Troup extension agent: Nasty critters the sequel — Nematodes

Published 12:00 am Friday, July 8, 2016

Some of the nastiest critters on planet earth are the ones we can’t see.

Many of us struggle with our gardens, lawns and ornamentals. We try to do everything right and somehow, we don’t get the results that we want.

Prior to the development of microscope technology, we had no idea that there were microscopic creatures in the soil that sting the roots of plants and cause quite a bit of damage. These small, microscopic round worms are called nematodes.

They can have large effect on the growth and success of many crops. There is just not one kind but many.

The root-knot nematode can be particularly troublesome to home gardeners. They feed on root cells with needle-like mouth parts called stylets. This injures the root system to such an extent that the plants can’t properly absorb water and nutrients.

One female root-knot nematode can lay as many as 500 eggs at a time. Damage results from sheer numbers of nematodes feeding.

Symptoms of this damage can be seen both above and below ground. These critters prefer sandy soils but are widespread throughout Georgia.

Root-knot nematodes can be confirmed only by examining the roots or sending them to the nematode testing lab at UGA. Look for the plants that wilt easily, look like they have a nutrient deficiency or just not doing as well as the other plants. The cost for testing the plants at UGA is $12 plus shipping.

Physically pull the plants up or dig them up to examine the roots. Both large and small roots will have many knots or galls.

The root system may be shallow or stunted from the damage. The damaged roots may have also severe rotting.

Don’t confuse the galls with the nitrogen-fixing nodules on legumes such as beans. These nodules will be on the side of the roots, generally uniform in size and pink on the inside.

If you determined that nematodes are present, what is the best course of action? The first step would be to plant resistant varieties.

The seed or plant labels will indicate which are resistant to nematodes. Check out our extension bulletins as well. Keeping the plants watered, fertilized and healthy as possible will help check some of the effects of the nematodes.

If you have a contaminated area, don’t move any soil or debris to another area. It will contaminate it.

Plant crops not susceptible to nematodes in that area. Sanitize your tools including the roto-tiller tines with a 10 percent bleach solution.

In severe cases you might have to relocate the garden to another spot. Keep the area weed free as weeds may function as hosts for nematodes.

Rotating the plants on a three-year rotation will also help. It will also keep diseases at bay.

Broccoli, cauliflower, grain sorghum or millet can also lower nematode numbers. Rye grown as a winter cover crop works well.

Canola varieties such as humus and dwarf essex have been reported to be toxic to nematodes. Canola can be grown all winter and plowed under in March.

Sterilize the soil by solarization. Tie down a 2 to 4 mil clear plastic sheet over the affected area for at least two months. This should be done during the months of June through August.

Wet the soil thoroughly before placing the plastic down. Plant a fall crop or cover crop without tilling into the soil. This procedure may work.

Increasing the organic matter, liming and fertilizing to soil test recommendations will also help reduce nematode populations by helping the beneficial nematodes provide biological control.

Running out of time to sign up for the upcoming Master Gardener program

Troup County Extension is hosting the Master Gardener Extension Volunteer Program starting Aug. 9.

If you wish to hone your skills in horticulture and related subjects this might be the program for you. We have a variety of topics lined up and taught by excellent instructors.

We will cover a wide range of topics: botany, entomology, soils, plant nutrition, insect control, vegetables, herbs, plant propagation, planting and maintaining ornamentals, troubleshooting, pollinators, turf, trees and much more.

If you have your Tuesdays and Thursdays available and are willing to help out UGA Extension, send an email or call the office for more information. Please apply as soon as possible. We need at least 10 to sign up.

What’s going on in Extension?

Master Gardener Extension Volunteer class will begin Aug. 9 and run through Oct. 20. Classes will be held Tuesday and Thursday afternoons. The cost is $150. Call or stop by the office for an application.

Georgia Master Cattleman Program starting Sept. 6. Call for more information.

Beekeepers Meeting: July 18 at the Ag Center at 7 p.m.

Market on Main: Every Saturday morning from 8 a.m. to 10 a.m. Come by and enjoy the pick of the day. Carmike Cinemas LaGrange 10 theater parking lot at Main and East Depot streets.

If you have any questions or concerns, stop by or call the Extension office.

By Brian Maddy

Contributing columnist

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church St. in LaGrange and may be reached at 706-883-1675, Monday–Friday 8 a.m.–noon and 15 p.m.