“For years, we in the Chrysanthemum sector have been searching for the best method of controlling thrips. With the arrival of the predatory mite Montdorensis and the feeding mite Power Food, we have had a good biological approach to the first and second larval stages of thrips for a few years now. However, the approach was not yet complete, because adult thrips were not controlled. This has now been achieved in combination with the new variety Orius and Power Food Plus. With this, thrips in chrysanthemum is solved in the future!”

This is Aalbert Ekelmans, chrysanthemum grower in Tuil. We speak to him in a double interview with fellow Chrysanthemum grower Kim de Waal in Tuil. Both have carried out intensive trials with the new Orius variety in combination with the new Power Food Plus in recent months and both are very enthusiastic. 

Sensation has been working intensively on biological thrips control with the predatory mite montdorensis for more than five years. "For years, we have been keeping a close eye on the good results achieved in other chrysanthemum crops in controlling adult thrips using the Orius predatory mite. But we couldn't get Orius going in chrysanthemum. The insect needs pollen to produce offspring. Moreover, we have a short cultivation cycle; in 9-12 weeks a young cutting is planted and an adult flower harvested again and that is short to build up a population of predatory bugs." Aalbert says that in 2019 he was already involved in the first field trials of a new variant Orius at the request of Royal Brinkman and Agrobío. This variant Orius originates from an area where there is less pollen available and it can reproduce in crops without pollen. Conrad van Doorn, Royal Brinkman crop protection specialist: "AgroBío, the supplier, put a lot of effort into selecting this Orius variety together with the Universidad Politecnica de Cartagena in Murcia, Spain, under the direction of Professor Pablo Bielza Lino. Last year at Nursery Sensation we already saw that this Orius was doing well and we experimented with a Power Food supplemented with Artemia eggs. Agrobío then worked hard to formulate the best supplementary feeding diet for Orius; four ingredients are now mixed in the Power Food Plus. "Aalbert: "We immediately saw three to four times more offspring and that was a good prospect. This year we have been testing the new Orius in combination with the new Power Food Plus. The results are very good and thrips is completely under control here. There is even no more thrips reproduction here.”

​​​​- Aalbert Ekelmans, Sensation​​​

At Chrysanthemum nursery Sensation and De Waal, Orius was spread loosely and manually over the young Chrysanthemum crop once at the beginning of cultivation. The predatory bugs then receive extra Power Food Plus every week. This supplementary feed is distributed uniformly over the crop via the bio-distribution system on the spraying robot. An additional advantage is that Orius also eats aphids, leaf-miner, caterpillars' eggs and larvae.

At De Waal nursery, the reason for starting the Orius trials was completely different: a thrips infestation that had got out of hand at the nursery. Kim de Waal: "We grow fluff chrysanthemums and in this crop it is even more difficult to control thrips properly. The flower bud remains on the crop for at least four weeks before it is harvested and thrips likes to crawl deep into the bud and cause a lot of damage. Chemical spraying is not the answer, as it does not succeed in reaching the inside of the flower. We were faced with a major dilemma," says Kim de Waal. "On the one hand you want to opt for a biological approach, but on the other hand the thrips pressure was very high. We caught at least 200 to 300 adult thrips on a sticky trap. On the other hand, chemical control was also no longer possible due to resistance to the active ingredient." After the good experiences at Sensation nursery, specialist Conrad van Doorn of Royal Brinkman advised to start with the new variant Orius with Power Food Plus. 

​​​​- Kim de Waal, Charysanthemum nursery De Waal in Tuil​​​

It was a big step to change the course to 100% organic in June 2020, when the trip pressure was so high, at the most difficult time of the year. Kim: "But actually, we didn't have much of a choice, so we gritted our teeth and went for it. We had seen the good results at Nursery Sensation and were connected to the first practical trials with the new variant Orius and Power Food Plus." Kim de Waal explains that in the first few weeks after introducing biology you really have to be able to muster up the patience not to intervene chemically. "We started with the predatory mite montdorensis, the predatory bug Orius and the feeding mite Power Food Plus. After 4/5 weeks, we saw the first results and the number of thrips on the sticky traps went down to 80/100 per tray. Still a lot, but the first result was there. In the meantime, seven months have gone by and we are halfway the turnaround with only 10 to 15 trips per sticky trap. We totally believe in this approach; meanwhile we find one Orius predatory bug in every flower we tap. Look, then you are on the right track and you know for sure that the thrips do not survive. It will be a while before we can interrupt the reproduction of thrips here too, but the effort will pay off! When you see where we have come from and where we are now in four or five months, I can recommend it to everyone.”

Kim de Waal and Aalbert Ekelmans agree that these two new products are an important addition to the further rise and improvement of biological crop protection in Chrysanthemum. "It is a thorough and solid control method; it benefits the image of chrysanthemum, and we are taking big steps forward."

At the moment, this new successful system in chrysanthemum of Orius and Power Food Plus is being used in several ornamental crops with major trip problems. The combination with Power Food Plus is also a great improvement in the pepper crop, for example. 

​​​​- Michael Visser, Royal Brinkman​​​

Can't find your answer? Fill out the contact form and our specialist Michael Visser will get back to you. On weekdays, even within 24 hours.