27 July 2001

Blight profile boon

COMPUTER profiling of blight risk can help protect potato crops and has cut control costs from an estimated £70/ha (£28.33/acre) to £21/ha (£8.50/acre) in BPC reference crops.

But growers must still use common sense to make final judgements over spray programmes, warns consultant, Howard Hinds, of DMA Crop Consultants, which manages the Plant-Plus blight forecasting project for BPCs reference crops. Profiling is a useful tool but tools should help growers make decisions, not replace their thinking altogether, he says.

The software uses agronomic data, weather forecasts and local sources of blight infection to assess crop risk and then formulates a spray programme.

Once treatments have been applied the model assumes blight risk has diminished to zero, but compensates by making no allowance for carry-over protection.

Across all four BPC reference crop sites, the Plant-Plus system is showing savings in spray bills, compared with conventional practice. For the Harper Adams site, savings are estimated at £49/ha (£20/acre). &#42