3 November 1995

Mildew response saved beet growers millions

AN "UNPRECEDENTED" response to powdery mildew warnings saved sugar beet growers more than £8m this season, according to IACR-Brooms Barn.

By the end of August two-thirds of the UK crop was affected by the disease. It arrived particularly early – as soon as the third week in July in some areas, notes Dr Mike Asher.

But growers heeded warning notices so well that by the end of August 78% of the crop had been treated, mainly with an application of sulphur.

Corresponding yield lift

Using a "conservative" yield response of 5% to a single sulphur spray, he estimates the corresponding yield lift on the 112,000ha (277,000 acres) infected is more than 0.25m adjusted tonnes worth over £10m.

Net benefit, even allowing for the costs of treatment on the 78% area including £5/ha (£2/acre) for application, still exceeds £8m.

&#8226 Irrigation is unlikely to "spread" rhizomania, as previously reported (Arable, Oct 20), notes Dr Asher. The key is that it allows the disease to be detected more easily, he explains.