Slide Presentation

TITLE    (click title to view slides)

AUTHOR
W. C. Johnson, III
Research Agronomist - Weed Science
USDA-ARS
Coastal Plain Experiment Station
Tifton, GA

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TABLE OF CONTENTS
  1. Weed Control and Cantaloupe Tolerance to Halosulfuron
  2. Halosulfuron Basics
  3. Halosulfuron Basics (cont.)
  4. Research on Halosulfuron Since 1995
  5. Weed Control Using Halosulfuron (2/3 oz./A) on Transplanted Cantaloupe
  6. Visual Injury and Crop Yield Using Halosulfuron (2/3 oz./A) on Transplanted Cantaloupe
  7. Weed Control with Halosulfuron (2/3 oz./A) in Transplanted Cantaloupe - Effects of Herbicide Placement
  8. Crop Injury and Yield Response to Halosulfuron (2/3 oz./A) in Transplanted Cantaloupe - Effects of Herbicide Placement
  9. Carroll Johnson’s Opinion on Halosulfuron
  10. Carroll Johnson’s Opinion on Halosulfuron (cont.)
  11. POST Transplanting - Directed Application for Herbicides
  12. Carroll Johnson’s Opinion on Halosulfuron (cont.)
  13. Unanswered Questions
  14. Dan Evarts



SLIDE CONTENTS
  1. Weed Control and Cantaloupe Tolerance to Halosulfuron W. C. Johnson, III Research Agronomist – Weed Science USDA-ARS Coastal Plain Experiment Station Tifton, GA
  2. Halosulfuron Basics Originally, a corn herbicide intended to be a replacement for atrazine Reasonable broadleaf weed control spectrum Good to excellent control of cocklebur, many pigweeds, ragweed, wild radish, and smallflower morningglory Good to excellent control of yellow and purple nutsedge No effect on grasses Can be applied PRE or EPOST Excellent results controlling nutsedge with either application
  3. Halosulfuron Basics (cont.) Little potential for carryover 4 to 12 day half-life in sandy loam soil In contrast, Cadre has 120 day half-life Symptomology PRE applications Does not inhibit seed germination Seedling growing point develops chlorosis and necrosis soon after seedling emergence POST applications Chlorosis: 3-7 days after application Necrosis of growing point: 7-14 days after application Complete death of plant: 14-21 days after application Weed size often determines how fast symptoms develop
  4. Research on Halosulfuron Since 1995 Direct seeded cucumber and watermelon Transplanted cantaloupe and watermelon on polyethylene covered beds Times and methods of halosulfuron application on polyethylene covered beds Residual benefits of halosulfuron applied to watermelon and sweet corn to future double-cropped crucifers
  5. Weed Control Using Halosulfuron (2/3 oz./A) on Transplanted Cantaloupe
  6. Visual Injury and Crop Yield Using Halosulfuron (2/3 oz./A) on Transplanted Cantaloupe
  7. Weed Control with Halosulfuron (2/3 oz./A) in Transplanted Cantaloupe – Effects of Herbicide Placement
  8. Crop Injury and Yield Response to Halosulfuron (2/3 oz./A) in Transplanted Cantaloupe – Effects of Herbicide Placement
  9. Carroll Johnson’s Opinion on Halosulfuron Best weed control spectrum of anything cucurbit growers would ever likely have registered Significantly helps in the overall management of yellow and purple nutsedge Controls several, but not all, broadleaf weed species Application versatility (PRE or POST)
  10. Carroll Johnson’s Opinion on Halosulfuron (cont.) Acceptable crop tolerance among the cucurbit group Most tolerant to least tolerant: Cucumber>cantaloupe=watermelon>squash Safe application timings vary widely among cucurbit crops My preference, based on considerable experience and research data is PRE to weeds but POST-Directed soon after transplanting This is a simple application technique that does not require significant reconfiguration of sprayers
  11. POST Transplanting – Directed Application for Herbicides
  12. Carroll Johnson’s Opinion on Halosulfuron (cont.) Cropping systems that routinely use herbicides such a halosulfuron will dramatically reduce populations of nutsedge since halosulfuron can control tubers. This may actually be the greatest benefit of halosulfuron in cropping systems that include vegetable crops. Halosulfuron should not present a major carryover to other crops, either in single- or double-cropping systems.
  13. Unanswered Questions Refine the application timing by crop Cultivar screening Carryover to double- or rotation-crops Sometimes seen, sometimes not seen – Why??? Interactions among pH, soil type, tillage, and water events We will soon have the qualified personnel in place to answer these questions
  14. Dan Evarts – the technician who makes my off-the-wall ideas work.