This work is licensed under the Creative Commons Attribution 4.0 International License.
Figure 1:
Map of Wisconsin showing counties colored according to their representation (number of bienniums) in the survey data: green = seven; dark blue = six; light blue = five; purple = four; orange = three; yellow = two; red = one; white = not included. The star symbol indicates counties with soybean planted on more than 15,000 ha in 2021. Nine agricultural districts are outlined in bold.
Prevalence of pest nematodes in samples shown by the crop sampled.
crop
n
Pratylenchus
Spiral
Xiphinema
Hoplolaimus
stunt
stubby-root
ring
Longidorus
cyst
soybean
3309
84
73
31
3
16
5
2
0
29
corn
2188
84
67*
37*
6*
18*
5
2
1
20*
wheat
75
89
83
23
5
31*
5
3
1
27
alfalfa
32
81
69
41
3
44*
0
6
0
3*
vegetables
38
76
58
8
0
37*
8
3
0
21
Chi Square
4
27
37
31
45
3
3
15
64
p
0.48
<0.0001
<0.0001
0.0001
<0.0001
0.64
0.53
0.03
<0.0001
Program information and prevalence of cyst nematodes for all samples and every farm that was assayed for cyst nematodes.
Biennium
Number of counties sampled
Number of samples
Number of farms sampleda
% samples positive for cyst nematodes
% farms positive for cyst nematodesb
Odds Ratio current biennium vs 1998–1999
1998 – 1999
42
659
427
16
16
2010 – 2011
38
379
150
22*
23*
1.84*
2012 – 2013
51
1121
377
22
31*(p = 0.06)
2.59***
2014 – 2015
54
1268
413
22
30
2.63***
2016 – 2017
49
1132
299
26*
40**
3.87***
2018 – 2019
49
1588
334
29*
43
4.86***
2020 – 2021
51
1862
320
27
39
3.75***
Prevalence of all pest nematode from 2012 to 2021 at the sample and farm scale.
Pest nematodesa
samples (6971)
farms (n = 1743)
Odds ratioc
% positive
% positive
(p < 0.0001)
Pratylenchus spp.
84
92
21.27
Spiral nematodes
70
78
6.33
Xiphinema spp.
33
46
1.52
Cyst nematodes
26
36
reference
Stunt nematodes
18
28
0.68
Stubby Root nematodes
6
9
0.17
Hoplolaimus spp.
5
7
0.13
Ring nematodes
3
6
0.12
Longidorus spp.
1
2
0.03
Chi Square statisticb
6,805
26,257
P
< 0.0001
< 0.0001
Population densities of Pratylenchus spp. or spiral nematodes and cyst-forming species in the presence (+) and absence (−) of each other in samples collected from soybean fields in Wisconsin from 2012 to 2021.
Comparison
Samples
Nematodes per 100 cm3 soila
Kruskal Wallis
n
Mean (Maximum)
Chi Square
p
Pratylenchus / − Cyst
2349
121 (4960)
Pratylenchus / + Cyst
960
71 (1508)
90.63
< 0.0001
Cyst / − Pratylenchus
518
1144 (44364)
Cyst / + Pratylenchus
2791
452 (49494)
30.41
< 0.0001
Pratylenchus species identified from 100 soil samples submitted to a nematode testing program in Wisconsin.