Yield-Robbing Parasites Root-knot nematodes are still the primary microscopic pest in peanut, but both sting and lesion nematodes can be found in some areas. By Amanda Huber
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icroscopic, voracious, deceptive, invasive, damaging. There are many ways to describe nematodes. In peanut, the most common is the rootknot nematode, although both sting and lesion
can be found. Because nematodes are microscopic and symptoms are often not recognized, they are frequently undermanaged. Producers are losing yield to this destructive pest and should take steps to ensure adequate control.
Start With Crop Rotation For nematode management, there are three primary practices: crop rotation, resistant cultivars and nematicide applications. Rotation with a crop that is not a host for root-knot nematode is always the starting place in management. This is always considered an effective management tool. Next would be resistant cultivars, and University of Florida Extension nematologist Zane Grabau says in peanut, there are several resistant cultivars available now. “TifNV-HighO/L was released by the U.S. Department of Agriculture Agricultural Research Service in Tifton, Georgia, a few years ago. This variety has the near immunity to nematodes as does Tifguard with the high-oleic oil trait. It also has resistance to tomato spotted wilt virus and is similar in plant and seed characteristics to Tifguard, which is still available to plant.” Another option, Georgia-14N, was released several years ago by the Georgia Agricultural Experiment Station and developed at the University of Georgia Coastal Plain Experiment Station. It is a small-seeded, runner-type peanut variety that is resistant
To Manage Nematodes: ■ ■ ■
Crop rotation Variety selection Nematicides: ◽ Telone II (4.5-9 gal/A) ◽ AgLogic (7 lbs/A in furrow) ◽ Velum Total (18 fl oz/A in furrow) ◽ Velum (6.5 to 6.84 fl oz/A in furrow) ◽ Propulse (13.6 fl oz/A pegging time) ◽ Vydate CLV (for application information, see label) ◽ Return XL (for application information, see label)
to spotted wilt and root-knot nematodes. It also has high-oleic oil chemistry. What To Do In Fields With Heavy Pressure “TifNV-HighO/L, Tifguard and Georgia 14N all have the same parentage and very strong resistance to root-knot nematodes,” Grabau says. “Plant resistant cultivars in fields with heavy root-knot nematode pressure, and they are going to perform about as well as they would in a field without pressure. “Some data we’ve seen over the last couple of years shows that in heavy root-knot nematode fields, you are better off going with a resistant cultivar rather than a nematicide with a susceptible cultivar. “Under heavy pressure, these are good options for preserving yield. If you have sting or lesion nematodes, the resistant cultivars do not work against these species,” he says.
In the Southeast, nematodes found in peanut are often assumed to be root-knot nematodes (Meloidogyne arenaria and Meloidogyne javanica). However, Florida peanut growers may also find sting nematode (Belonolaimus longicaudatus) to be the primary problem in their field.
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THE PEANUT GROWER • APRIL 2021
PEANUTGROWER.COM
