A greater number of wheat samples have tested positive for bunt, prompting NIAB TAG to warn growers using farm-saved seed.

“This year the NIAB Labtest service has, so far, seen a greater than usual number of wheat samples with bunt contamination, with spores in just under half of all seed samples received,” said NIAB TAG pathologist Jane Thomas.

“While this is more than normal, it’s not exceptional as most are either at, or below, the one spore per seed threshold, above which treatment is always recommended. However, what is concerning is that that 14% of samples have been above the treatment threshold,” warns Dr Thomas.

She believes caution is needed – using bunt infected seed will lead to serious losses next year. “Any seed which is being considered for use untreated should be tested and treatment applied if above the threshold of one spore per seed.

“If the seed cannot be treated it should not be used for further production. Ensure seed bulks are sampled effectively by checking the HGCA guidelines ‘Sampling wheat seed for seed-borne diseases – TS72’,” advises Dr Thomas.