Seasonal advice to get the best from Kerb Flo 500

UK - October 30, 2012

Dow AgroSciences are issuing Kerb Weather data reports on a weekly basis to guide farmers and advisors when best to apply this herbicide in oilseed rape. It is critical in oilseed rape that top class advice (not just information) is given by agronomists and then it can be acted upon in conjunction with their expertise to get the best possible weed control using Kerb Flo 500 this autumn, says David Roberts of Dow AgroSciences.  “Optimum weed control will be vital this season in order to maximise yield potential and the autumn is the time to get it right.”

This week’s Weather Bulletin acknowledges the rain and foggy conditions mean that soils are likely to remain saturated. It also reports that soil temperatures have declined to about 11° to 12°C in the East and South but in the North of England are now below 10°C, a temperature that is critical to maximise Kerb Flo 500 activity. In reality saturated soils could mean travelling on the field may be difficult however. Any decision to begin applying Kerb Flo 500 to soils that have cooled must only be made after taking all necessary precautions to avoid contaminating surface waters.

In order to maximise the efficacy of Kerb Flo 500, it is recommended that applications are made when soil temperatures fall to below 10°C and are falling and when the soil moisture deficit is below 50mm and falling.  “Meeting these criteria will enhance the longevity of propyzamide in the soil and give improved residual control, particularly important this year when black-grass germination is expected to be prolonged. However care must be taken to avoid any risk of contamination to water and importantly all aspects of good Stewardship must be applied,” says David.

To monitor local conditions as they progress over the season, growers and advisors can see the latest Kerb Weather Data in their region by going to the Dow AgroSciences web site http://www.dowagro.com/uk/oilseed/kerb.htm.  More Kerb Weather Data will be supplied as the season progresses.

David Roberts points out that if spray days are limited this autumn, growers can maximise sprayer efficacy with the new Kerb Flo 500 formulation.  “This new formulation comes in 10 litre packs with self-seal caps and no foils, making it easier and quicker to use, minimising spillages and lowering the risk of point source contamination. The new top dose rate is 1.7 l/ha, so there are fewer packs to open, rinse and clean and fewer packs to dispose of, making the whole spray operation quicker.”

He also points out that Dow AgroSciences support a range of herbicide and fungicide tank-mixes to speed up spray operations. “Extensive trials data shows that in high populations of difficult black-grass, superior control can be achieved by adding a fop/dim graminicide such as cycloxydim (Laser) to Kerb Flo 500 (even when fop/dim resistance is known to be present) over and above a carbetamide/propyzamide sequence.”

With Phoma and downy mildew a concern and many crops yet to receive their planned fungicides, Kerb Flo 500 is physically compatible with many fungicides including difenconazole (Plover), prothioconazole (Proline), flusilazole + carbendazim (Punch C) and flusilazole (Sanction), with the later two products sprayable under continuous agitation). Although many such mixes have been tested and shown to be physically compatible, Dow AgroSciences does not support Kerb Flo 500 plus graminicide plus fungicide mixes for crop safety reasons, due to the potential for enhanced PGR effects from the fungicide and so use is at growers’ own risk.

Kerb Flo 500 contains 500 g/litre propyzamide formulated as a suspension concentrate and packed in a new non-foil sealed 10 litre pack. In oilseed rape it is recommended at a dose rate of 1.7 l/ha for difficult black-grass situations in a minimum water volume of 200 L/ha. It is recommended at 1.0 l/ha or 1.4 l/ha to control annual meadow-grass, rye-grass, wild-oats, brome and volunteer cereals and a wide range of broad-leaved weeds including chickweed and speedwells. In oilseed rape Kerb Flo 500 has a wide window of application of four months, from the 1st of October through to the end of January.