Measures that describe weed spatial patterns at different levels of resolution and their applications for patch spraying of weeds

Abstract

If weeds occur in aggregated spatial patterns, it is possible to reduce herbicide use by spraying only weed patches. The reduction in herbicide use will then depend on the spatial resolution of the patch sprayer and the weed‐free area at that level of resolution. Three distance measures are presented that describe the weed spatial pattern at different levels of resolution. They give information on aspects of pattern that are relevant to patch spraying. The distance measures were applied to a spatial pattern of Galium aparine L. seedlings recorded in an area of 18.0 m × 32.4 m. In this area, the herbicide use of an idealized patch sprayer that detects and sprays all weeds with a spatial resolution of 1.0 m would be 41% of the amount required for a whole‐field application. Spraying with a finer spatial resolution of 0.5 m would give a further 26% reduction in herbicide use.