Precision disease control in bed-grown crops

Abstract

Matching spray volumespray volume to crop canopycrop canopy sizes and shapes can reduce the use of plant protection products pesticides, thus reducing operational costs and environmental pollution. Developments on crop adapted spraying for fungal control are highlighted in arable crop spraying. A plant-specific variable volume precision sprayer, guided by foliage shape and volume (canopy density sprayer canopy density sprayer (CDS); CDS canopy density sprayer (CDS)) was developed for bed-grown cropsbed-grown crops to apply fungicidesfungicides. Sensor selection to quantify crop canopycrop canopy and spray techniques to apply variable dose rates Variable rate technology are evaluated based on laboratory measurements. Based on the laboratory experience a prototype CDS canopy density sprayer (CDS) sprayer was built using either a Weed-ITWeed-IT ® or a GreenSeekerGreenSeeker ® sensor to detect plant place (fluorescence) or size (reflectance). Variable rate application Variable rate technology was either done with a pulse width modulation nozzle or a switchable four-nozzle body. Spray volume could be changed from 50 to 550 l ha-1 in 16 steps. Spray depositionSpray deposition, biological efficacybiological efficacy and agrochemical use reduction Pesticide use reduction were evaluated in a flower bulb and a potatopotato crop during field measurements using a prototype CDS canopy density sprayer (CDS) sprayer. Spray volume savings of a prototype plant-specific sprayer are shown to be more than 75% in early late blight (Phytophthora infestans Phytophthora infestans) control spraying in potatoes potato. In flower bulbs (lilylily) it was shown that in Botrytis blight Botrytis spp. control on average spray volume could be reduced by 45%. In a potato crop biological efficacy was maintained at the same good level as of a conventional spraying. In a flower bulb crop biological efficacy of the CDS canopy density sprayer (CDS) was lower than of conventional spraying, which means that spray strategy and dose algorithms need further research.