14 March 1996

Post-emergence killer safe for most varieties

MAIZE growers have a new post-emergence chemical to control grass and broad-leaved weeds this season.

Titus (rimsulfuron), is a sulfonylurea herbicide in a dry-flowable formulation. It is safe to use on most varieties, says DuPont product manager, John Austin. "The most notable exception is Hudson, but about 75% of the UK area is included on the positive variety list."

The chemical can be applied up to the six leaves-expanded crop growth stage. A 50g/ha rate plus non-ionic wetter (for example, from Agral or Citowett) will control couch grass from three leaves to 15cm (6in) tall, and annual grass weeds, including blackgrass, wild oats, ryegrass, meadow grasses and volunteer cereals, from three leaves to one tiller.

That rate will also kill several types of broad-leaved weeds, including cleavers, chickweed, volunteer oilseed rape and may-weeds. But 40g/ha of Titus and 1 litre/ha of Bromotril P (bromoxynil) offers as good control and also kill polygonums.

The mix will also give some grass weed control, though Mr Austin recommends the same rate of Titus plus 0.5 litres/ha of atrazine and wetter where both types of weeds are present.

Last years price was £95 for a 120g pack. No prices are available for this season, but Mr Austin says it will remain competitive. &#42