progeny to other sulfonylurea herbicides and to ALS-inhibiting herbicides from other chemical groups, 3) confirm the heritability of resistance, if observed, and 4) conduct field trials to identify alternative control strategies for common chickweed which exhibits reduced sensitivity to sulfonylurea herbicides.

31. Figure 1. Effect of thifensulfuron application rate on fresh weight of common chickweed from wild type (WT), New Kent (NK), and King William (KW) collections at 30 DAT. * indicates significant reduction in WT fresh weight relative to other sources, α = .001. Fresh Weight (% of control) * * * * * * * * Thifensulfuron Rate

32. 1/4X 1/2X 1X 2X 4X 8X 32X 0X NK1 WT 16X

33. With heritability confirmed – case reported in the International Survey of Herbicide Resistant Weeds, March 2009 – First report in the United States.

34. Common Chickweed Control with Preemergence Valor Treatments - New Kent County, Virginia – April 24, 2009 Current label requires 30 day early preplant interval. 15 day interval for Fall 2010? No injury to wheat at this location. Significant injury observed in 2008-09 and 2009-10 trials at the Eastern Shore AREC.

35. Common Chickweed Control with Delayed Preemergence Treatments - New Kent County, Virginia – April 24, 2009

36. Common Chickweed Control with Postemergence Treatments New Kent County, Virginia – April 24, 2009

37. ACCase resistant (diclofop). Current options for ACCase resistant ryegrass are ALS inhibitors or preemergence treatments. ALS resistance reported in North Carolina and suspected in Virginia.

38. New Entry – Wheat (POST): PowerFlex 7.5 D 3.5 oz (pyroxsulam) • Apply to wheat in late fall or early spring from the 3-leaf stage to jointing. • Apply to grass weeds from the 2 - leaf to 2 - tiller stage and broadleaf weeds up to 2 inches tall or 2 inches in diameter. • Non-ionic surfactant (0.25%to 0.50%) or crop oil concentrate (0.8%) are required. • May be applied in spray solutions containing liquid nitrogen (not more than 50% of spray solution and not exceeding 30 pounds of nitrogen per acre). • Do not mix with dicamba, 2,4-D amine or MCPA amine as they may antagonize grass control. It is permissible to tank mix with 2,4-D ester or MCPA ester. WEEDS CONTROLLED: Italian ryegrass, common chickweed, mouseear chickweed, hairy vetch, henbit, common lambsquarters, mustard species, field pennycress, redroot pigweed, shepherdspurse, Russian thistle, white clover, Virginia pepperweed

39. New Entry – Small Grains (POST): Starane Ultra 2.8 L 0.3- 0.4 pt/acre (fluroxypyr) • Apply to small grain from the 2-leaf stage up to and including flag leaf emergence for control of actively growing broadleaf weeds, but before weeds are 8 inches tall. • Do not apply more than 0.7 pint per acre of Starane Ultra per growing season. • Do not graze treated fields for 7 days after application. • Do not apply closer than 14 days before cutting of hay or 40 days before harvesting of grain and straw. • Do not use if cereal crop is underseeded with a legume. WEEDS CONTROLLED: Common chickweed (including ALS-resistant biotypes), cocklebur, hemp dogbane, prickly lettuce, common ragweed, sunflower, velvetleaf and suppression of jimsonweed, lambsquarters, morningglory species, nightshade species, and field bindweed.

40. New Entry – Wheat (DPRE): Axiom 68 DF 4.0 – 10.0 oz/acre (flufenacet + metribuzin) • Apply from spike to 3-leaf growth stage of wheat. • Use 4.0 to 6.0 oz/acre on coarse soils and 6.0 to 10.0 on medium and fine soils. • Axiom may be tank-mixed with and/or applied sequentially with any other herbicides which are registered for use in winter wheat unless prohibited on the label of the tank-mix or sequentially applied product. • Do not apply in tank-mixtures with crop oil concentrates, vegetable and/or petroleum oils as crop injury may result. WEEDS CONTROLLED: Annual bluegrass, bromegrass, common chickweed (suppression - including ALS-resistant biotypes), henbit, Italian ryegrass (suppression), mouseear chickweed, and others.

41. 2,4 - D BANVEL / CLARITY CROSSBOW STINGER CIMARRON (ALLY) CIMARRON MAX CIMARRON PLUS REDEEM GRAZON P + D REMEDY SURMOUNT PASTUREGARD AIM MILESTONE - FOREFRONT

44. Chaparral: Dow – Milestone + Ally • DPX-MAT28: DuPont – aminocyclopyrachlor • Pastora: DuPont – Accent + Ally • Prowl H2O

45. New Entry – Pasture: Chaparral 71.6 D 1.0 -3.3 oz/acre (aminopyralid plus metsulfuron) • Intended for broadleaf weed control in permanent grass pasture • Apply in combination with crop oil concentrate or nonionic surfactant • Do not use on Timothy hay or other cool-season grasses grown for hay • Do not use more than 2 oz/A on tall fescue • Carefully observe label directions regarding use of treated plant residue and manure and regarding rotational crop restrictions WEEDS CONTROLLED : MILESTONE plus CIMARRON LISTS: Aster spp., bedstraw, biennial thistle spp., bittercress, bitter sneezeweed, black locust, black medic, black-eyed Susan, blackberry, brackenfern, burdock, buttercup spp., Canada thistle, Carolina geranium, chamomile, common chickweed, common purselane, common ragweed, common sunflower, common vetch, common yarrow, chicory, cinquefoil, clover spp., corn cockle, cocklebur, cowcockle, crownvetch, cutleaf eveningprimrose, dandelion, dewberry, dock, fiddleneck, filaree, fleabane, goldenrod spp., hawkweed spp., henbit, honey locust, honeysuckle, horsenettle, ironweed, knapweed spp., kudzu, lambsquarters, lespedeza spp., mayweed spp., mexicantea, mullien, mustard spp., multiflora rose, oxeye daisy, partridgepea, pigweed spp., plantain spp., ragwort, red sorrel, sowthistle spp., shepardspurse, sicklepod, sida spp., smartweed spp., Spanish needles, spiny amaranth, starthistle spp., teasel, yellow woodsorrel, wild carrot, wild parsnip, wooly croton, and others.