ANALYSIS of seed collected from UK wheat crops prior to harvest has confirmed that four out of five samples are already infected with at least one of the two major crop establishment diseases.

The study was conducted by Syngenta on 55 seed lots using PCR analysis, a technique which shows disease presence based on the detection of fungal DNA.

Results confirmed that 80pc of samples were infected with either fusarium, microdochium or both. These diseases can slash yields through poor crop establishment or increased winter kill by up to 20pc.

Sixty four per cent of samples had fusarium infection, either alone or combined with microdochium, while 58pc had infections of microdochium.

And although levels of infection were lower than last year, when 91pc of samples had fusarium and 95pc microdochium, they still underlined the importance of applying an effective seed treatment, Iain Hamilton, Syngenta technical manager said.

"Fusarium and microdochium are, without doubt, the main disease threats to crop establishment in autumn and effective seed treatment is the only way of protecting the emerging crop against seed and soil-borne infections," he said.

"As part of the monitoring, we also compared levels of infection in samples where different seed treatments had been used when crops were drilled."

Comparing findings, Mr Hamilton calculates that 31pc fewer samples had infections of fusarium where crops had been treated with Beret Gold (fludioxonil) seed treatment compared with other seed dressings. Similarly, 35pc fewer had infections of microdochium after Beret Gold.

"The message this year is that, despite the relatively dry June, which doesn't normally favour seed-borne infection, both diseases must be considered," he said.

"As well as controlling fusarium and microdochium, Beret Gold also controls seed and soil-borne bunt. It forms a protective zone around the emerging seedling. Seed should be tested and, if necessary, treated," he said.

As with testing last year, results also showed little difference in levels of infection between varieties - though fusarium incidence was lowest on the 11 Claire samples tested (36pc of samples infected) and the incidence of microdochium lowest on Access (40pc of samples).