Traditionally, whitefly in gerbera is one of the regular but uninvited guests. Much is possible in terms of biological control, but the range of remedies that can be grabbed at any time is getting smaller and smaller. In short, it is a challenge, and it is under these circumstances that, at the suggestion of supplier Van Iperen, Eric Kerklaan of HortiPro came for coffee at EveryD Flowers in De Lier.
HortiPro is a company specializing in biological crop protection and all kinds of adjuvants and pheromone technology. Hortipro R&D was looking for a company struggling with whitefly and with which they could work together to find an effective control. The plan was to develop a new pheromone, which, zooming out, would be another step towards the fullest possible Integrated Crop Management.
Left to right: Eric Kerklaan and Lennart Simonse of HortiPro and Hen Groenewegen and Marian van Bergenhenegouwen of EveryD Flowers
After a year or so of testing and constant counting and scouting, we can report it worked. At the end of this year, the pheromone (PheroDes monitoring system for greenhouse whitefly and PheroBem for monitoring for Bemisia, or tobacco whitefly) will be on the market. Great to mention, moreover, is that it was developed here, at this garden, and in close cooperation between Eric Kerklaan and Lennart Simonse of HortiPro on the one hand and Hen Groenewegen and Marian van Bergenhenegouwen of EveryD Flowers on the other, and of course entirely for the benefit of both parties.
You pipette the pheromone onto a strip of absorbent material, which you then put into a dispenser. Inside it is a hole through which the pheromone can evaporate. You place the whole thing in a 14 mm hole in a sticky trap, which lures the adult whiteflies to a yellow sticky trap. As a direct result, a large part of the whitefly population is captured. So, where people used to be scared to death if there were 100 on a sticky trap, they are no longer surprised. Especially for Bemisia tabaci, which is more difficult to control than the 'normal' greenhouse whitefly, this is a godsend.
"We've learned a lot in recent years," Hen and Marian, grower and responsible for crop protection, respectively, tell us. "We are there earlier in terms of spotting pests, especially because we are scouting more. So we have a better picture of what is flying around. Therefore, unlike before, we are less behind the times, and that is crucial because intervening at a later stage is disastrous for your biology. Because we catch a lot of flyaways, we have also changed the spraying schedule considerably. We use almost no chemical anymore, correcting is done almost exclusively with green agents."
A whole zoo can be discovered on a random leaf (click image for large size)
Not on holiday
In short, it may be called a success story, but it does have one downside: you can't go on holiday. Eric: "Pheromones can be a solid basis for a healthy crop protection strategy, but you have to stay on top of it. Preferably with regularity, counting, and scouting should be done. Not once in a while, not just when you have time, but consistently. If you slacken off in this respect and a plague returns, you will immediately fall behind again. Even, or perhaps especially, when you think you are rid of something, it is important not to slack off."
For more information:
HortiPro 
[email protected]
www.hortipro.com
EveryD Flowers
https://everydflowers.nl