There is a lack of practical information and practical knowledge for farmers to apply organic plant protection products and biostimulants in potatoes in a proper way.
For both organic plant protection products and biostimulants, two thirds of potato growers have used these products. Most of them stop if they don’t see a visible result of their spraying.
This is the result of a graduation study by student Cor Kruiswijk of Aeres University of Applied Sciences Dronten. On behalf of The Zwaagdijk Experimental Garden, he investigated the main factors why potato growers make little use of green resources. The study consisted of a survey of thirty potato growers and in-depth interviews with seven growers and eight crop protection experts.
A conclusion of Kruiswijk is that many potato growers still prefer chemical controls in order to avoid cultivation risks. ‘The growers are not negative about the use of green resources and recognise the need to be less dependent on chemistry. Important concerns are the lesser operation and the often higher costs.’
The crop protection experts who spoke to the student estimate the effectiveness of green products at 50 to 60 percent and for chemicals at 80 to 90 percent. ‘As a result, the chemistry crop protection is still more familiar. Furthermore, many growers indicate that they lack the reward in sales to switch to more expensive resources with less environmental impact.’
Now mainly scientific
In addition to regulation, the development of more practical knowledge about the application of organic plant protection products and biostimulants is an important factor in encouraging use. ‘In growers, there is a view that green resources are mainly scientifically researched under controlled conditions. They advocate more practical research’, explains Kruiswijk.
For The Zwaagdijk Experimental Garden, the findings in the graduation assignment are very valuable, says innovation manager Joris Roskam. ‘It’s confirmation that we need to put green resources more at the heart of research. We know that this type of resource requires a different way of applying them. Growers have practical questions about the correct use and also, for example, about spraying techniques that give the best result. We have to try to find the answers to these questions.’