Turf pests such as Chafer grubs and Leatherjackets can be sucessfully treated with nematodes in the mid-late summer.
The eggs laid by Chafer beetles in May and June will develop into larvae or grubs by about the end of July. They will feed on grass roots until the autumn, once soil temperatures start to drop , the grubs will stop feeding and sink lower down in the soil structure , where they will overwinter. The best time to treat Chafer grubs with nematodes is when they are quite small from July-September. They are more vulnerable to nematodes when they are smaller and the soil temperature at this time of year is also high enough for good nematode activity. The same applies to Leatherjacket larvae , which can appear slightly later in the soil from mid to late August through until the autumn.
When applying nematodes there are some important tips guidelines that should be followed to maximize the success of your nematode treatment.
The most important factor is water and irrigation. Nematodes are not able to operate in very dry soils. They need to be able to penetrate through the grass thatch and move into the soil beneath . Too little water and they will sit in the grass and never reach the soil. Also the soil must be irrigated , if it is rock hard or too dry, the nematodes will not be able to move through it. The grass area should also be irrigated or watered after application This enables the nematodes to continue moving through the soil searching out chafer grubs to infect and kill. It is good practice to keep the soil moist for a minium of 7-10 days after application of nematodes. For larger areas the addition of a soil penetrant or spreader will also aid the infiltration of the soil by nematodes. Dragonfli supply a nematode friendly carrier product called Nemaflo, which is added to the spray solution . This aids the penetration of the soil by the nematodes.
Nematodes can be applied with watering cans, sprayers or hose end feeders like the Aquanemix nematode applicator. This is simply attached to the end of a hose pipe and speeds up the process of applying nematodes over larger areas.
Other considerations to maxmize the effectiveness of your nematodes are;
- Try not to apply on bright days , as the nematodes are U.V sensitive
- Store nematodes in a fridge prior to application
- Apply all opened nematode packs, they will not store after opening
- Repeat applications of nematodes maybe required for severe turf infestations