Friday, January 27, 2012

Fine Tuning Cotton Insect Management for 2012

I. Thrips Control
  1. Need for foliar overspray
    • Influenced by planting date primarily but also to lesser degree by night temperature and overall growing conditions
    • Seed treatments planted from early April to about May 10th would benefit from foliar overspray
    • Seed treatments give 21 day thrips suppression as opposed to 28+ days with in-furrow granules
    • What you see with thrips injury above ground is reflective also of underground root conditions and growth
  2. Timing of overspray
    • Most beneficial when most of plants have 1st true leaf about the size of a small finger nail
    • Cotton with 4 or more true leaves usually does not benefit from overspray
  3. Multi state research in 2011 indicated that acephate (Orthene or generics) was equal to or superior to all other choices
    • Certain pyrethroids were a weak choice
    • Bidrin is effective but I would suggest saving for stink bug control. New label limits total use of Bidrin in one season to 1.2 lbs active.
      • New products tested: Benevia (Dupont) and Radiant ( Dow). Both looked very effective but not certain about registration date and cost.
II. Nematode Management

  1. Rotation- peanuts, grain sorghum, corn
  2. Variety selection- PHY367WRF has root knot tolerance
  3. In-furrow granules
    • Loss of Temik
    • Meymik registered on December 22, 2011 (production and supply for 2012 uncertain)
  4. Seed treatments
    • Suggest to use on lower risk fields
    • In high nematode risk fields would be like using a Band-Aid when a tourniquet is needed
  5. Fumigate (Telone)
    • Consider site specific nematicide placement (Precision Ag)
    • Nematodes usually not evenly distributed across field
  6. Deep tillage- grew cotton over 100 years without nematodes being a limiting factor- only since reduced tillage have they become a major problem
III. Plant Bugs

  1. Movement from wild host into cotton influenced by climate
    • Hot/dry results in high peak but short in time
    • Wet/cool spring results in low movement over longer period
  2. Most effective insecticides
    • Acephate (Orthene, generics)- can flare spider mites
    • Bidrin- good but only labeled for post bloom period
    • Centric- effective but hard on beneficials and fire ants
    • Pyrethroids- can flare spider mites
    • Diamond- very effective on immature stage post bloom, especially when tank mixed with one of the above
    • Intruder, Carbine, imidacloprid (Trimax), Belay, Vydate- less effective than others with one application
IV. Plant Bugs + Aphids (July)

  1. Intruder, Carbine, imidacloprid (Trimax, etc.), Centric
  2. Diamond may be combined with the above
V. Mid Season Worm Overspray

  1. May be more important with Phytogen varieties
  2. Timing could be mid July to early August depending on your north to south location
  3. Pyrethroids are a good fit here
  4. If brown stink bugs are also present, may want to select bifenthrin or Bidrin XPII (combination of Bidrin + Bifenthrin) or use highest labeled rate of other pyrethroids
  5. Role of Fire Ants in Cotton
    • Are the dominant beneficial in Alabama cotton today
    • Not only important in conventional systems but also reduces escapes in Bollgard and WideStrike (Example: Mississippi consultants spray BGII on % egg lay)
    • Some chemicals suppress fire ants more than others (Centric, Steward, pyrethroids, imidacloprid)
    • Dr. Tim Reed and I conducted a project at Prattville last season (Poster Presentation)
    • Results show less boll damage on both conventional and genetic cotton with fire ants in system as opposed to no fire ants
      • Numbers on the side represent the number of worm damaged bolls per 45 feet.
      Impact of Fire Ants On Bollworm
      Damage in Alabama Cotton
VI. Fall Armyworms

  1. 2010 and 2011 seasons have produced widespread outbreaks of the “grass” or “rice” strain of the FAW
  2. This strain primarily attacks pastures, hay, grasses and peanuts and are easy to control with most insecticides, including pyrethroids
  3. They do not prefer to feed on cotton or corn
VII. Stink Bugs

  1. Some level of scouting needed for most economical control
    • May need 0-4 sprays ($6-9 each considering application)
    • Could pay for a field scout with savings or reduced damage from stink bugs alone
  2. Most effective scouting is to examine 10-12 day old bolls for internal injury
  3. Use “dynamic” or sliding threshold which considers the number of bolls at risk at a given week of bloom
  4. Possible Reasons for Low Stink Bug Pressure in 2011
    • Winter temperatures (colder than recent winters)
      • Southern green stink bug is very sensitive to cold weather
    • Impact of hot, dry spring on wild host/corn—may have reduced numbers of brown stink bug species
  5.  New Stink Bugs
    • Brown Marmorated Stink Bug
    • Kudzu Bug (soybeans)
    • Red-Banded Stink Bug (soybeans)  

Brown Marmorated Stink Bug

Red Banded Stink Bug
Kudzu Bug

VIII. New Products and Technology

  1. Sulfoxaflor (Transform)- Dow
    • Effective on plant bugs and aphids
  2. Beseige (combination of Karate + Coragen)
    • Effective on broad spectrum of caterpillars (loopers, fall armyworms), plus would have green stink bug activity
  3. Endigo (combination of Karate + Centric)
    • Effective on certain caterpillars, plant bugs, aphids and green stink bugs
  4. Belay- in market place for past two seasons for plant bug/stink bug control
    • Still need more University research to get a good handle on effectiveness
  5. Prevathon (Dupont)
    • One of most active caterpillar insecticides ever developed
    • Excellent residual, depending on rate
    • Very rainfast
    • Should be targeted at egg stage or small larvae
  6. Bayer Twin-Link
    • Contains multiple Bt genes
    • Performs somewhere between WideStrike and Bollgard II for caterpillar control
  7. Bollgard III
    • Under development
    • Third gene is not a Bt so it has multiple modes of action for worms
    • Reduces escapes over Bollgard II and will provide long term resistance management for the genetic technology
  8. Poncho/Votivo Seed Treatment
    • Insecticide + biological nematicide
    • Looked at it in one trial on cotton and could see growth response and earliness, even under low nematode pressure