References

Sjaak van der Hulst about Alsa

Van der Hulst rose grower

Sjaak van der Hulst grows roses on coco peat, together with his sons Mark, Koen, Paul, daughter Linda and daughter-in-law Dorothea.

In their 5 hectares of greenhouse, they grow the Aqua, Passion, Ruby Red and Sphinx varieties.

They have been using Alsa for many years, every week, all year round.

"We only correct by chemical means in the summer, this is often due to the harvesting time of sweet corn and grass outside, for example. For the rest of the year, we can suffice with using Alsa", says van der Hulst.

 

One of the cultivating measures is also to remove mature flowers, in which thrips can easily hide. The crop will never be entirely thrips-free, but a few of them will not damage the flower. Even in sensitive varieties! "Thanks to Alsa, I also have less problems with lice and caterpillars."

Depending on the temperature, Van der Hulst uses 0.5 to 2 litres of Alsa per hectare per week.

"In spring, we use half a litre per hectare, gradually increasing the dose to 1.5 to 2 litres per hectare as it gets warmer and the thrips more active."

Van der Hulst is trying to use Alsa for even better regulation, by increasing the dosage slightly earlier as the weather warms up.

Van der Hulst concludes with satisfaction: "Alsa is an effective way for me to keep thrips out of my roses."