Nearly two years ago, Leon Kouwenhoven, cultivation specialist at OK Plant in Naaldwijk (the Netherlands) faced a challenge when deploying his biological controls. He uses montdorensis against thrips, but noticed that he couldn't distribute his predatory mites evenly. He observed more thrips pressure on the sides than in the middle of his greenhouse covers. To solve this, he adjusted his blowers to direct more towards the outer edges. The result was lower thrips pressure at the edges of his covers, but increased pressure in the middle. "I was essentially moving the problem around."
Henk van der Meer, crop protection specialist, visits OK Plant regularly. He noticed Leon's challenge: "An even distribution of the biology is particularly important with orchids because the plants are in vases. If a predatory mite is in a vase, it's unlikely to move to another vase." Leon asked Henk and account manager Gerard Bok to help him find a solution to this problem.
New distribution system
Recently, Pligt Professionals asked Henk and Gerard the same question as they faced a similar challenge. A new distribution system for biology had to meet several criteria.
- Safe for biology
- Easy to use
- Even distribution over the covers
- No use of wind
The new biology distributor with the old blowers above. These are now redundant and can be dismantled.
With these criteria in mind, Gerard and Henk spoke to several manufacturers. Wim van Wijk Techniek ultimately came up with a suitable system. In this system, the biology is in tubes that hang across the entire width of the cover. When the system is activated, the tubes rotate and the biology falls on the crop through holes in the tubes. "Since the tubes hang directly above the cultivation table and no wind is being used, there are virtually no predatory mites falling outside."
As is the case with blowers, the system moves back and forth 'independently'. Upon initial use, the travel speed and rotation speed must be set at once to distribute the desired amount of biology evenly over the cover. After that, nothing more needs to be done. Leon: "It's a matter of turning it on and waiting for it to return. In the meantime, the tubes can be filled for the next cover."
Working together to find solutions
Gerard and Henk invited Leon to Pligt Professionals to take a look at the system. Leon was enthusiastic and has been using the system in his greenhouse for over a year. "From that moment on, the thrips pressure has been much lower. It just works well, and we didn't have to change anything." Gerard and Henk are always looking for things that can be improved. "But these improvements are concerned with details."
Research with other biology
In cultivation, Leon mainly uses montdorensis, but other biological crop protections can also be distributed through the tubes. Gerard: "Our team of practical researchers continues to investigate how other insects emerge from the different systems. We want the lowest possible mortality and also as few broken wings or legs as possible."
To investigate this, a cultivation gutter with petri dishes is mounted under the tubes. Here, the biology is collected and can be analyzed. "By testing different types of insects, we try to get the most complete picture of the mortality. We test predatory mites and feeder mites, but also beetles. This new system ensures that virtually all tested biology arrives alive and intact in the petri dishes, as has been experienced by growers."
For more information:
Van Iperen
[email protected]
www.iperen.com