CATT as a non-chemical pest and nematode control method in strawberry mother planting stock1

Abstract

Abstract. Until 2008 methyl bromide (MeBr) was used in The Netherlands for fumigation of strawberry runners, intended as mother planting stock, to make them free of contamination by strawberry tarsonemid mites (Phytonemus pallidus). As an alternative of MeBr fumigation a 48 h CATT method was developed and scaled up by Wageningen UR in cooperation with the plant propagating association Plantum. This results in an excellent disinfection and a mortality of 99.8% of the strawberry tarsonemid mite. This method provides a healthy production of highly qualified strawberry runners in the field. From 2009 CATT is up scaled to a commercial level and widely applied by Dutch nurseries. In 2011 this CATT method was successfully modified to eradicate also root knot nematodes 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 for a high mortality of both tarsonemids and nematodes was studied. This leads into an adapted CATT of 20 hours at a temperature of 35• C and 50% CO 2 followed by 20 hours at a temperature of 40 • C. In 2012 this adapted CATT was successfully upgraded and tested under field conditions.

Control of Phytonemus pallidus (Acari: Tarsonemidae) from strawberry transplants using controlled atmosphere temperature treatment

“…The 99.9% reduction of P. pallidus in this study is comparable to the mortality rate reported in previous research (van Kruistum et al 2011, 2014, Verschoor et al 2015) when strawberry plants were treated at 35 °C, 50% CO 2 , 10% O 2 , and high relative humidity for 48 h. Phytonemus pallidus is well protected from most acaricides and predatory mites because it lives hidden in the leaves and crowns of strawberry plants (Easterbrook et al 2001, Fountain et al 2010); however, CATT is highly effective because the plant does not provide protection from heat, high CO 2 and low O 2 levels in the atmosphere. While heat increases respiration rate, restricted amount of O 2 available to P. pallidus causes its suffocation (Mitcham et al 2006).…”

“…The controller was operated with a computer program created using the Cscape PLC Software 9.90 (Horner APG, 2020). The program specified a temperature of 35 °C, a relative humidity (RH) of 92%, a CO 2 concentration of 50%, and an O 2 concentration of 10% (van Kruistum et al 2011, 2014, Verschoor et al 2015). A proportional–integral–derivative (PID) control loop mechanism was used to regulate temperature and atmospheric conditions.…”

“…When strawberry transplants were treated at 35 °C, 50% CO 2 , 10% O 2 , and high relative humidity during 48 h, 99.8% of P. pallidus were eliminated without affecting plant vigor (van Kruistum et al 2011). To control for the root knot nematode ( Meloidogyne hapla ), a pest of strawberry, CATT parameters can be adjusted with a first 20 h phase at 35 °C followed by a second 20 h phase at 40 °C (van Kruistum et al 2014). Commercial application of CATT against P. pallidus is offered at a large scale on mother plants by 2 specialized companies in the Netherlands (Verschoor et al 2015).…”

Fytosanitaire na-oogst behandel- en detectietechnieken voor plaagorganismen in tuinbouw

“…Het zal echter niet voor alle plaag-product combinaties tot een effectieve behandeling zonder kwaliteitsverlies kunnen leiden. CATT-behandelingen (Naar: Neven and Johnson, 2017, nog niet gepubliceerd (van Kruistum et al 2014, Verschoor et al 2015 *Combinatie CATTS met daarna gekoelde opslag (7 weken @ 0°C). ** De projectgroep die deze behandeling financierde heeft geheimhouding van het gebruikte zuurstofgehalte afgesproken 1.1.1.1 Effect van CA op afdoding ongewenste organismen Ongewenste organismen zoals insecten, mijten of nematoden blijken niet altijd met een lineaire respons te reageren op verschillende CA condities en hoge temperaturen.…”