HALF OF fields at risk from wheat bulb fly in eastern England were above the damage threshold, according to results from a Home Grown Cereals Authority (HGCA) survey.

The autumn 2005 survey found that 50% of fields exceeded 250 eggs/m2 (2.5 million eggs/ha) and there may be an economic benefit from applying a seed treatment to late-sown crops in these circumstances.

In eastern England, high egg counts were recorded following leeks, onions, potatoes and sugar beet, while a lower count was recorded after vining peas.

In northern England, 42% of fields sampled contained moderate egg populations (1-2.5m eggs/ha), which would justify seed treatment on November or December-drilled crops, the survey also found.

A full copy of the report is available at www.hgca.com and the HGCA is looking for feedback from growers to find out how useful the information has been.

If feedback is positive, it is planned to continue the survey for another two seasons.