Nematode Instructions & Information
Most beneficial nematodes which are raised on a dog food-like substance, the nematodes we sell are raised on insects (in vivo). Although this process is more costly than rearing on artificial media (in vitro), this technique produces a much more aggressive strain. What we sell are two different strains of nematodes because of their different abilities.
Steinernema sp. are shallow soil dwellers that occupy the top 1-3 inches of soil. These nematodes are ambushers and attach themselves to soil particles near the soil surface waiting for prey.
Heterorhabditis sp. burrow down as deep as 5-6 inches, offering a secondary barrier to grubs that are emerging from or submerging to winter soil depths. Because Heterorhabditis sp. reside deeper in the soil, they are less susceptible to drought conditions. Heterorhabditis sp. are hunters that follow grub exudates through the soil.
Both species act by invading grub or larval bodies through orifices, such as the mouth, anus, or spiracles, where they release bacteria that are symbiotic to them but deadly to the larvae. The bacteria multiply and produce enzymes that destroys the host's protein. Larval death occurs in 24 to 48 hours. The nematodes soon begin reproducing the next generation of offspring, which mature and reproduce another generation, which then reproduce a third generation.
The SF nematodes require both a male and a female to reproduce but the Heterorhabditis sp. can develop into a hermaphrodite and reproduce asexually. Steinernema sp. cycle in about 7 to 10 days from infection to emergence and Heterorhabditis sp. takes about 12 to 15 days. By this time the food supply from the host has been depleted and nematodes emerge in numbers that will often exceed 100,000. All of these hungry, microscopic juveniles go off in search of new larvae.
Nematodes are shipped alive and should be released into a thoroughly moist soil or growing media as soon as possible. They can be stored for a short period of time (about 1 week) under refrigerated conditions (40-50o F) but the small sponge that nematodes are shipped in must be kept damp and the package should be left open to allow fresh air to enter during storage. Add a few drops of water if the sponge appears to be drying out. When mixing, the ideal water temperature is between 65o and 80o F. DO NOT USE HOT WATER. Nematodes are nocturnal and should be released in the evening or at night. These nematodes will survive at soil temperatures between 32o and 90o F.
However, they are most aggressive at temperatures between 65o and 85o. They cannot survive at soil temperatures above 90o or below 32o F. Reapplication may be necessary if the soil reaches beyond these extremes. Most nematodes are very sensitive to sunlight. After 7 minutes, exposure to ultraviolet light will sterilize the nematodes. Therefore, it is crucial that Nematodes nematodes be watered into the soil quickly and thoroughly. Irrigate if necessary before applying to ensure that the environment is sufficiently moist and mow the lawn first and rake off excess grass clumps and anything that will block the nematodes from getting down into the soil.
Applications in the early evening or early morning are recommended. Nematodes can be applied through any modern liquid delivery systems and can withstand pressures up to 300 p.s.i. Filters should not be smaller than 50 mesh (i.e.) 50 openings per linear inch, or 0.020” sized opening). Optimum soil moisture for nematodes is ~15%. Like most beneficial organisms, nematodes work best when applied in anticipation of a grub problem. The "ounce of prevention vs. the pound of cure" rule is most appropriate with any predator insect. Concentrate the Nematodes nematodes where problems are most likely to appear or already exist.
Some chemicals to be used with care or avoided include aldicarb, carbofuran, diazinon, dodine, methomyl, and various nematicides. However, specific interactions can vary based on the nematode and host species and application rates. Furthermore, even when a specific chemical pesticide is not deemed compatible, use of both agents (chemical and nematode) can be implemented by waiting an appropriate interval between applications (e.g., 1 – 2 weeks). If you've already fertilized with synthetic fertilizer Nematodes are generally compatible with chemical fertilizers as well as composted manure though fresh manure can be detrimental.
FOR TURF: Nematodes can control many different varieties of lawn insects such as Japanese beetles, Asiatic beetles, European and masked chafers, sod webworms, June and May beetles and armyworms.
FOR GREENHOUSES: Nematodes is an excellent control for fungus gnat larvae, shorefly larvae, thrips and other greenhouse pests that spend part of their life in the soil.
FOR FIELD CROPS: Nematodes nematodes will parasitize many field crop pest larvae including onion maggots, strawberry root weevils, cabbage root maggots, flea beetles, black vine weevils, cutworms, carrot weevils and many others.
ORCHARD CROPS: Nematodes is an effective control of many soil-born pests that do not migrate from surrounding areas.
OTHER USES: Nematodes nematodes will attack and kill over 250 varieties of insect larvae in the plant root zone. Almost any species of plant feeding insect that spends part of its life in the soil is susceptible to attack by Nematodes.
1. Irrigate for 15 - 30 minutes immediately prior to Nematodes application to cool irrigation equipment and surrounding soil surface to temperatures below 85o F.
2. In the spring: Apply when soil temperatures are above 35o F. In the fall: Apply when soil temperatures are above 55o F.
3. Nematodes are compatible with most pesticides and fertilizers, but will do much better in an organic environment free of synthetic chemicals.
4. A nematicide should NOT be applied within 14 days before or after application of beneficial Nematodes.
5. Use cool water (50 - 80o F) to dilute and apply the Nematodes.
6. Triple rinse the Nematodes into feeder tank.
7. Agitate the Nematodes in feeder tank during mixing and application.
8. Prepare spraying equipment by removing or replacing screens that are U.S. mesh size 50 or smaller.
MIXING AND DILUTION
1. Saturate and squeeze the contents of the sponge or flask into tank water under active agitation. Rinse the sponge or flask several times.
2. Water temperatures should be between 50 - 80o F.
3. Tank agitation must be active during filling and application to ensure complete and even dispersion of the product.
4. Pump pressures should not exceed 300 PSI.
5. The Nematode suspension may be held in the agitated tank for up to 24 hours. Keep tank cool (under 80o F).
APPLICATION PROCEDURES - Home Use
a. Use a clean one gallon bucket and non-chlorinated water to make your solution.(do not use distilled water) If you need to, you can fill up a 5 gallon pail or larger container with your city water and let it stand for a few days outside to allow the chlorine to “gas off” into the atmosphere. Rain water works too, providing you don't have a lot of lead flashing on your roof. Do this a few days ahead of time so you have what you need, ready, by the time the nematodes arrive.
b. Squeeze out the sponge thoroughly into the 1 gallon container, until the water runs clean off the sponge. After you've used up all the solution, you can pick up the sponge and fill the watering can or sprayer again and go over the application area one more time if you like, just to make sure you got all of them off the sponge, but, this is an extra step for the frugal.
c. Pour the concentrate into your sprayer as needed. For small areas you can apply the nematodes using a watering can. They can be applied to turf, flower beds and shrubs areas as well, if you think your problem extends into those areas.
d. Take the filters out of your sprayer before applying the nematodes so they don't get caught up in the filters. Make sure the sprayer is clean of all synthetic chemicals and debris before applying the nematodes.
e. If you are unable to be home when the package is delivered you might consider placing a cooler near the front door (preferably out of direct sun) with some ice in it, with a note to the delivery person to place the package inside the cooler. If you choose to do this, please know that this will invalidate the replacement guarantee. Therefore, it is best if the you can be there when the package is delivered so they can be put in the refrigerator immediately.
f. The nematodes are guaranteed to arrive alive. Replacements or returns are allowed providing the you signed for delivery and put them in the refrigerator upon receipt from the carrier and/or applied as directed. Nematodes may be stored for approximately 30 days in the refrigerator. You must check the sponge for moisture and allow air into the package every couple of days during storage. Nematodes may be applied with any type of sprayer and can withstand up to 300 pounds of pressure per square inch. If using a hose end sprayer it may be helpful to add some natural food coloring to the solution so you can see it in the sprayer's receptacle. Remember to keep the solution agitated as the nematodes have a tendency to settle to the bottom. If you don't know the application rate for the particular sprayer then calibrate it before performing the application by doing the following:_ Set the sprayer at mid-point. Fill the receptacle with water and add some food coloring. Turn the sprayer on and walk in rows at a steady pace. When the receptacle is empty, measure the area covered at that setting. This is your rate of application.
g. For example: With the sprayer set at mid-point and a quart size receptacle you walked an area of 1,000 square feet you would mix a one-mil package of nematodes into two quarts of water and fill your receptacle twice to cover 2,000 square feet. h. Water the Nematodes into a thoroughly moist soil in the evenings as the nematodes are very sensitive to sunlight. Water well afterwards too.
a. Nematodes can be applied through fertilizer injection systems: wheel-line, in- line, fixed-line or other sprinkler type systems.
b. Irrigate for 15 - 30 minutes immediately prior to starting injection to cool the irrigation equipment and soil surfaces.
c. Add the Nematodes to a clean feeder tank. Suspension must be continuously agitated during injection to prevent the Nematodes from settling. Calibrate the injection pump to deliver the concentrate over a one-hour period or longer for uniform coverage.
d. After injection, rinse feeder tank with clean water and inject into system.
e. Follow post-application irrigation instructions.
a. Nematodes can be soil-applied using shank, cultivator or spoke-wheel applicator.
b. Apply Nematodes in 30 - 100 gallons of water per acre.
c. Shank: Apply as a trickle behind each shank at a 2 - 4 inch depth followed by a press wheel to cover opening.
d. Cultivator: Apply as a spray immediately in front of a rolling cultivator. Incorporate to a 2 - 4 inch depth. e. Spoke-wheel: Double spoke-wheels should be placed 6 - 8 inches apart and centered on the bill. Inject at a 2 - 4 inch depth. Ground Spraying - all Surface Spraying Equipment a. Apply Nematodes with a minimum of 100 gallons of water per acre. b. Soil should be moist before beginning application.
e. Soil temperature should be between 35 - 85o F. d. Follow post-application irrigation instructions.
1. Prior to application, ensure that soil is thoroughly moistened to the full depth of the root zone.
2. Surface application: Following application of Nematodes, immediately irrigate with 1/4 - 1/2 inch of water.
3. Subsurface application: Irrigate field no later than 3 days following application.
4. For maximum Nematodes performance, maintain adequate soil moisture for 21 days.
*A special thanks to Paul Sachs of North Country Organics@ for his years of support and contributions to this document and other valuable insights over the years. If you'd like to buy one of his books, you can find them at our web site: http://www.newenglandnatural.com