Mechelle's main area of research is the identification and evaluation of herbicide resistant weed populations in Western Australian cropping regions. This includes survey work to evaluate the frequency and distribution of herbicide resistance in a number of crop weeds (wild oat, ryegrass, brome grass, barley grass, conyza and wild radish) in the Western Australian grain belt. Other surveys and research includes; farmer surveys on the extent of weed seed contamination present in crop seed sown in Western Australian grain-belt farming systems, seed dormancy in annual ryegrass and the characterisation of herbicide resistant weed populations where resistance is rare e.g. glyphosate resistance in ryegrass.

Surveys to establish the frequency and distribution of herbicide resistance in major weed species across the WA grainbelt. Monitoring glyphosate resistance in annual ryegrass. Seed dormancy in annual ryegrass. Weed seed contamination in farmer saved crop seed.