Development of a UVC application machine for managing plant diseases in soilless greenhouse crop production

This study aimed to develop a UVC machine designed for the treatment of common fungal, bacterial, and viral diseases in greenhouse-grown crops, serving as an alternative to chemical applications. The machine utilizes standard battery carts or trolley infrastructure for mobility along heating pipes in greenhouses. The machine is equipped with 8 UVC lamps, four on each side, each having a power of 145 W and a length of 1.5 m, complete with reflectors. The lamps can be adjusted both vertically and horizontally to optimize their positioning based on the crop conditions. Two 24 V switches control the lamp power levels according to data received from the microcontroller. Each lamp can be controlled via software, allowing them to be turned on or off as needed. The lamps on either side of the machine can be operated independently to provide the specific dosage required for treating plant diseases within a range of 5 to 100 mJ/cm². UVC doses were measured at various machine speeds and lamp-sensor distances. Statistical analyses confirmed a significant effect of PWM speed on UVC dose (p < 0.05), demonstrating the inverse relationship between machine speed and accumulated UVC exposure. The UVC machine has proven effective as an autonomous device for crop disease management. Operating the lamps at slower speeds increases the dosage but may delay treatment, which is critical for stopping the spread of diseases or pests.