1. Cotton Nematode Management Jimmy R. Rich and Mike Donahoe

2. Nematode Facts 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 greater than 90% of Florida cotton

4. Nematode Anatomy

5. Nematodes in Roots

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  Female produces 300-400 eggs  Over one season - 1 female = 8 billion and more nematodes (hence the problem!!)

8. Nematodes in Florida Cotton Nematodes in Florida Cotton

9. Major Florida Cotton Nematode Pests In order of importance: Southern Root-Knot Nematode, Meloidogyne incognita Southern Root-Knot Nematode, Meloidogyne incognita Reniform Nematode Reniform Nematode Rotylenchulus reniformis Rotylenchulus reniformis Sting Nematode Sting Nematode Belonolaimus longicaudatus Belonolaimus longicaudatus

10. North Florida Cotton Nematode Survey 2004  A survey was conducted in three counties: Santa Rosa, Escambia, and Okaloosa  Cotton fields randomly chosen by agents  Survey included 61 soil samples in about 35 fields  Sample represented 10-12 soil cores taken in 15-20 acres each  Sample represented 10-12 soil cores taken in 15-20 acres each

11. Cotton Nematode Survey 2004 Nematode Sample content (%) Root-Knot48 Reniform42 None10

12. Damaging Nematode Levels for Following Year Cotton County YesLikelyNo --------- Sample, % --------- Okaloosa452727 Escambia462925 Santa Rosa 58358 Average503020

13. Plant and Root Damage Symptoms Plant and Root Damage Symptoms

14.  Premature wilting in spots on plant or field ie 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

15. Cotton Field Abandoned Due to Nematode Damage

16. Young Cotton Stunted by Nematodes

17. Nematode Damage Following Soil Type Change

18. Damage on Maturing Cotton

19. Purpling of Cotton Leaves by Reniform Nematodes

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

21. Root-Knot Nematode Galling on Roots, Not Very Apparent

22. Female Root-Knot with Eggs, Root is the Size of a Pinhead

23. Reniform Nematode Females Always Outside Root, No Root Galling

24. 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

25. 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

26. Nematode Problem Assessment Nematode Problem Assessment

27. 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

28. 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

29. 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

30. 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

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

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

33. Managing Cotton Nematodes

34. Management Methods  NEMATICIDES   Rotation  Sanitation  Resistance

35. Cotton Nematicides  Temik 15G - Bayer CropScience  Telone II - Dow AgroSciences  Nemacur - Bayer CropScience  (cancellation notice for 2007)

36. 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)

37. 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

38. Telone and Temik Are Restricted Use Pesticides  Reminder - both products have specific use restrictions!!  Temik has special reporting and use requirements in Florida  Temik 15G forms and other requirements can be found at FDACS Web Site - http://www.safepesticideuse.com

39. Florida Cotton Nematicide Recommendations  Temik 15G (In Furrow)  Root-knot nematode – 7 lb./A  Reniform nematode – 5 lb./A  Telone II (In Row, Single Chisel)  Root-knot nematode – 4-5 gal./A  Reniform nematode – 3 gal./A

40. Comparative Cotton Yields Recommended Rates  Telone II (in-row application)  Root-knot – 1 gal = Minimum 50 lb. lint/A  Reniform – 1 gal = Minimum 35 lb. lint/A  Temik 15G (at-planting application)  Root-knot & reniform – 1 lb. formulation  = 8-10 lb. lint/A (variable)

41. Farmer Field Demonstration No Treatment Telone II

42. ‘Other’ Nematicides  Mocap – Bayer CropScience  Vydate - DuPont  Counter - BASF  Furadan - FMC  Vapam – AmVac Corporation  Chlor-O-Pic - Hendrix and Dial

43. Management Methods  Nematicides  ROTATION   Sanitation  Resistance

44. 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.  Root-knot nematodes have a wide host range (see Cotton Management Guide for host list).

45. Management Methods  Nematicides  Rotation  SANITATION   Resistance

46. Sanitation Notes  Control weeds, many are nematode hosts including Morningglory, Florida Pusley, Tropical Spiderwort, Nut Sedge, etc.  Prevent crop regrowth in peanut and cotton to stop nematode population increase in the fall  Perennial grass rotation (bahiagrass) does not work with weed hosts present

47. Nematode Weed Hosts in Bahiagrass Pasture

48. Frequently Asked Questions

49. Is GPS/GIS Variable Rate Nematicide Application Feasible? This is ‘doable’ technology  Is it economical?  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

50. 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.

51. Cotton and Peanut Rotation  Cotton is attached 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.

52. Additional Information  Visit the UF/IFAS EDIS Web Site - http://edis.ifas.ufl.edu http://edis.ifas.ufl.edu  Search for ‘Cotton Nematodes’