A general joint action model for herbicide mixtures

✍ Scribed by Streibig, Jens C.; Kudsk, Per; Jensen, Jens E.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 231 KB
• Volume: 53
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199805)53:1<21::aid-ps748>3.0.co;2-l

✦ Synopsis

The assessment of mixture e †ects is usually done with isoboles which illustrate whether mixture e †ects are greater or smaller than would be expected on the basis of the individual activities of the herbicides. Under the assumption of similarity of response curves and by incorporating a function that can model the shape of isoboles, we can statistically test whether divergence from the Additive Dose Model (ADM) is signiÐcant. Two dose-response experiments with mixtures of either salt or ester formulations of MCPA and mecoprop-P and one experiment with tribenuron-methyl and mecoprop-P were analysed. Mixtures of tribenuron-methyl and a salt formulation of mecoprop-P showed antagonism. Mixtures of salt formulations of MCPA and mecoprop-P followed ADM, whilst ester formulations of the same compounds showed synergism. To get reliable estimates, the model requires mixture ratios covering the whole isobole 1998 SCI