Green Challenges: De ziekte- en plaagdichte kas

Prevention is an important pillar in the control of diseases and pests in the greenhouse. This report gives an overview of the different routes of entry for pests and diseases, the importance of these routes, and methods and possibilities for prevention. The (semi-)closed greenhouse and a clean corridor for material and people could offer options to reduce risks of entry. Surveys and workshops with growers indicated that they questioned the importance of diseases and pests entering the greenhouse through ventilation windows, but that they saw perspective in a clean corridor. Therefore, the study paid specific attention to these topics. The importance of entry of winged insects by the ventilation openings was monitored but this limited trial did not reveal a strong relationship between the amount of insects outside and inside the greenhouse. A design has been made for a clean corridor, with detection and treatment options. In addition, the possibility of removing insects with an air shower and a detection method for mildew spores were specifically examined. The air shower does not seem to offer an effective and safe solution for horticulture at this time. The mildew spore pressure could be quantified with the selected approach. These are just two examples of an elimination and a detection tool that can be part of a clean corridor; it is recommended to investigate various other techniques as well.