Information from Aggie Horticulture: Cereal Rye for Nematode Control
Author: Dr. Jerry Parsons, Extension Specialist
Nematodes are small, microscopic, worm-like animals that live in the soil and feed on the roots of developing plants. Although several different types of nematodes occur in vegetable gardens, the root knot nematode, which causes galls or swellings on plant roots, is the most damaging. Infested plants usually are stunted, yellow in color and often die prematurely.
When removing garden plants, examine root systems for the presence of nematode “knots” or galls. In extreme infestation, knots may slough off and not be present when plants are removed. Good healthy roots should be white and firm if not damaged by nematodes. Roots which are decayed or rotted may indicate the presence of nematodes.
If nematodes are found in your garden soil, plant cereal rye (Elbon) in the fall to lessen nematode damage to your spring garden. After several years of testing, cereal rye has proven to be the fastest growing, most cold-tolerant annual grass available to home gardeners in Texas. Plant cereal rye in the fall for a thick mat of grass 10 to 15 inches high by late winter.
This grass should be shredded with a lawn mower or flexible string trimmer and tilled into the soil so that decomposition can occur before you plant in the spring. Usually, shredding and tilling one month before planting will allow for adequate decomposition.
There are many advantages to this practice of planting cereal rye in your garden. It beautifies the area with greenery. It will add high levels of organic matter to the garden soil. This type of “green manure” crop decomposes rapidly.
If these benefits were not enough, the roots of cereal rye serve as a trap crop for nematodes. Once nematodes enter the cereal rye roots, they cannot escape and are doomed. When cereal rye decomposes, it releases organic acids and stimulates soil microorganisms which further reduce the nematode population.
Be careful to purchase cereal rye (Elbon) rather than annual rye. Annual rye is used to overseed lawns and should not be used in your vegetable garden. Cereal rye can be planted by merely seeding directly on top of the garden soil and raking in. Apply seed at the rate of 3/4 to 1 pound per hundred square feet of garden area to insure good coverage and adequate growth. Be sure to water the rye regularly and lightly fertilize every three weeks to encourage maximum growth.
Remember that the majority of the organic material produced is in the root system rather than the top foliage. This is a case of “what you don’t see is what you actually get!” Always mow or shred the cereal rye before it forms seed heads since sprouting rye seed in early spring may become a nuisance. There is no danger of cereal rye seeded in the fall becoming a weed problem during the spring since the plants cannot withstand the hot Texas temperatures. Shred the plants and till the soil one month before planting your spring garden so the massive root system will have adequate time to decompose.