Zane Grabau
@ufcropnematodes.bsky.social
Associate Professor in Nematology, University of Florida.
Plant-parasitic nematode management in North Florida field crops.
Cotton, peanut, corn, potato, carrots, and more.
Plant-parasitic nematode management in North Florida field crops.
Cotton, peanut, corn, potato, carrots, and more.
Harvested our last summer trial of the year yesterday. This was a cotton trial at NFREC-Quincy testing in-furrow nematicides and resistant cultivars against reniform nematode.
November 19, 2025 at 5:16 PM
Harvested our last summer trial of the year yesterday. This was a cotton trial at NFREC-Quincy testing in-furrow nematicides and resistant cultivars against reniform nematode.
Our carrot nematicide trial at Live Oak at 8 weeks after planting. Obvious differences in plant stand and foliage among treatments.
Root-knot nematode is the target Symptoms are likely from this nematode as the untreated looks poor and there are root symptoms (next post).
Root-knot nematode is the target Symptoms are likely from this nematode as the untreated looks poor and there are root symptoms (next post).
November 14, 2025 at 1:02 PM
Our carrot nematicide trial at Live Oak at 8 weeks after planting. Obvious differences in plant stand and foliage among treatments.
Root-knot nematode is the target Symptoms are likely from this nematode as the untreated looks poor and there are root symptoms (next post).
Root-knot nematode is the target Symptoms are likely from this nematode as the untreated looks poor and there are root symptoms (next post).
Earlier this week, I enjoyed learning from colleagues as part of the joint meeting of southern and western USDA multi-state nematology projects.
Dr. Oyetunde talked about a couple projects from our lab.
Dr. Oyetunde talked about a couple projects from our lab.
November 13, 2025 at 1:02 PM
Earlier this week, I enjoyed learning from colleagues as part of the joint meeting of southern and western USDA multi-state nematology projects.
Dr. Oyetunde talked about a couple projects from our lab.
Dr. Oyetunde talked about a couple projects from our lab.
Carrot nematicide trial at Citra. Parallel to our Live Oak trial, but planted a week later.
We are also seeing differences in plot growth among plots in this trial. Root-knot nematode is the target.
We are also seeing differences in plot growth among plots in this trial. Root-knot nematode is the target.
November 4, 2025 at 1:10 PM
Carrot nematicide trial at Citra. Parallel to our Live Oak trial, but planted a week later.
We are also seeing differences in plot growth among plots in this trial. Root-knot nematode is the target.
We are also seeing differences in plot growth among plots in this trial. Root-knot nematode is the target.
Carrot nematicide trial @nfrec_sv at 6 weeks after planting. Carrot roots are starting to form and differences in plant stand and vigor among treatments are apparent. Testing for management of root-knot nematode.
November 3, 2025 at 9:43 AM
Carrot nematicide trial @nfrec_sv at 6 weeks after planting. Carrot roots are starting to form and differences in plant stand and vigor among treatments are apparent. Testing for management of root-knot nematode.
Severe infestation of peanut root-knot nematode in our peanut trial @ufifasnfrec. Symptoms on vines as well as galling on pods and roots.
October 18, 2025 at 1:37 PM
Severe infestation of peanut root-knot nematode in our peanut trial @ufifasnfrec. Symptoms on vines as well as galling on pods and roots.
Carrot trial at Live Oak testing nematicides for management of root-knot nematode. At 4 weeks after planting, there are differences in plant stand and vigor amoung treatments.
Likely due to nematode management as the untreated is poor. Upcoming nematode assessments will inform.
Likely due to nematode management as the untreated is poor. Upcoming nematode assessments will inform.
October 17, 2025 at 1:11 PM
Carrot trial at Live Oak testing nematicides for management of root-knot nematode. At 4 weeks after planting, there are differences in plant stand and vigor amoung treatments.
Likely due to nematode management as the untreated is poor. Upcoming nematode assessments will inform.
Likely due to nematode management as the untreated is poor. Upcoming nematode assessments will inform.
We are comparing cotton cultivars resistant and susceptible to reniform+root-knot nematode within the long-term sod-based rotation @ufifasnfrec. Post-harvest, resistant is clearly taller than susceptible at this site with reniform nematode.
October 14, 2025 at 8:49 AM
We are comparing cotton cultivars resistant and susceptible to reniform+root-knot nematode within the long-term sod-based rotation @ufifasnfrec. Post-harvest, resistant is clearly taller than susceptible at this site with reniform nematode.
Another day another peanut trial harvest. We dug and harvested our peanut trial at Citra in the same day due to rain in the forecast. Commercially, there are downsides like increased drying cost & more pod loss/damage, but less important for our situation.
October 2, 2025 at 12:10 PM
Another day another peanut trial harvest. We dug and harvested our peanut trial at Citra in the same day due to rain in the forecast. Commercially, there are downsides like increased drying cost & more pod loss/damage, but less important for our situation.
12 days after planting for our carrot nematicide trial @nfrec_sv. Even up close, they are still at the "squint to see them" stage.
September 29, 2025 at 11:21 AM
12 days after planting for our carrot nematicide trial @nfrec_sv. Even up close, they are still at the "squint to see them" stage.
Yesterday we dug out first peanut trial of the year at NFREC-SV. Testing efficacy of some conventional and biological nematicides for management of peanut root-knot nematode.
September 27, 2025 at 9:30 AM
Yesterday we dug out first peanut trial of the year at NFREC-SV. Testing efficacy of some conventional and biological nematicides for management of peanut root-knot nematode.
Yesterday we planted the second location of our carrot nematicide trial. We are testing various conventional and biological nematicides for management of root-knot nematode.
We applied some nematicides by watering can to mimick application through overhead irrigation.
We applied some nematicides by watering can to mimick application through overhead irrigation.
September 25, 2025 at 12:12 PM
Yesterday we planted the second location of our carrot nematicide trial. We are testing various conventional and biological nematicides for management of root-knot nematode.
We applied some nematicides by watering can to mimick application through overhead irrigation.
We applied some nematicides by watering can to mimick application through overhead irrigation.
Carrot planting @nfrec_sv. We are testing nematicides for root-knot nematode control. After planting, we applied some liquid nematicides by watering can to mimick application through overhead irrigation.
September 15, 2025 at 8:20 PM
Carrot planting @nfrec_sv. We are testing nematicides for root-knot nematode control. After planting, we applied some liquid nematicides by watering can to mimick application through overhead irrigation.
Symptoms of root-knot nematode infection on peanut from one of our trials. Symptoms often come on late, so now is a good time to be checking to plan management for future years.
September 10, 2025 at 12:26 PM
Symptoms of root-knot nematode infection on peanut from one of our trials. Symptoms often come on late, so now is a good time to be checking to plan management for future years.
Collected root samples to assess peanut root-knot nematode infestation on various peanut cultivars in this trial at Citra.
7 weeks after planting. Pods are forming and there are subtle differences amoung cultivar canopies.
7 weeks after planting. Pods are forming and there are subtle differences amoung cultivar canopies.
July 1, 2025 at 6:05 PM
Collected root samples to assess peanut root-knot nematode infestation on various peanut cultivars in this trial at Citra.
7 weeks after planting. Pods are forming and there are subtle differences amoung cultivar canopies.
7 weeks after planting. Pods are forming and there are subtle differences amoung cultivar canopies.
Foliar damage and root galling from root-knot nematode on soybean at NFREC-SV. Intent is to increase root-knot nematode populations before a late summer carrot trial.
June 25, 2025 at 1:05 PM
Foliar damage and root galling from root-knot nematode on soybean at NFREC-SV. Intent is to increase root-knot nematode populations before a late summer carrot trial.
7 weeks after planting for our peanut trial @nfrec_sv. We are testing in-furrow nematicides and a couple cultivars for management of peanut root-knot nematode.
Pegs and pods are forming and seeing differences in canopy size/stand amoung plots.
Pegs and pods are forming and seeing differences in canopy size/stand amoung plots.
June 24, 2025 at 12:51 PM
7 weeks after planting for our peanut trial @nfrec_sv. We are testing in-furrow nematicides and a couple cultivars for management of peanut root-knot nematode.
Pegs and pods are forming and seeing differences in canopy size/stand amoung plots.
Pegs and pods are forming and seeing differences in canopy size/stand amoung plots.
Checked cotton stands in our reniform nematode trial @ufifasnfrec. Treatments are combinations of various cultivars with or without an in-furrow nematicide.
We did see differences amoung cultivars, likely due to vigor of particular cultivars/seed lots.
We did see differences amoung cultivars, likely due to vigor of particular cultivars/seed lots.
June 20, 2025 at 1:18 PM
Checked cotton stands in our reniform nematode trial @ufifasnfrec. Treatments are combinations of various cultivars with or without an in-furrow nematicide.
We did see differences amoung cultivars, likely due to vigor of particular cultivars/seed lots.
We did see differences amoung cultivars, likely due to vigor of particular cultivars/seed lots.
As part of our in-house peanut extension training, we toured the small sheller at NFREC-Marianna and a commercial sheller.
Learned a lot about how shelling factors influence production.
Learned a lot about how shelling factors influence production.
June 18, 2025 at 1:42 PM
As part of our in-house peanut extension training, we toured the small sheller at NFREC-Marianna and a commercial sheller.
Learned a lot about how shelling factors influence production.
Learned a lot about how shelling factors influence production.
We pulled mid season soil and root samples from our cotton trial @nfrec_sv to test efficacy of conventional in-furrow nematicides at managing guava root-knot nematode.
There are small galls on the root system. The size and number of galls increases with time and varies by crop.
There are small galls on the root system. The size and number of galls increases with time and varies by crop.
June 17, 2025 at 10:43 AM
We pulled mid season soil and root samples from our cotton trial @nfrec_sv to test efficacy of conventional in-furrow nematicides at managing guava root-knot nematode.
There are small galls on the root system. The size and number of galls increases with time and varies by crop.
There are small galls on the root system. The size and number of galls increases with time and varies by crop.
Comparing reniform nematode resistant and susceptible cultivars within long-term crop sequences in trial @ufifasnfrec.
At 6 weeks after planting, canopy size is much bigger in resistant than susceptible cultivar. Also differences amoung crop sequences.
At 6 weeks after planting, canopy size is much bigger in resistant than susceptible cultivar. Also differences amoung crop sequences.
June 4, 2025 at 1:04 PM
Comparing reniform nematode resistant and susceptible cultivars within long-term crop sequences in trial @ufifasnfrec.
At 6 weeks after planting, canopy size is much bigger in resistant than susceptible cultivar. Also differences amoung crop sequences.
At 6 weeks after planting, canopy size is much bigger in resistant than susceptible cultivar. Also differences amoung crop sequences.
Yesterday we planted our final summer trial of the year, a cotton trial @ufifasnfrec. We are testing cultivars with combinations of thryvon and multi-nematode-resistance as well as in-furrow fluopyram nematicide for reniform nematode management.
June 3, 2025 at 4:40 PM
Yesterday we planted our final summer trial of the year, a cotton trial @ufifasnfrec. We are testing cultivars with combinations of thryvon and multi-nematode-resistance as well as in-furrow fluopyram nematicide for reniform nematode management.
One of our soybean fields has sting nematode and is showing typical symptoms:
1. Patchy aboveground stunting
2. Stunted root system with stubby, proliferating lateral roots
Even with low counts, damage can be severe.
1. Patchy aboveground stunting
2. Stunted root system with stubby, proliferating lateral roots
Even with low counts, damage can be severe.
May 28, 2025 at 7:35 PM
One of our soybean fields has sting nematode and is showing typical symptoms:
1. Patchy aboveground stunting
2. Stunted root system with stubby, proliferating lateral roots
Even with low counts, damage can be severe.
1. Patchy aboveground stunting
2. Stunted root system with stubby, proliferating lateral roots
Even with low counts, damage can be severe.
Testing peanut lines for resistance to peanut root-knot nematode in this field trial at Citra. At two weeks after planting, emergence generally looks good.
May 27, 2025 at 4:24 PM
Testing peanut lines for resistance to peanut root-knot nematode in this field trial at Citra. At two weeks after planting, emergence generally looks good.
Extension agent brought in these stunted, frazzled young peanut roots compared with healthy roots. He was thinking herbicide damage, but wanted to double-check for plant-parasitic nematodes.
Symptoms look like sting nematode. He brought soil samples and will extract nematodes to diagnose
Symptoms look like sting nematode. He brought soil samples and will extract nematodes to diagnose
May 22, 2025 at 8:32 AM
Extension agent brought in these stunted, frazzled young peanut roots compared with healthy roots. He was thinking herbicide damage, but wanted to double-check for plant-parasitic nematodes.
Symptoms look like sting nematode. He brought soil samples and will extract nematodes to diagnose
Symptoms look like sting nematode. He brought soil samples and will extract nematodes to diagnose