Blair Griffin University of Arkansas Cooperative Extension Service

1. Pasture And Hay Weed Control Blair GriffinUniversity of ArkansasCooperative Extension Service

2. Forage Weed Control • Herbicide timing for winter/spring weed control • Herbicide timing for summer weed control • Buckhorn plaintain • Woolly croton • 2,4-D substitutes

3. Forage Weed Control • Appearance

4. Forage Weed Control • Appearance • Yield

5. Forage Weed Control • Appearance • Yield • Quality

6. Forage Weed Control • Appearance • Yield • Quality • Value

7. Grazing for Weed Control • Small are more palatable • Many weeds have comparable protein levels to forages • Good Fencing and cattle numbers are needed

8. Mowing • Too late to prevent competition. • No selectivity. • Perennials will re-grow. Multiple sprouts. • May prevent weed seed production. • Consistency is key to effective weed control with mowing.

9. What is the Economic Threshold? Rule of thumb: When weeds are more than 20% of the pasture. Woolly croton

10. Forage Weed Problems • Lack of management • Fertility • Lime • Overgrazing • Mowing • No weed control • 5 to 10% of Arkansas pastures sprayed • Lack of weed control knowledge • part-timers • hobbyists

11. Do I spray or fertilize first? • Spray first. • Control existing weeds. • Begin soil-test based lime and fertilizer program.

12. Easy broadleaf weeds in grass pastures winter weeds in dormant bermuda Not so Easy summer grasses in bermudagrass broadleaf weeds in legumes sedges fescue in bermudagrass Pasture Weed Control with Herbicides

13. Pasture Weed Control in Arkansas • Spring application of 2,4-D 1 qt/acre with a cluster nozzle. • Butter cup # 1 problem, blooms in April • 2,4-D provides cheap, effective control • Cluster nozzle works well in windy conditions • Easy on white clover

14. Broadleaf Weed Control Plenty of Options Timing Application Inexpensive Poor Control Timing Application

15. Broadleaf Weed Control • Metsulfuron • Ally • Cimarron • Cimarron Extra • Martins Clean Pasture • Patriot • MSF

16. Winter Weed Control Herbicide Application • Dec – March • Weeds emerge in the fall • Earlier you treat, easier to control weeds • Retreat missed areas • Weather (wind, rain) • Weather Myths (temp, rain) Common Winter Weeds • Buttercup • Thistles • Henbit • Buckhorn Plaintain • Wild Garlic

17. Spray this size Not this size

18. Buttercup • Treat when small (2-4”) Dec – March • Usually one flush per season • 2,4-D, Grazon, Weedmaster 1-2 pts/acre • Ally/Cimarron 0.25 oz/acre

19. Thistle • Late fall or early spring application • Treat at rosette leaf stage • 2,4-D ester - 2.0 qt./acre • WeedMaster - 2.0 pt./acre • Grazon P+D - 2.0 pt./acre Bull thistle Musk thistle

20. Henbit • Treat Dec - Feb • Cimarron 0.30 oz/ac excellent control (100%) • Grazon P+D 1 qt/ac • GrazonNext 1 qt/ac good control (80-90%) • 2,4-D 1 qt/ac poor control (60%)

21. Buckhorn Plaintain • Perennial • Emerges in the fall • Rosette stage through the fall and late spring • Flowers in May

22. Buckhorn PlaintainFall Treatments Treated October 20 • GrazonNext 1 qt/ac • Grazon P+D 1 qt/ac • Weedmaster 1qt/ac • 2,4-D 1 qt/ac • 95-100% control March 20

23. Buckhorn PlaintainSpring Treatments Treated March 16 • Grazon P+D 1 qt /ac • GrazonNext 1 qt/ac • 2,4-D 1 qt/ac • Weedmaster 1 qt/ac • 90-95% control

24. Summer Weed Control Herbicide Application • May – July • Multiple flushes • Treat when plants are small • Good soil moisture increases control • Use surfactant • Multiple applications

25. Bitter Sneezeweed • Apply when 1 to 3 in. tall. • 1-2 pts/acre: • 2,4-D • Grazon P+D • Weedmaster • Cimarron Max 1 pt + 0.25 oz • Cimarron 0.25 to 0.33 oz/ac

26. Pigweed • Treat when small (2 to 4 inches) early May • Ally/Cimarron/MSM 60 0.25 to 0.33 oz/acre • Grazon P+D, Weedmaster, 2,4-D - 1-2 pts/acre, Cimarron Max 1 pt + 0.25 oz • Germinates all summer. Repeat applications needed.

27. Pigweed • Multiple flushes • 2 – 3 applications during the summer for adequate control

28. Horsenettle / Bullnettle • Good control • Cimarron 0.25 oz • 2,4-D 1 -2 qt • Grazon P+D 1 qt • Need 100% control for several years

29. Woolly Croton • Emerges in early to mid May • Well adapted to both high and low fertility fields. • Drought Stress • Apply herbicides when goatweed is 2– 4” tall

30. Woolly Croton • Grazon P+D 1 qt/ac • GrazonNext 1 qt/ac • Weedmaster 1 qt/ac • 2,4-D 1 qt/ac • Excellent control (95-100%) • Cimarron/Patriot • Good control (80%)

31. Cocklebur • Apply when 1 – 3 in. tall • 1-2 pts/acre: • 2,4-D • Grazon P+D • GrazonNext • Weedmaster • Cimarron/Ally 0.25-0.33 oz/ac

32. Blackberry • Cimarron 0.5 oz/ac • 1% Remedy or PastureGard for spray to wet or 1 qt/ac broadcast • Spray in fall or at full bloom. • Repeat applications needed for complete control.

33. Pricklypear Cactus Spot treatment • 2% v/v Grazon P+D + 0.5% v/v surfactant in water • 1% Tordon 22K or Surmount + 0.5% v/v surfactant in water

34. Surmount 2 qts / ac 65 DAT

35. Greenbriar None of the pasture herbicides are very effective. Repeat applications of Weedmaster at 2 qts per acre provide at least short term control. Add surfactant.

36. 90 DAT Weedmaster 2 qt / acre

37. Alternatives to 2,4-D Products with 2,4-D Products without 2,4-D Cimarron/Patriot/Ally Milestone Remedy Pastureguard Pastora • 2,4-D • Grazon P+D • GrazonNext • Weedmaster • Cimarron Max • PasturAll

38. Combine… • Mowing • Grazing • Fertilization • Herbicides • ……in an integrated approach to weed management

39. Questions?