‘Ornamental plant companies need to innovate more in plant protection’

^{Martijn Roos amongst the poinsettias. Green'05 has been growing these plants without chemical agents for three years now.}

‘If we don’t do anything, we will inevitably run aground with our plant protection. The number of chemical agents available is quickly drying up and its use is becoming more and more strictly regulated. We growers need to move forward with biological plant protection. We have to innovate more – there’s no other way.’

These forceful words come from Martijn Roos. He is the plant protection specialist for the entire company at Green'05 in Bergschenhoek, the Netherlands, which, with seven locations and a total of 33 hectares, is by no means small.

There are good reasons why Martijn stresses the need for innovation so emphatically. Green'05, owned by Arco van der Kaaij, delivers more or less directly to large retail chains in Europe (such as Aldi, Lidl, and Tesco), to the major home furnishings retailer IKEA, and to DIY chains. ‘They are constantly tightening their criteria when it comes to the products used and residues. An example? When Closer was authorized for the control of whitefly, our buyers immediately prohibited us from using it.’

Martijn started working for the producer of green and flowering pot plants and bedding plants ten years ago. He looks back for a moment at the type of plant protection used back then. ‘After a couple of years, I came to the conclusion that we were in the process of spraying ourselves to oblivion. All pests and fungal diseases were combated with chemicals. This would take you three-quarters of the week to do but you didn’t really make any progress at all. And, of course, chemicals never provided any real solution.’

It was for this reason that Green'05 decided to switch to integrated pest management in 2012. This was no small task in a company that had so many different crops, a complex and busy internal logistics structure, insects regularly flying in from outside, and buyers that barely permitted anything.

^{Green'05 determines the strategy as regards the beneficials to be used based on the scouting observations. Thorough scouting is essential during the cultivation period.}

Nevertheless, the company has now made significant progress in terms of biological plant protection. One example is the cultivation of poinsettias. These are mainly exported to the UK. Although it is a relatively small crop for Green'05, the UK market operates a strict zero-tolerance policy. If an inspector were to find tobacco whitefly, for example, the alarm would sound immediately. In other words, trading would cease completely. This is why the company is pulling out all the stops to produce poinsettias without the aid of chemicals.

‘In a trial we are involved in together with Koppert, this is something we have succeeded in doing over the past three years,’ Martijn explains. ‘Together with the consultant Richard Saarloos, we determine our strategy based on scouting observations. After all, measurement is the key to knowledge. We then release a mix of the predatory mites Montdo-Mite (Transeius montdorensis) and Swirski-Mite (Amblyseius swirskii) and the parasitic wasps Ercal (Eretmocerus eremicus) and En-Strip (Encarsia formosa). These four teams keep thrips and whitefly completely under control. There is no need anymore to spray the product clean when the delivery date is approaching. In addition, spraying kills all the beneficials even though they do their job 24 hours a day.’

Much of this success, according to Martijn, depends on a clean start of cultivation and exceptionally good scouting. ‘That is very important. Scouting takes a very long time with poinsettias, but in the end we reap the success.’

Martijn Roos sees innovation as a core activity of Green'05. For instance, the company has developed an organic alternative to chemical fungicides that is very effective. ‘But this type of success doesn’t simply happen overnight. All in all, it took us over eighteen months to get this far.’

Green'05 is also successful in the organic cultivation of bedding plants. ‘We specifically wanted to grow our bedding plants with as few chemicals as possible. Our colleagues more or less said we were crazy, which is understandable as it is indeed very difficult. And yet we succeeded. We are probably now the only supplier of bedding plants in the Netherlands that works entirely organically.’

There is another reason why Martijn thinks that growers’ firms should innovate in their plant protection methods – new types of pests. ‘Echinothrips have now becoming established in the poinsettias and the cabbage fly is new to the crop. We need to find solutions to these new threats. As broad-spectrum products are no longer becoming available, more and more pests are appearing in the crop that would normally not be there. Hopefully, Koppert will soon have new biological beneficials for this problem.’