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Cotton Nematode Management Jimmy R. Rich and Charles Overstreet.

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Presentation on theme: "Cotton Nematode Management Jimmy R. Rich and Charles Overstreet."— Presentation transcript:

1 Cotton Nematode Management Jimmy R. Rich and Charles Overstreet

2 Nematode Facts

3 Nematodes are Highly Underrated 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.

4 Nematode Anatomy

5 Nematodes in Roots A. A. Triccoli

6 Plant-Parasitic Nematode Stylet (Spear)

7 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!!)

8 Nematodes in Cotton J.R. Rich

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

10 Distribution of root-knot nematode

11 Distribution of reniform nematode

12 Plant and Root Damage Symptoms

13  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 Foliar Damage Symptoms Water and Nutrient Stress

14 Cotton Field Abandoned Due to Nematode Damage M. Donahoe

15 Young Cotton Stunted by Nematodes B. Gazaway

16 Nematode Damage Following Soil Type Change B. Gazaway

17 Damage on Maturing Cotton J.R. Rich

18 Purpling of Cotton Leaves by Reniform Nematodes J.R. Rich

19 Plant Root Damage  Stunted roots  Fewer feeder roots  Root galling and swelling  Root cell death or cell malfunction  Openings for disease organisms

20 Root-Knot Nematode Galling on Roots, Not Very Apparent J.R. Rich

21 Female Root-Knot with Eggs, Root is the Size of a Pinhead R.S. Hussey

22 Reniform Nematode Females Partially inside Roots, No Root Galling Females teased out and laid on top of root C. Overstreet

23 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

24 Comparison of Nematode Damage Symptoms on Cotton Root-KnotReniform Galled roots No galling Little leaf discoloring Leaf purpling Irregular patches General decline Patches obvious Less obvious Sands, loams Loams, clays Lower numbers Higher numbers

25 Nematode Problem Assessment Nematode Problem Assessment

26 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

27 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

28 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

29 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

30 Tools for taking nematode soil samples Choice of sampling tools Plastic bag Permanent ink marker Bucket

31 Ten Acre Sampling Patterns (Take 15 To 20 Cores) Centered GridIntersected Grid Zig ZagRandom

32 Managing Cotton Nematodes

33 Management Methods  NEMATICIDES   Rotation  Sanitation  Resistance

34 Cotton Nematicides  Temik 15G - Bayer CropScience  Telone II - Dow AgroSciences  Avicta Complete Pak- Syngenta  K-pam or Vapam- Amvac  Vydate~ Dupont

35 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)

36 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

37  Sold only as a seed treatment  Combination of fungicide, insecticide, and nematicide  Chemicals are present on the seed at the time of planting Avicta Comptete Pak Product Information

38 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 -

39 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

40 Farmer Field Demonstration No Treatment ↓ Telone II ↓ M. Donahoe

41 Management Methods  Nematicides  ROTATION   Sanitation  Resistance

42 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.

43 Management Methods  Nematicides  Rotation  SANITATION   Resistance

44 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

45 Nematode Weed Hosts in Bahiagrass Pasture J.R. Rich

46 Frequently Asked Questions J.R. Rich

47 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

48 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.

49 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.

50 Additional Information Visit the U.S. Cotton Nematode Research and Education Committee site at: Visit the U.S. Cotton Nematode Research and Education Committee site at:

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