1. Management of the Reniform Nematode in Cotton
Kathy Lawrence, Associate Professor Plant Pathology
Stan Usery, Jarrod Jones, Amy Dismukes and Taylor Boozer, Graduate research assistants
Bill Gazaway, Dale Monks, Charlie Burmester, James Akridge, Don Moore, Yucheng Feng, Bob Goodman, Andy Price

2. Nematodes
Microscopic worm like animals that are parasites of plants and animals

3. Nematodes Plant Parasites Beneficial Nematodes Marine Nematodes
Animal Parasites

4. Plant-Parasitic Nematodes
All plant-parasitic nematodes possess a Stylet
A stylet is a protrusable mouth structure used to penetrate the cells of the plant.

5. Plant-Parasitic Nematodes
Are obligate parasites that require a living host on which to feed and complete their life cycle.

6. Shape of Plant-Parasitic Nematodes
Spiral Nematode

7. Plant-Parasitic Nematodes
300 to1000um long
15 to 35um wide
Transparent
Visible with a microscope

8. Plant-Parasitic Nematodes
Stems
Pinewood Nematode
Roots
Root-knot on Tomato
Leaves
White Tip on Rice
Seed
Seed Gall on Wheat

9. Nematode Soil Sample
Only true way to determine if nematodes are present

10. Nematode Soil Sample Divide the field into manageable blocks.
Sample in a zig-zag manner across each block.

11. Nematode Population Density Seasonal Fluctuations
Nematodes / pint soil

12. Nematodes Associated With Cotton
Root-knot Meloidogyne incognita
Reniform Rotylenchulus reniformis

13. Root-Knot Nematode Field Symptoms
Elliptical areas in the field with stunted growth.
Small to several acres in size.
Later in the season areas of excessive weed growth

14. Root-Knot Nematode Field Symptoms
Knots or galls on the roots.

15. Root-Knot Nematode
Each gall contains one or more adult root-knot females

16. Root-knot Nematode Second-stage juveniles (J2). Small - 425um long
Small delicate stylet but very damaging to the roots.
The infective stage for the nematode

17. Root-Knot Nematode Population Thresholds
Spring
10 J2 / 100cc soil.
Fall
J2 / 100cc soil.

18. Root-knot Nematode Meloidogyne incognita M. arenaria M. javanica
Race 1, 2, 3, & 4
M. arenaria
Race 1 & 2
M. javanica
M. hapla

19. Reniform Nematode Field symptoms
Uneven or up and down plant heights
Once established there are few to no symptoms.
Crop continues to produce lower yields each year.

20. Reniform Nematode on a Cotton Root
Reniform (kidney) in shape
Anterior part of body is embedded in the root with the posterior to the outside.

21. Reniform Nematode Root Symptoms
Difficult to see
Small egg masses covered with soil particles
Root necrosis

22. Gravid female
Male
Juvenile
Female

23. Reniform Nematode Vermiform female is the infective stage
Small - 600um in length
Sclerotized cephalic region

24. Reniform Nematode Population Thresholds

25. Plant-Parasitic Nematode Management
Resistant/Tolerant Varieties
Crop Rotations
Chemical Management

26. Resistant Varieties Root-knot - Cotton – ST 5599 (resistant/tolerant)
Soybean – resistance available
Reniform - Cotton - no resistance
Soybean - resistance available

27. Resistance and Tolerance
Resistance is the effect of the cotton host on nematode reproduction: a completely resistant plant allows no nematode reproduction.
Tolerance:
Tolerance is the amount of cotton host injury: a tolerant plant suffers little yield loss when heavily infected with nematodes.

28. Cotton cultivar Evaluation Reniform nematode
150cc of sterile soil
Inoculated 1000 R. reniformis.
60 days
Reniform were extracted combined gravity screening and sucrose centrifugal floatation.
Eggs extracted sodium hypochlorite.
Reproduction = Total reniform/initial number.

30. Cotton cultivar yield response to R. reniformis (tolerance).
Varieties planted with and without
a nematicide.
Determine R. reniformis numbers.
Yield
with and without the nematicide.

31. Field Trials Materials & Methods
Infested reniform nematode
Nematicides;
Temik + Vydate
Telone
Nematodes sampled at planting, mid-season, and harvest
12 varieties tested
4 reps
Seed cotton yields recorded

32. Limestone Co
-1.2; +7.5
+13.8; +2.1
+0.3; +19.4

33. Escambia Co., AL

34. 2004, Huxford, AL
Thanks to a tropical storm and hurricane Ivan yields were not recorded in 2002 or 2004

35. Cotton cultivars
High yielding cultivars provide the most economic benefit currently –
Tolerance has varied by location and year.

36. Crop Rotation Root-knot - resistant soybeans
Reniform - resistant soybeans
- corn, grain sorghum, peanut

37. Soybean Variety Evaluations Reniform Nematode
Mississippi State University
Screened varieties Resistant
MG –IV, V, VI
University of Arkansas
Screened varieties Resistant
MG –III + IV
Auburn University
Screened varieties Resistant
MG –IV - VIII
(8 MR)

38. Average Seed Cotton Yield One Year Rotation- W. Gazaway Escambia Co. AL

39. 50+

40. Chemical Management

41. Nematicide Tests - 2005 Small Plots - Nematicides - Telone II Vapam
Temik 15G
Vydate C-LV
Experimental Temik
Seed Treatments Avicta complete pack
Gaucho L1489A FS EC
Gaucho exp600003BFS SC
Biological N-Hibit

42. Material and Methods Small Plot Tests - 2005
Variety ST 5599 BG/RR
DP 444 BG/RR
Exp. Design Randomized complete block
5 -6 replications
Plot Design row plots
25’ long & ” row spacing
Planting Date April 29 and May 1, 2005
Nematodes Sampled Monthly
Extraction Technique Gravity screening and centrifugal flotation
Harvest Date Oct. 5, 2005
KSL ‘06

43. Avicta Complete Pak, Temik 15 G and Vydate C-LV 2005 Test 108A DP 444 BG/RR
Treatment Rate Application
1. Dynasty+Cruiser
2. AvictaCP mg/seed Seed treatment
3. Dynasty+Temik 15G 5.0 lb In-furrow
4. AvictaCP+Temik 15G 0.15mg+5.0 lb ST + IF
5. Dynasty+Temik +Temik 15G lb ST + IF + SD
6. AvictaCP+Vydate mg+17oz ST+6LS
7. AvictaCP+Temik+Vydate 0.15mg+5lb+17oz ST+IF+6LS
8. Dynasty+Cruiser+Vydate 0.15mg+17oz ST+6TL
KSL ‘06

44. Vydate
KSL 06

45. LSD 657
KSL 06

46. KSL 06

47. Vydate
KSL 06

48. LSD 343
KSL 06

49. KSL 06

50. Avicta Complete Pak 2005 Test 104A DP 444 BG/RR ST5599BGRR
Treatment Rate
1. Dynasty + Cruiser ---
2. AvictaCP mga/seed
3. Dynasty + Temik 15G 5.0 lb
4. Dynasty + Temik 15G 7.0 lb
5. Allegiance + Baytan +
Thiram + Temik 15G 5.0 lb
GWL ‘06

51. KSL 06

52. LSD 458
KSL 06

53. LSD 458
KSL 06

54. KSL 06

55. KSL 06

56. LSD 786
KSL 06

57. KSL 06

58. LSD 302
KSL 06

59. KSL 06

60. Effect of Bayer Experimentals Temik Formulations on Reniform in Belle Mina, 2005

61. KSL 06

62. LSD 451
KSL 06

63. Effect of Telone II, Vapam and Temik 15G on Cotton Yields in Belle Mina, 2004
KSL 06

64. Plant-Parasitic Nematode Management
Resistant/Tolerant Varieties
Crop Rotations
Chemical Management

67. Root-knot Nematode M. i. R1 - + M. i. R2 M. i. R3 M. i. R4 M. a. R1
Cotton
Tobacco
Pepper
Watermelon
Peanut
Tomato
M. i. R1 - +
M. i. R2
M. i. R3
M. i. R4
M. a. R1
M. a. R2
M. j.
M. h.

68. Chemical Management Chemical Application Cost / Acre Aldicarb Temik
In furrow $
1,3-dichloropropene
Telone II
Fumigate $
Sodium methyldithiocarb
Vapam $
Oxamyl
Vydate
Foliar Spray $
Avermectin
Avicta
Seed $
The 4 most commonly used chemical control methods in Alabama are…
At a cost of … per acre

69. Seed Cotton Yield Loss by At-Plant Reniform Nematode Population Densities

70. KSL 06

71. Economic Benefit Chemical Yield Cost / A Gross/A Temik 5 – 7 lb/A 1259$
$612
Avicta mg/seed
1389 $
$674
Dynsasty + Cruiser
1314
$657
The 4 most commonly used chemical control methods in Alabama are…
At a cost of … per acre
KSL 06

72. KSL 06

73. LSD 235
KSL 06