The Netherlands
Commercial applications in the Netherlands
In the table below the results of all 359.380 elms treated in the period 1992-2007 in The netherlands are summarized. These figures concern commercial treatments, and show the same success rate of the treatment as was found in the US. On average, approximately 1% of all treated trees dies of DED; half of them (0,5%) because of root graft or old infections, for which the preventative vaccination with Dutch Trig offers no protection.
Even though the disease rate amongst Dutch Trig treated trees has been fairly constant around the 1% average (which is low compared to the natural losses of Dutch elm disease ranging from 5-15% per year), the last years show a significant decline in average disease incidence. This improvement of treatment performance is not caused by a low natural disease pressure, because elm bark beetle-trap counts indicate a never subsiding high disease pressure over the entire country. The last years a lot of extra effort has been put into optimization of Dutch Trig cooled transport, production and better practices concerning hygiene and accurateness for the arborists doing the injections, which could very well be part of the cause of the decline in disease incidence in the Dutch Trig treated group in The netherlands.
