1. Weed Control Update For Grain Crops J. R. Martin & J. D. Green Extension Weed Science Plant & Soil Sciences University of Kentucky

2. CORN HERBICIDE UPDATE Callisto 4 SC (mesotrione) –Approved for sweet corn Camix 3.67L (S-metolachlor + mesotrione) –Atrazine sensitive watersheds Radius 4L ( flufenacet + isoxaflutole) –Similar to Equip 32DG Resolve 25DF (rimsulfuron) –Pre or Post up to 12” 5 collars Gramoxone Inteon 2L (paraquat) –Gramoxone Inteon (2 lb/gal) –Gramoxone Max (3 lb/gal)

3. Roundup Ready (GA21 event) Broadcast through V8 /30” Max single rate 0.75 lb ae/A –Roundup Original @ 2 pt –Touchdown Hi-Tech @ 1.2 pt (NK603 event) Broadcast through V8 / 30” Max single rate 1.13 lb ae/A –Roundup Orginal @ 3 pt –Roundup WeatherMAX @ 2 pt Drop nozzles 30” to 48” SOURCES OF TOLERANCE FOR RR-Corn Roundup Ready 2

4. Sequence 5.25L (glyphosate + S-metolachlor) –Burndown treatment Gramoxone Inteon 2L (paraquat) –Gramoxone Inteon 2lb/gal vs Gramoxone Max 3lb/gal GRAIN SORGHUM HERBICIDE UPDATE

5. Canopy EX (chlorimuron + tribenuron) –Fall / Spr burndown (no later than 45 days before planting) –Need to include 2,4-D –Mostly broadleaf weeds Synchrony XP (chlorimuron + thifensulfuron) –Synchrony XP 28.4DF vs Synchrony STS 42DF –Post & Early Preplant Sequence 5.25L (glyphosate + S-metolachlor) –Burndown + Post (up to 3 rd trifoliate) Gramoxone Inteon 2L (paraquat) –Gramoxone Inteon (2 lb/gal) vs Gramoxone Max (3lb/gal) SOYBEAN HERBICIDE UPDATE

6. BENEFITS May eliminate spring burndown. Limits weedy vegetation at planting. Help soils warm & dry sooner (usually). Spreads work load. Helps Manage SCN? DRAWBACKS Risk of soil erosion. May require advanced commitment to a crop. Cannot rely on residual activity into next season. May not eliminate spring burndown FALL APPLICATIONS FOR CORN

7. CORN RESPONSE POTENTIAL INJURY RATING (0-3 scale) Rating = 0 –Atrazine –Glyphosate (RR-corn) –Liberty (LL-corn) Rating = 1 –Buctril –Expert –ReadyMaster ATZ Rating = 2 –Callisto - Hornet –Dicamba - Marksman –Distinct - Option –Equip - Permit Rating = 3 –Accent - 2,4-D –Accent Gold - Exceed –Aim - Lightning –Basis Gold - Spirit –Beacon - Steadfast –Celebrity Plus - Steadfast ATZ Source: UK AGR-6

9. Corn Tassel & Ear Seed Set SOURCE: Herbek / Martin / Green 2005 Non-treated CheckLightning Treated

10. HERBICIDE RESISTANT WEEDS IN KY Smooth PigweedConfirmed –Photosystem II inhibitor (1987) –ALS inhibitors (1992) –Photosystem II + ALS inhibitors (2000) Johnsongrass –ACCase inhibitors (1991) Marestail / Horseweed –EPSP inhibitor (2002) Italian Ryegrass – ACCase inhibitors (2004)

11. Glyphosate Resistant Weeds * Palmer AmaranthGeorgia Buckhorn Plantain S. Africa * Common Ragweed Missouri Goosegrass Malaysia Hairy Fleabane S. Africa & Spain * Marestail USA (10 states) Italian ryegrass S. America * Rigid Ryegrass Australia, S Africa, California (Source: Int. Survey of Herbicide Resistant Weeds) * Found in US WEEDLOCATION

12. Types of Formulations of Glyphosate ProductSaltLb ai/galLb ae/gal Roundup Original, Glyphomax Plus IPA43 Extra Credit 5IPA53.75 Durango Glyphomax XRT IPA5.44 Touchdown TotalK4.17 Roundup Original MAX Roundup WeatherMAX K5.54.5 Touchdown Hi-TechK5