One shot at nematode control: Why timing matters for farmers
As spring planting gets closer, farmers in Gadsden County are preparing for another
growing season. While most attention is on seed choices and fertilizer plans, there’s a
hidden threat beneath the soil that can quietly rob yields…nematodes. These tiny
roundworms attack plant roots, making it harder for crops to take up water and
nutrients. The result? Stunted plants, yellow leaves, and disappointing harvests.
Experts say nematodes are one of the toughest pests to manage because you can’t see
them until the damage is done. By the time symptoms show up in the field, it’s too late
to stop them. That’s why Dr. Bob Kemerait, a respected plant pathologist with UGA
Extension in Tifton, warns farmers: “You get one chance to make nematode control with
nematicides in the furrow.” In other words, the best, and often only, time to fight
nematodes is at planting, before the furrow is closed.
Once the seed is covered and the soil is packed down, nearly all options for nematode
control are gone. From that point on, the crop is on its own. If nematodes are present,
they’ll attack young roots early, reducing the return on every other input, fertilizer,
irrigation, and even fungicides, because the plant can’t grow properly.
So, what can farmers do? The first step is knowing what’s in your soil. UF/IFAS
Extension recommends soil sampling in the fall or winter to check nematode levels
before planting. The UF Nematode Assay Lab in Gainesville can identify species like
root-knot, reniform, and sting nematodes, which are common in North Florida. Each
species affects crops differently, so accurate identification is key to choosing the right
management plan. The Gadsden County Extension Office can assist with soil collection
for nematode assays.
If nematodes are a problem, in-furrow nematicides can make a big difference. UF/IFAS
research shows that products like fluopyram (Velum Total) and granular nematicides
such as aldicarb (AgLogic 15GG) can protect roots during the critical early weeks of
growth. These treatments put the active ingredient right where roots and nematodes
meet, giving the crop a fighting chance. But timing is everything, if you miss that window
at planting, there’s no second shot.
It’s important to note that many nematicides are restricted-use chemicals and require a
valid Florida pesticide applicator license through FDACS. Some products, like aldicarb
(AgLogic 15GG), require additional permitting and regulations beyond the normal
restricted-use pesticide rules. For more information on aldicarb permitting, Dr. Zane
Grabau, UF/IFAS Extension Nematologist, has an article on the UF/IFAS EDIS website
titled How to Obtain an Aldicarb Application Permit for Florida Cotton or Peanut
(Publication Number ENY2095).
Chemical control isn’t the only tool. UF/IFAS also recommends crop rotation with non-
host crops, planting resistant varieties, and using cover crops to reduce nematode
populations over time. These cultural practices work best when combined with
nematicides at planting for fields with high nematode pressure.
Farmers should start planning now. Review your field history, consider pest pressure,
and contact the Gadsden County Extension Office for sampling and treatment options.
Nematodes may be small, but their impact is big. Missing that one chance at planting
can cost you yield and profit all season long. For more information, contact the Gadsden
County Extension Office or visit UF/IFAS online at https://edis.ifas.ufl.edu. With the right
plan and timely action, you can protect your crop and make 2026 a productive year.
Robbie Jones is the Agriculture and Natural Resources Agent/County Extension Director for UF/IFAS Extension Gadsden County.
