JUSTIFICATION Plant-parasitic nematodes (PPN) cause subtle to severe losses in
Virginia soybeans. In some cases, PPN predispose plants to other diseases and
cause even more losses such as with SDS (sudden death syndrome). Although
less widespread than SCN (soybean cyst nematode), root-knot nematode (RKN)
can cause severe losses, even death of plants. Strategies used to manage these
PPNs are crop rotation, resistant varieties and nematicides. Of these, use of
resistant varieties is more effective and efficient when available. However, most
soybean varieties have R3 resistance to SCN derived from PI 88788, which may
be a problem as race-shifts in SCN populations have been observed in fields
continually planted to soybeans with the same source of SCN resistance. To
combat this the obvious tactic would be to rotate in soybeans with different
sources of resistance such as PI 548402 (Peking) a.k.a R1, R3. The problem with
that is that group 4 soybeans with R1, R3 resistance is almost non-existent, with
only a handful of group 5s (and to a lesser degree group 6s) currently available.
The same can be said for RKN resistance availability, although a few late group 4
varieties have become recently marketed. Therefore, there is a need to assess the
available nematode-resistant lines as well as monitor SCN and RKN field
populations for race shifts and RKN, respectively. Nematicide seed treatments
such as ILeVO and Saltro should provide some benefits in reducing losses to
nematodes, but recent trials have shown do they not provide a positive yield
increase, and in some cases, reduce yield compared to seed not treated with
these products. In addition, Velum has recently been labeled as an in-furrow
nematicide treatment on soybeans. There is little to no data on soybeans to
support the use of Velum applied as an at-plant, in-furrow treatment on
soybeans. The effect of planting date on nematicide seed treatment
performance, the effect of Velum as an in-furrow nematicide on soybeans need
to be investigated to provide the most sustainable nematode management
practices in Virginia soybeans. HG-typing fields grown to soybeans will aid
growers in decision-making regarding nematode resistant varieties.

1) Detect race shifts in SCN in Virginia soybean fields through HG-typing.
2) Evaluate the performance of ILeVO and Saltro across several planting dates in
a field infested with SCN.
3) Determine the utility of Velum as an in-furrow nematicide on soybean in
Virginia.

1) Utility of nematicide seed treatments will be determined according to planting
date.
2) Potential yield loss of seed treatment nematicides will be documented.
3) Benefits of Velum applied in-furrow to control SCN will be documented.
4) HG-types of SCN-infested fields will be determined and shared with growers
for more informed decisionmaking regarding variety selection or variety/crop rotations to account for SCN
race shifts.