1 March 2002

His masters mapping voice

By Mike Williams

MAPPING areas of weed infestation, regarded as one of the biggest barriers to the adoption of patch spraying, has been simplified thanks to new voice recognition equipment that responds to verbal instructions from the operator.

Existing mapping techniques use data recorded manually on a keypad, but pressing the correct key at exactly the right moment is not easy while bouncing across a field on an ATV or tractor, causing the operator to drive slowly or stop to record the data.

New voice recognition software, developed jointly by the SRI and IACR at Rothamsted, recognises the names of weeds likely to be involved in patch spraying operations.

The name is spoken once as the operator enters a weed infested patch and again when moving out of the patch. This data is used by the computer to produce a map that can control the patch sprayer.

In tests at the SRI, the equipment was mounted on an ATV carrying a GPS link. Weed mapping could be carried out at 5mph, which produced a 3ha/hour work rate with the operator identifying weed patches across a 6m width.

Other developments to make patch spraying more user-friendly include research at the SRI and IACR to produce guidelines for the frequency of weed mapping.

The location of areas of infestation are reasonably stable for the majority of the problem weeds.

The principle movement is 2-3m/year in the direction of the first post-harvest cultivation as seeds are moved with the soil or on the tractor wheels.

Creating a new field map every three years should be sufficient for effective patch spraying.

The principle exceptions are wild oats and sterile brome where the spread can be much wider due to seeds temporarily caught up in the combine and released again later. A new map is needed every other year where these weeds are a problem. &#42

Weed mapping on an ATV equipped with the new voice recognition technology.