Performance evaluation of an automated detection and control system for volunteer potatoes in sugar beet fields

Incomplete control of volunteer potato plants causes a high environmental load through increased crop protection chemical usage in potato cropping. A joint effort of industry, policy makers and science initiated a four year scientific project on detection and control of volunteer potato plants. A proof-of-principle machine for automated detection and control of volunteer potato plants in sugar beet fields has been tested in experimental fields. Machine vision-based detection at 100 mm2 precision is combined with a micro-sprayer with five needles and a working width of 0.2 m. The accuracy of the system was ±14 mm in longitudinal direction and ±7.5 mm in transverse direction. The main error source was the variability in micro-sprayer droplet velocity that caused longitudinal errors. However, 77% of volunteer plants with a size larger than 1200 mm2 were successfully controlled at machine speeds up to 0.8 m s−1. Within the crop row, glyphosate was applied on weed potato plants and this resulted in the unwanted death of up to 1.0% of sugar beet plants.