26 November 1999

Computerised advice reduces herbicide use

By Charles Abel

COMPUTERISED advice to aid herbicide decision making is helping Danish growers reduce herbicide use without cutting weed control.

Not only does the system consider the need to spray and assess the level of control needed for each species, it also chooses the right herbicide and dose combination for the crop, variety, growth stage and local weather conditions.

Crop value and input price are considered and results presented as a least cost or most environmentally friendly option.

"We know farmers need to spray their crops, so controlled doses rather than a spray or no spray response seemed the best way to respond to government policies designed to reduce pesticide usage," says Per Kudsk of the Danish Institute of Agricultural Science at Flakkebjerg.

Over 100 validation trials for each of the eleven crops the programme is designed for have shown dose reductions of up to 85%, with an average of 50% in cereals. "In all cases weed control was acceptable and yield greater or equal to a standard approach," comments colleague Per Rydahl.

So far the package is for cereals only. A sugar beet system is planned.

Cost is £200 plus £40 for annual updating, with 1800 of Denmarks cereal farmers currently using the PC-based package. Putting it on the internet is expected to boost uptake further.

&#8226 Efforts to develop a similar system for the UK are progressing, with the factors influencing weed control now being quantified, says Alister Blair of IACR Rothamsted. &#42