Cotton Nematode Management

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Cotton Nematode Management

• Jimmy R. Rich and Charles Overstreet

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Nematode Facts
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Nematodes are HighlyUnderrated Pests

• Most numerous animal (s) in the world
• Are the second most in number of animal species
• Over 6000 known plant-parasitic species
• Nematodes attack all crop plants
• Present in all cotton growing areas of the U.S.

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Nematode Anatomy
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Nematodes in Roots
A.
A. Triccoli
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Plant-Parasitic Nematode Stylet (Spear)
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Plant Nematode Facts

• Mainly plant root parasites
• Very small - mostly microscopic
• Five life stages (plus egg)
• Mostly wormlike in shape
• Some female nematodes swollen
• Life cycle - every 20-30 days
• Some females can produces 300-400 eggs
• Over one season - 1 female 8 billion and more
  nematodes (hence the problem!!)

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Nematodes in Cotton
J.R. Rich
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Major Cotton Nematode Pests

• In order of importance in the U.S.A.
• Southern Root-Knot Nematode,
• Meloidogyne incognita
• Reniform Nematode
• Rotylenchulus reniformis
• Columbia lance
• Hoplolaimus columbus
• Sting Nematode
• Belonolaimus longicaudatus

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Distribution of root-knot nematode
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Distribution of reniform nematode
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Plant and Root Damage Symptoms
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Foliar Damage Symptoms Water and Nutrient Stress

• Premature wilting in spots on plant or field in
  spots
• Leaf yellowing (some)
• Plant stunting (stunted growth)
• Irregular (oval) symptom patterns
• Row patterns rarely evident
• Nutrient deficiency symptoms

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Cotton Field AbandonedDue to Nematode Damage
M. Donahoe
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Young Cotton Stunted by Nematodes
B. Gazaway
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Nematode Damage Following Soil Type Change
B. Gazaway
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Damage on Maturing Cotton
J.R. Rich
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Purpling of Cotton Leaves by Reniform Nematodes
J.R. Rich
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Plant Root Damage

• Stunted roots
• Fewer feeder roots
• Root galling and swelling
• Root cell death or cell malfunction
• Openings for disease organisms

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Root-Knot Nematode Galling on Roots, Not Very
Apparent
J.R. Rich
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Female Root-Knot with Eggs, Root is the Size of a
Pinhead
R.S. Hussey
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Reniform Nematode Females Partially inside
Roots, No Root Galling
Females teased out and laid on top of root
C. Overstreet
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Nematode Damage Symptoms

• When damage symptoms are observed in the field,
  losses have been occurring over several years
• Most times nematodes cause economic losses
  without obvious symptoms
• A small problem this year makes for a large one
  the next year

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Comparison of Nematode Damage Symptoms on Cotton
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Nematode Problem Assessment
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Know Your Nematodes

• Each nematode species is different
• Management techniques should be nematode
  specific
• Rotations must be planned for key nematode
  pests
• Nematicide rates can be adjusted for nematode
  species

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Problem Identification

• Foliar symptoms stunted ovals/decline
• Root symptoms roots galled/stunted
• Cropping history declining yields and previous
  host crops
• Laboratory analysis which nematode type and
  numbers are present

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Nematode Soil Samples Problem ID

• Take anytime during crop maturity and prior to
  planting, best time is soon after harvest
• Can take samples for nematodes when collecting
  soil fertility samples
• Split soil samples, one for nematode analysis and
  one for fertility (1 pint each)
• Remember extra care is required for nematode
  samples

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Handling Nematode Soil Samples

• Sample 8-10 deep if possible
• Sample only in moist soils Not dry or wet
• Only use plastic bags which prevents soil drying
• Do not allow samples to become hot or cold

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Tools for taking nematode soil samples

• Choice of sampling tools
• Plastic bag
• Permanent ink marker
• Bucket

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Ten Acre Sampling Patterns(Take 15 To 20 Cores)
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Managing Cotton Nematodes
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Management Methods

• NEMATICIDES ?
• Rotation
• Sanitation
• Resistance

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Cotton Nematicides

• Temik 15G - Bayer CropScience
• Telone II - Dow AgroSciences
• Avicta Complete Pak- Syngenta
• K-pam or Vapam- Amvac
• Vydate Dupont

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Temik 15G Product Information

• Sold only as a 15 granular formulation
• Formulation usually clay based
• Used at-planting as a band or in-furrow
• Pinhead square side dress applications can also
  be made
• Temik 15G rarely kills nematodes (mainly
  paralyzes them)

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Telone II Product Information

• Sold as liquid formulation only
• Movement by fumigant action in the soil
• Applied preplant injected to 14 inches depth (do
  not apply in clay subsoil)
• Usually applied with a single in-row chisel in
  cotton
• Telone II kills nematodes on contact

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Avicta Comptete Pak Product Information

• Sold only as a seed treatment
• Combination of fungicide, insecticide, and
  nematicide
• Chemicals are present on the seed at the time of
  planting

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Telone, Vydate and Temik Are Restricted Use
Pesticides

• Reminder - both products have specific use
  restrictions!!
• In Florida U.S.A., Temik has special reporting
  and use requirements.
• Temik 15G forms and other requirements can be
  found at FDACS Web Site - http//www.safepesticide
  use.com

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Cotton Nematicide Rates Varies Dependent Upon
Soil Type, Location, Nematode Species

• Temik 15G (In Furrow)
• Ranges from 3.5 lbs/a to 7 lbs/a at the time of
  planting
• Telone II (In Row, Single Chisel)
• Ranges from 3 gal/a to 5 gal/a applied at least
  7 days prior to planting

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Farmer Field Demonstration
No Treatment ?
Telone II ?
M. Donahoe
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Management Methods

• Nematicides
• ROTATION ?
• Sanitation
• Resistance

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Rotation

• Know what nematode(s) are present
• Use poor or nonhosts crops and rotate for at
  least two years
• Consider using a nematicide if rotating only one
  year
• Reniform nematode rotation corn, sorghum, and
  peanuts are nonhosts tobacco and soybeans are
  poor to moderate hosts. Cucurbits are good
  hosts.
• Southern root-knot nematodes have a wide host
  range but sorghum and peanut are fairly resistant.

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Management Methods

• Nematicides
• Rotation
• SANITATION ?
• Resistance

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Sanitation Notes

• Control weeds, many are nematode hosts including
  Morningglory, Florida Pusley, Tropical
  Spiderwort, Nutsedge etc.
• Prevent crop regrowth in peanut and cotton to
  stop nematode population after harvest
• Perennial grass rotation (bahiagrass) does not
  work with weed hosts present

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Nematode Weed Hosts in Bahiagrass Pasture
J.R. Rich
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Frequently Asked Questions
J.R. Rich
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Is GPS/GIS Variable Rate Nematicide Application
Feasible?

• This is doable technology!!
• System Needs
• Accurate nematode population distribution map of
  a field, alternatively, a yield monitor map
  linked to nematode populations
• Programmed GPS unit programmed for nematicide
  rate based on the nematode distribution map
• Equipment suitable for nematicide rate
  adjustment

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What Is The Link Between Nematodes And Fusarium
Wilt In Cotton?

• Fusarium is a soilborne fungus that causes cotton
  to wilt and die.
• Most cotton varieties have Fusarium wilt
  resistance thanks to efforts by breeders.
• However, when nematodes are present, they break
  this Fusarium wilt resistance.
• Thus, two problems result, nematode damage and
  Fusarium wilt in cotton.

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Cotton and Peanut Rotation

• Cotton is attacked by the southern root-knot and
  reniform nematodes.
• Peanut is affected by the peanut root-knot and
  lesion nematodes.
• This makes for a good rotation to reduce nematode
  problems in each crop.
• However, do not use the same crop two years in a
  row.
• Cotton, peanut, cotton, peanut are better
  rotations but must be supplemented with low
  nematicide rates.
• The best rotation is adding another crop in the
  sequence corn (sorghum), soybean (resistant),
  or perennial grass crops.

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Additional Information

• Visit the U.S. Cotton Nematode Research and
  Education Committee site at http//www.cotton.org
  /tech/pest/nematode