2026 Volume 71 Issue 2 Pages 35-40
Information on the relationship between herbicide active ingredients and their weed control spectrum was collected from publicly available sources worldwide. Information on 867 weed species and 218 active ingredients was obtained. This information was quantified according to specific rules, compiled, and presented in a detailed table showing the weed control efficacy of each active ingredient against various weed species on a 10-point scale. Quick reference charts by crop type were also created for registered herbicide in Japan. Furthermore, when the efficacy of an active ingredient against a specific weed species is unknown, it is sometimes inferred that “if it is effective against a different species within the same genus, it is likely to be effective” or “if another active ingredient with the same HRAC code is effective, it is likely to be effective.” Based on the data collected in this survey, the average difference in evaluation scores fell below the random case with high probability, indicating this inference was generally reasonable, although variability remains.
