Abstract: 【Objective】To grope assessment methods in allelopathic potential of crops germplasms, and analyze the comprehensive allelopathic potential of crop cultivars, and in view of theory assay the whole allelopathic potential in winter wheat accessions from the Loess Plateau. 【Method】To build system-engineering model and evaluate the comprehensive allelopathic potential of crop cultivars, and propose the quantification method of the whole allelopathic potential in crop accessions was conducted in the present study. Allelopathic potential in a whole level of four winter wheat varieties from the Loess Plateau was estimated in view of system theory and compared.【Result】The model assessed allelopathic potential in different parts of the plants from the time that wheat turned green in the spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order: Xiaoyan No 22 > Ningdong No 1 > Fengchan No 3 > Bima No 1. 【Conclusion】This system engineering evaluation method allows for the reasonable assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.

Key words: Systemic engineering principle, Evaluation of crop allelopathic potential, Synergic indices of allelopathic potential, Comprehensive index of allelopathic potential, Genetic breeding of allelopathic crop accession