Annual weed distributions can be mapped with kriging

Summary The authenticity of weed distribution maps prepared by the geostatistical estimation method, kriging, was investigated. We concentrated on the total number of weed plants and the dominant weed genus Veronica spp. in a 2.1‐ha field of winter wheat. Different sampling distances were evaluated. Our analyses showed that kriging weed densities based on seedling counts collected in, 0.25.m 2 circles in a sampling grid of approximately 10 m × 10 m gave good agreement with actual observations. Reducing the sampling grid to 20 m × 30 m gave poor agreement. New sampling methods combined with positioning devices and injection sprayers are discussed with reference to site‐specific weed management.