CATT: A new and non-chemical pest and nematode control method in strawberry planting stock

As an alternative to MeBr fumigation, a 48 h controlled atmosphere temperature treatment (CATT) was developed and scaled up by Wageningen UR in cooperation with the Dutch plant propagating association Plantum. This results in an excellent deinfestation and 99.8% mortality of the strawberry tarsonemid mite (Phytonemus pallidus). This non-chemical and sustainable method provides a healthy production of high quality strawberry runners in the field. From 2009, CATT was scaled up to a commercial level and widely applied by Dutch nurseries. In 2011, this CATT method was successfully modified to also eradicate the root knot nematode Meloidogyne hapla (>99.7% mortality), which was not effectively controlled by MeBr fumigation. For an effective killing of the root knot nematodes, temperature must be raised to 40°C. In several experiments, the optimum conditions for high mortality of both tarsonemids and nematodes were studied. An adapted version of CATT was developed of 20 h at a temperature of 35°C and 50% CO2 followed by 20 h at a temperature of 40°C. In 2012, this adapted CATT was successfully upgraded and tested under field conditions. Additional research in 2013 led to the conclusion that cross infection of plants by the bacterial Q-disease (Xanthomonas fragariae) during CATT treatment is unlikely.