With artificially lit tomato crops now underway, timely introduction of Biobest's confusion pheromone, Isonet® T*, will help prevent Tuta absoluta from becoming a pest. "To be successful it is important to use this mating disruption product preventatively and to start the crop clean," says Biobest advisor, Bart Elseviers.
Isonet® T is a filament-shaped dispenser loaded with scent from female moths. Bart: "by using it preventively, hanging 800 to 1,000 strips per hectare, males cannot find the females. As a result, mating does not take place. Although quite a costly solution, it works very well in practice. The number of moths must be limited, otherwise they will still find each other."
To be successful it is very important there is no tomato leafminer moth pressure at the outset – carried over from a previous crop or from other greenhouses or the plant propagator. "If larvae and/or adults are present at the start, we recommend applying a chemical spray to start clean,” says Bart. “Once growers have built up the biology in the greenhouse, these chemical interventions are no longer an option.”
Every 3 months
Bart advises growers to hang the Isonet® T dispensers as low as possible, as the pupae fall to the ground to hatch. "Place the strips between the plants or on the gutters – below a height of 1.5 metres," he says.
“The strips work for around 3 months, although in high temperatures the fragrance can evaporate a little faster. By weighing the strip, growers can see if it still contains pheromone.”
“Most growers introduce Isonet® T three times per crop. Those who consistently follow this advice have very few issues with Tuta absoluta," he concludes.