Crunch time for effective weed control
Sort out these villains by the middle of the month or they'll start to be a threat to yields
Published 12/04/2011 | 05:00
As many growers will testify, the coldest year in the past 40 -- 2010 -- had some effects on all crops, not least winter oats.
Weeds are also subjected to the same conditions so there was a large winter kill of weeds, especially annual meadow grass.
At this stage of the year, most crops have received at least one herbicide, ranging from DFF + IPU or PDM + IPU or similar in the autumn. Spring applications ranged from an application of IPU as a holding strategy with a follow-up of a Fluroxypyr, to the likes of Cougar and Alistair.
Competitive weeds not controlled so far should be sorted by the middle of the month as competition by weeds, such as cleavers, after this stage will knock yield.
In the northeast, some growers are increasingly relying on Pacifica to do the heavy lifting of weed control in the spring. Pacifica offers excellent control of a broad range of weeds, including sterile brome, wild oats, annual meadow grass and soft broad-leaved weeds. However, it tends to be weaker on cleavers, bindweeds and knotgrass. In addition, a strategy that relies heavily on an ALS-type product to control all weeds will increase the likelihood of building ALS-resistant populations in the field.
If this happens, weed control will then be more expensive in these fields. Use a herbicide with another mode of action before or after Pacifica, to reduce the risk of building up ALS-resistant weeds.
Broadway Star is new to the market this year. This herbicide will prove a useful addition to winter wheat weed control. The product boasts an impressive array of weeds that it will control, including rye-grass, soft brome, sterile brome, wild oats, cleavers, poppy, pansy, common field speedwell, ivy-leaved speedwell, charlock, volunteer rape and mayweed. The addition of an adjuvant, such as BioSyl, is recommended.
Broadway Star can be applied up to growth stage 32. Its only obvious weakness is the lack of annual meadow grass control and the fact it is classed in the ALS inhibitor stable of herbicides, which may be an issue with certain resistant varieties of weeds.