Patent ID: 8216975

Claim:
A method of labelling soya varieties as to their suitability as a subsequent crop to maize when weed control in that maize crop has been carried out using HPPD inhibitor herbicides, wherein: a) in a first step, a reference soya variety is selected which, when grown as a subsequent crop to maize wherein weed control has been carried out using HPPD inhibitor herbicides and wherein soil residues of the HPPD inhibitor herbicides exist at the time the soya variety is subsequently grown, exhibits from 5 to 20% phytotoxicity with respect to those HPPD inhibitor herbicide soil residues; b) in a second step, the phytotoxicity of soya varieties when grown in the same manner as the reference variety in the first step is determined in relation to that reference soya variety in the form of a factor; and c) in a third step, said soya varieties are labelled with said factor.