Sensor-based assessment of herbicide effects

• Published in: Weed research 2014-06, Vol.54 (3), p.223-233
• Main Authors: Streibig, J C, Rasmussen, J, Andújar, D, Andreasen, C, Berge, T W, Chachalis, D, Dittmann, T, Gerhards, R, Giselsson, T M, Hamouz, P, Jaeger-Hansen, C, Jensen, K, Jørgensen, R N, Keller, M, Laursen, M, Midtiby, H S, Nielsen, J, Müller, S, Nordmeyer, H, Peteinatos, G, Papadopoulos, A, Svensgaard, J, Weis, M, Christensen, S
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; barley; Biological and medical sciences; Chemical control; Fundamental and applied biological sciences. Psychology; glyphosate; image analysis; logarithmic sprayer; oilseed rape; Parasitic plants. Weeds; Phytopathology. Animal pests. Plant and forest protection; tribenuron-methyl; Weeds
• ISSN: 0043-1737; 1365-3180
• DOI: 10.1111/wre.12079

Summary Non‐destructive assessment of herbicide effects may be able to support integrated weed management. To test whether effects of herbicides on canopy variables could be detected by sensors, two crops were used as models and treated with herbicides at BBCH 20 using a logarithmic sprayer. Twelve days after spraying at BBCH 25 and 42 days after sowing, nine sensor systems scanned a spring barley and an oilseed rape field experiment sown at different densities and sprayed with increasing field rates of glyphosate and tribenuron‐methyl. The objective was to compare ED50s for crops and weeds derived by the different sensors in relation to crop density and herbicides. Although sensors were not directly developed to detect herbicide symptoms, they all detected changes in canopy colours or height and crop density. Generally ED50s showed the same pattern in response to crop density within herbicide, but there were marked differences between barley and oilseed rape. We suggest that the results of comparing the various sensor outputs could become a stepping stone to future standardisation for the benefit of the research and development of sensors that will detect herbicide effect on crops and weeds, particularly at the most vulnerable stages of development of the canopy.