Simba contains 100 g/ L mesotrione and is a fine, homogeneous, beige-coloured suspension with a characteristic odour.
It is a systemic herbicide, which acts by inhibiting the enzyme 4-HPPD. The active substance belongs to the triketone class of chemicals and has a different mode of action than broadleaf weed control herbicides. It inhibits amino acid conversion and carotenoid biosynthesis, resulting in the destruction of chlorophyll (which is not protected) by sunlight. The symptom known as leaf blight occurs. The product is absorbed mainly through the leaves, but also through the roots and translocated throughout the plant via the xylem and phloem.
Simba is an early postemergence herbicide used in maize to control important annual dicotyledonous and some annual monocotyledonous weeds. For maximum effect the weeds must be small, in the active growth stage, the weather must be sufficiently warm, and moisture adequate. On dry soils the control effect may be diminished. It is not recommended to apply the treatment when the weeds or the maize crop are wet. Application to seed corn is not recommended.
