1 / 49

Basics of Turfgrass Weed Management

Basics of Turfgrass Weed Management. Tim R. Murphy Crop and Soil Sciences The University of Georgia. What is a Weed?. A plant out of place A plant whose virtues have yet to be discovered A flower in disguise. Is this plant a weed???. Common ragweed decreases crop yields, allergen

Download Presentation

Basics of Turfgrass Weed Management

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Basics of Turfgrass Weed Management Tim R. Murphy Crop and Soil Sciences The University of Georgia

  2. What is a Weed? • A plant out of place • A plant whose virtues have yet to be discovered • A flower in disguise

  3. Is this plant a weed??? • Common ragweed • decreases crop yields, allergen • Poison ivy • skin rashes, fruit consumed by birds • Tall fescue • desirable turf and forage grass • a weed in warm-season turfgrasses

  4. Human beings decide which plant is a WEED!!!!

  5. Why are weeds an annual problem? • Seed and vegetative structure dormancy • Prolific seed producers • Spread of seed

  6. Weed seed survival insured by: • Hard seed coat (testa) • Deep burial • After ripening mechanisms • Germination inhibitors

  7. Weeds are prolific seed producers. Seed/Plant Broadleaf plantain 36,000 Lambsquarters >30,000 Crabgrass 53,000 Texas Panicum 23,000 Annual Bluegrass 2,000

  8. Weeds - Nutsedge Spring 43,560 1 ft. Fall X 3,000,000 Plants 4,000,000 Tubers Acre Acre

  9. Introduced weeds • Johnsongrass • Common lespedeza • Crabgrass • Broadleaf plantain • Water-hyacinth

  10. Factors affecting seed germination • Oxygen • Light • Scarification • Temperature • Water

  11. Why control weeds?

  12. Control vs. Eradication Control -Process of limiting a weed infestation to a level that is economically or aesthetically beneficial. Eradication -Elimination of all plants and plant parts of weed species from an area.

  13. Weeds • Compete with desirable plants for sunlight, moisture and nutrients • May exert allelopathic effects • Reduce yields or quality of harvested product

  14. Why do we control weeds in turfgrasses?

  15. Turfgrass Weeds • Reduce quality - leaf width, shape, color differences • Reduce density - outcompete turfgrasses, can lead to erosion • Decrease aesthetic value or utility of the turfgrass. - difficult to mow, disrupt uniformity of playing surfaces, safety considerations, attract insects

  16. Develop A Plan • Goals • Methods • Economics • Alternatives • Benefits

  17. The Goal Establish and maintain a high quality, nearly weed-free turfgrass.

  18. Integrated Weed Management • Methods • Preventive • Cultural • Biological – not available in turfgrasses • Mechanical • Herbicides

  19. Preventive Methods • State and Federal laws • Weed-free seed, sod, sprigs • Weed-free topsoil, topdressing • Clean equipment • Field borders

  20. Cultural Methods • Adapted turfgrasses • Fertility • Cultivation • Water management • Insect and disease control

  21. Southeast U. S. Turfgrasses

  22. Soil Fertility Effects on Weeds • Low N - legumes, mosses, speedwell • High P - annual bluegrass • High N - common chickweed, ryegrass, annual bluegrass • Low soil pH - red sorrel, broomsedge

  23. Weeds Favored by High Soil Moisture • Sedges - purple nutsedge, green kyllinga • Rushes • Annual bluegrass • Mosses, algae • Alligatorweed • Pennywort

  24. Weeds Favored by Low Soil Moisture • Prostrate spurge • Poorjoe • Common lespedeza • Prostrate knotweed

  25. Weeds Favored in Compacted Soils • Annual bluegrass • Goosegrass • Prostrate knotweed • Common lespedeza • Path rush

  26. Weeds may indicate a nematode problem • spurges • Florida pusley • prostrate knotweed

  27. Mechanical Methods • Mowing • Hand removal

  28. Why does mowing control tall-growing weeds? • Reduces apical dominance of main stem • Basal buds initiate growth • Continued clipping depletes root carbohydrates • Prevents weed seed formation

  29. Why does mowing not control low-growing weeds? • Primary growing point is located beneath the mower blade.

  30. Kentucky Bluegrass

  31. Herbicides • Herbicide – a chemical used to control, suppress or kill plants. • Preemergence – applied before weed seeds germinate • Postemergence – applied to emerged weeds

  32. Herbicides • Turf species vary in tolerance • Weed species vary in susceptibility • Turfgrass species and weed identification is critical to herbicide selection!!!!

  33. Maintain Healthy Turfgrass • Manage the roots to have good shoots • Soil testing is a must! • Utilize cultural practices (fertility, irrigation, mowing height, etc.) to improve stress tolerance • Keep mower blades sharp ! • Use the best species and cultivars for your location

  34. Identify the Weed Problem • READ textbooks and periodicals • Keep a diagnostic tool kit - hand lens, etc. • Know the life cycle of the pest (What temp. does a specific weed seed germinate?) • Is the weed the cause or effect of the problem? • Confirm your diagnosis

  35. Weed Thresholds - ?? • Site - putting green, lawn, etc. • People - expectations • Weed - population dynamics • Budget - dollars

  36. Scouting Sites • Use zig-zag pattern • Make random stops

  37. Scouting Sites • Identify weeds and life cycle • Record observations by area - ornamental beds - turfgrass areas * front lawn * back lawn

  38. Scouting Sites • Record density by species • Low - 1 to 10% • Medium - 11 to 20% • High - > 20%

  39. When to Scout? • Mid-winter months - winter weeds • Late-April to July - summer weeds • Late summer - assess summer program • Late spring - assess winter program

  40. Developing a Weed Management Program • Prevent weed introduction • Properly maintain turfgrasses • Identify weeds and learn life cycle • Initiate control practices • Preventive • Cultural • Mechanical • Herbicides

More Related