Slide Presentation

TITLE    (click title to view slides)
2002: Managing Tropical Spiderwort in Roundup Ready Cotton

AUTHOR
A. S. Culpepper
J. T. Flanders
A. C. York
University of Georgia and N. C. State

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TABLE OF CONTENTS
  1. Managing Tropical Spiderwort (Commelina benghalensis) In Roundup Ready Cotton
  2. Spiderwort response to Roundup UltraMax
  3. Typical RR Cotton Grower Program
  4. Tropical Spiderwort Infestation
  5. Spiderwort's Rank as Georgia's Most Troublesome Weeds in Cotton
  6. Tropical Spiderwort Infestation
  7. Tropical Spiderwort Infestation
  8. Tropical Spiderwort Infestation
  9. Objectives
  10. Location
  11. Materials and Methods
  12. Application Information
  13. POST Over-the-Top: Whole Plot
  14. Tropical Spiderwort Infestation
  15. Tropical Spiderwort Control with Topical Applications.
  16. UltraMax vs Dual Magnum
  17. Tropical Spiderwort Control with Topical Applications.
  18. POST Directed Treatments: Subplot
  19. Mid-Season Tropical Spiderwort Control with Directed Applications (21 DAT).
  20. Prowl PRE, glyphosate POST, glyphosate Directed
  21. Prowl PRE, glyphosate POST, MSMA Directed
  22. Late-Season Tropical Spiderwort Control with Directed Applications.
  23. Four Most Effective Spiderwort Systems at Harvest.
  24. Conclusions
  25. Conclusions



SLIDE CONTENTS
  1. Managing Tropical Spiderwort (Commelina benghalensis) In Roundup Ready Cotton A.S. Culpepper, J.T. Flanders, and A.C. York University of Georgia and N. C. State
  2. Spiderwort response to Roundup UltraMax* *Pictures 15 d after treatment. No plants died from any treatment. Six inch at time of application.
  3. Typical RR Cotton Grower Program: 1) DNA at planting 2) Roundup at 3- to 4-leaf 3) Roundup at layby
  4. Tropical Spiderwort Infestation Red = severe Orange = moderate Green = light Yellow = exist Gray = not found 2002 Prostko agent survey
  5. Spiderwort’s Rank as Georgia’s Most Troublesome Weeds in Cotton 1998: not ranked* 2001: ninth* 2003: number 1 *Published in SWSS annual proceedings.
  6. Tropical spiderwort infestation, Cairo, GA, 2001.
  7. Grady Co. 2002
  9. Objectives Compare POST over-the-top herbicide options for spiderwort control Compare POST-directed herbicide options for spiderwort control Develop a systems approach for spiderwort management
  10. * Location Two on farm trials in 2001 and 2002 * * *
  11. Materials and Methods Cultivar: various RR cultivars Planted: May or June Plot size: three or four rows by 30 feet Design: split plot Treatments: factorial arrangement with 3 early POST by 8 directed options Reps: 3 or 4 reps
  12. Application Information DNA applied at planting at each location POST over-the-top treatments applied at 15 GPA POST directed treatments applied at 15 to 20 GPA Treatments applied at 3 MPH Tropical spiderwort 1 to 4 inches, avg. 2 to 3 inch Weed control visually estimated throughout season
  13. POST Over-the-Top: Whole Plot Roundup UltraMax (0.75 lb ae) Roundup + Staple (0.032 lb ai) Roundup + Dual Magnum (0.95 lb ai)
  15. Tropical Spiderwort Control with Topical Applications. 53 c 60 b 80 a % control
  16. UltraMax @ 4 leaf cotton + Dual Magnum 1 pt/A 1) Dayflower emerged 3 to 7 day after 4 leaf application. One inch of rain within 48 hr. 2) Prowl applied PRE. No layby.
  17. Tropical Spiderwort Control with Topical Applications. 49 b 48 b 69 a % control 53 c 60 b 80 a *Late-season control pooled over directed applications.
  18. POST Directed Treatments: Subplot Roundup UltraMax (0.75 lb ae) + Direx (0.625 lb ai) + Valor (0.032 lb ai) + Aim (0.012 to 0.016 lb ai) + Harvade (0.3 lb ai) MSMA (2 lb) + NIS + Direx (1 lb ai) + Valor (0.064 lb ai) Timely & precise applications were made with less than 9% herbicide injury noted.
  19. Mid-Season Tropical Spiderwort Control with Directed Applications (21 DAT).
  20. Prowl pre, glyphosate POST, glyphosate directed. 17 day after directed.
  21. Prowl pre, glyphosate POST, MSMA directed. 17 day after directed.
  22. Late-Season Tropical Spiderwort Control with Directed Applications. 44 c 42 c 80 a % control Roundup + Aim + Direx + Harvade + Valor MSMA + Direx + Valor Data pooled over four locations. Directed main effect means presented. 57 b 43 c 64 b 45 c 64 b 76 a
  23. Four Most Effective Spiderwort Systems at Harvest. Pooled over 4 locations.
  24. Conclusions 1) Early POT applications of glyphosate + Staple are more effective than glyphosate alone on emerged spiderwort. 2) However, residual control from Dual appears to be more critical in the system.
  25. Conclusions 3) MSMA was more effective than glyphosate at layby. 4) Direx and Valor were the most effective directed tank mix options due to residual spiderwort activity.