Total approach to leatherjacket control

The combination of NemaTrident beneficial nematodes, integrated with targeted Acelepryn application, has been instrumental for Course Manager, Sam Evans MG, successfully managing extreme leatherjacket issues at North Hants Golf Club.

Such was the scale of the challenge that he’s been keen to utilise all available options in a total approach to leatherjacket control, with the use of Acelepryn and looking to add a further tier of control through beneficial nematodes. 

The strategy has been for an autumn application of NemaTrident nematodes and Acelepryn, typically in mid to late October and about 10 days apart. “The results have been incredibly successful, with no perceptible leatherjacket damage to playability on the greens over the past season,” he reports.

Sam advocates key to the success in managing the leatherjacket issues has been a series of incremental gains from multiple turf management practices. 

That is in part the control measures to significantly reduce pressure, but also making turf more resilient to the effects of pest numbers.

“Anything we can do to encourage turf health, early growth and recovery - though stronger rooting, nutrition, moisture levels and avoiding disease or other stresses on the plant - can help to overcome leatherjacket damage, or at least keep it at a level that does not affect playability,” he says.   

The ITM measures can also be important to the success of the NemaTrident application. Soil moisture levels that can be raised to help recovery from the pre-planned October renovation week, for example, are also highly beneficial for nematode efficacy in targeting leatherjackets in the soil. 

Although Sam aims for a soil moisture in greens of around 18% for optimum playability, that can be raised to near field capacity 30% at the time of nematode application, through a combination of natural rainfall and irrigation if required, depending on the season. 

Over the following days soil moisture is ideally be retained at around 25% for a week to 10 days after application – field capacity -5% being around the optimum for nematodes to have moisture to move, but still with sufficient air pockets for them to survive and be active. 

Greens are 9mm pencil tined prior to application to help move nematodes through the soil profile, but avoiding creating large aeration holes that leatherjackets could use for movement.  

The addition of NemaSpreader, which is put in each spray tank with the NemaTrident application, also helps the nematode movement and activity in the soil.

In addition to tracking soil moisture daily, Sam records soil temperature probe readings at a depth of around 100mm. The aim is to ensure nematodes are applied while soil temperatures are still above 8⁰C for at least 12 to 14 hours a day – with an eye kept on forecasts of weather patterns, and particularly temperatures, to optimise application timing.     

When the conditions are right, every effort is made to get the application on as soon as possible. The sprayer is prepared in advance, with all the filters removed – in both the pump circulation and the nozzle lines – and the large orifice white 08 XC Soil Nozzle fitted.

The spray tech is provided with a sheet with a reminder step-by-step checklist. That includes to remove the nematodes from the storage fridge 20 minutes before use and put them in the mess room to warm up, and then to mix in a bucket to get them active, before adding to the sprayer.

Then, time is imperative to prevent nematodes sitting in the spray water for too long. The plan is to get application out without delay and, if necessary, make multiple loads that be sprayed out quickly. 

Best practice is to irrigate immediately after application to wash nematodes down into the soil surface, or apply during light rainfall. 

They also calculate to make sure all the nematode packs in the refrigerated storage are used in the application.  

“Our primary focus has been on protecting greens, which so far has been successful.” highlights Sam. “Now we might look at trials to adapt the NemaTrident application rate and timing so that, for the same budget, we could extend treatment out onto tees and approaches,” he adds.