In March, cucumbers were planted at the research station for vegetable production in Sint-Katelijne-Waver to further develop the IPM-strategy against powdery mildew with a UV-C robot. From previous trials, it was concluded that a maximal dose of 50 J/m² of UV-C should be used to prevent negative effects on plant quality. By treating the cucumber plants 3 times per week with 50 J/m² UV-C light during night time, powdery mildew could be controlled sufficiently in the greenhouse. This year, it will be evaluated whether a lower dosage of 30 J/m² UV-C will have the same effect on the fungus without having negative effects on the plant quality. Moreover, a strategy is being tested where only the bottom halve of the plants, where the powdery mildew is most present, is being treated by the UV-C robot. This way, the growth point of the plant and the open flowers are protected from the damaging UV-C light. At the beginning of April, powdery mildew became present in the greenhouse and the UV-C treatments with the robot from Octinion could start. The results from this trial will be communicated as soon as possible.