Best practice of applying Nemasys G & Nemasys J

Nemasys G contains the beneficial nematode Heterorhabditis bacteriophora and is available in packs of 50 and 250 million nematodes. Nemasys J contains the beneficial nematode Sterinernema feltiae and is available in packs of 250 million nematodes. Both products come in a water dispersible carrier and are manufactured by BASF at Littlehampton, UK.

Beneficial nematodes are effective biological control agents that are safe to users and the environment. Most turf specialists use chemical methods to control pest problems, however insects are known for their ability to develop resistance to synthetic chemicals and some pesticides may be non-specific and kill beneficial insects. That added to the increasing legislation and withdrawing of existing chemical controls, has increased the use of natural biological control agents as part of an integrated pest management programme for controlling pest populations.

Climate change related factors like warmer temperatures, changes in rainfall patterns and milder winters can have a direct effect on insect populations by affecting their development rate, reproduction and distribution. Furthermore, indirect effects can occur through the influence of the weather conditions on the pest’s host plants, natural enemies and interspecific interactions with other insects. Milder and shorter winters are likely to result in an upsurge of pest populations under warmer and wetter conditions in the UK, particularly in the South. Beneficial nematode applications have shown an effective control of major turf pests.

Challenge of application

The biggest challenge of nematode application into turf is to penetrate the thatch layer in order to reach the soil where the Chafer grubs and Leatherjackets are found. The larvae of both pests feed on grass roots at the bottom of the thatch layer. Nematodes are contact acting and move in water, hence the recommended dose and application volume should be followed to ensure good contact between the target pest and the nematodes.

Application guidelines

In taller swards, such as rough/fairways, it is recommended to cut the turf prior to application to facilitate nematode penetration into the soil as well as to ensure the soil is moist (ideally apply during rainfall) for at least two weeks after application. Use of soil moisture monitoring probes can be used to map the area treated.

The soil temperature should be between 12oC and 30oC and the application done early morning or late afternoon/evening to avoid direct sunlight as the nematodes are killed by UV light. It is advisable to irrigate immediately after application to move the nematodes left on the turf surface below the thatch layer; the use of a wetting agent will greatly improve the movement of nematodes to the target pest. Treatments should be applied when chafer grubs are present and close to the soil surface, usually in August/September (during late October/November grubs move deeper in the soil making them difficult to target).

Directions for use

Remove all fine filters (50 mesh or smaller) from the application equipment. Empty one pack of nematodes and put contents in a bucket (figure a).

Figure A

Rinse packaging with a small volume of water to ensure all nematodes are washed into the bucket (figure b).

Figure B

Add the remaining volume of water required (minimum 10 L) and stir to ensure that the nematodes are well dispersed, making sure the entire product is mixed thoroughly (figure c).

Figure C

Add nematode suspension into the tank through its sieve. Fill tank to the required water level and apply immediately to the whole area at the appropriate rate.

Irrigate immediately after application with up to 3 litre of water per m2.

Product handling

Agitate nematodes constantly during application. Use of specific nozzles that allow spray penetration to the soil surface, such as the Syngenta XC nozzle 08, should be considered to improve soil deposition through the thatch layer. Suitable nozzles should produce a medium or courser spray the intended application pressure (nozzle aperture greater than 0.5 mm). Do not exceed 300 psi/20 bar/2000 kPa pump pressure.

Use entire contents of pack at one time, do not split or subdivide individual packs as each contains a measured dose of nematodes and use immediately or store in a refrigerator at 5oC upon receipt. Do not freeze as forming ice crystals will rupture the nematodes. It is also important to remember not to use the product if past the expiry date or it has been incorrectly stored. For information relating to which chemicals are compatible with Nemasys G or Nemasys J ask your distributor.