Nematode risk thresholds for soybean

 A = nematodes are not likely to cause crop damage
 B = borderline populations in which crop damage may occur if other factors stress the crop
 C = populations are likely to cause crop damage and a significant loss of yield

 Risk code based on nematodes/500cc soil (August 1 to November 20 of year before planting crop)

Nematode

A
(little or no risk)

B
(moderate risk)

C
(high risk)
Root knot

<50

50-170

>170
Cyst juveniles

<20

20-60

>60
Dagger

<100

100-300

>300
Sting

0

10-20

>20
Lesion

<100

100-300

>300
Ring

<200

200-700

>700
Stunt

<300

300-1000

>1000
Spiral

<1000

>1000

--
Stubby root

<90

>90

--
Lance

<300

300-500

>500
 

 pmphipps@vt.edu
  bkeeling@vt.edu