Sprayer boom optimization for bed-grown crops

For full-field grown arable crops, the application of evenly distributed sprays can be managed by selecting proper nozzles, nozzle spacings and sprayer boom height. For bed-grown crops, ideally the spray is applied evenly to the bed only, while no spray should be applied onto the paths in between the beds. This is a complicating factor that usually cannot be fulfilled easily. A model has been developed to help design the adequate set-ups of nozzles on a sprayer boom optimized for bed-grown crops. For this purpose, the spray distribution patterns of various single nozzles at different boom heights have been measured on a patternator. The model combines these spray patterns while varying nozzle types, nozzle spacings and the position and tilting of end nozzles. The model searches for set-ups that fulfil the requirements as defined by the user. Currently, the model focussed on the use of Lechler Varioselect fourfold nozzle bodies to find optimal solutions for beds with widths between 1.1 and 1.5 m and boom heights of 0.2 to 0.6 m above the crop, while being able to apply different dose rates depending on crop canopy height. Hundreds of thousands potential set-ups were simulated, but only relatively few meet the requirements. In the ideal set-up the application rate would be manageable by merely opening or closing the nozzles while assuring an even spray distribution on top of the bed. The model can be modified easily to use different nozzle types and boom set-ups, provided that the necessary spray patterns are available. Different user requirements can be implemented as well, for instance for band spraying or other user-definable spray distributions.