Carthamus lanatus

Seed germination is stimulated by red light.[5] This means that germination is most likely in areas with little vegetation or pasture cover, e.g. when an area has been overgrazed. Seeds also require specific temperature cues and water, which means that most seeds germinate in Autumn (Fall). There are more C. lanatus seeds in the soil in Australian pastures than in similar French pastures, probably because there are more seed predators capable of removing seeds of this size in France than in Australia.[4] Many C. lanatus seeds are dormant (will not germinate, even in ideal conditions), and seedbanks decrease by approximately 70-74% per year if no seed is added.[6]

This plant can be controlled using a range of herbicides.[7] Several biological control options have been investigated for Australia, including classical biological control, although finding an insect or fungus that will not also attack safflower has proven difficult. A rosette-feeding fly Botanophila turcica shows some promise.[8] The potential for using pathogens already present in Australia has also been investigated.[9]

In pastures, good pasture cover in Autumn will reduce germination,[10] suggesting that pastures should be managed to reduce grazing pressure over summer, and increase the cover from summer-growing perennial grasses. Population models suggest that strategic grazing may be one of the most effective long-term control options for infested pastures.[11]