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Take care with Bunt this season

13 September 2010

Bunt in the wheat earCheck farm-saved wheat seed for bunt contamination as results from a national seed-testing service suggests there could be cause for concern.

“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,” says NIAB pathologist Jane Thomas.

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

Dr Jane ThomasNIAB Labtest samples are dominated by farm-saved seed, including organic and conventional wheat seed that growers may intend to sow untreated. Dr Thomas advises that the samples seen may not represent a true survey of all farm-saved seed and the overall picture may be very different. However, she believes the results emphasise that 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.

Untreated seed can be used safely for grain production, but the key rules are:

• sample properly;
• always have appropriate health tests;
• be prepared to treat or discard seed if the test results indicate above threshold levels for any disease; and
• avoid using more than one generation of untreated seed.

For further information contact:
Dr Jane Thomas, Head of Field Crops Research, NIAB
T: 01223 342251
E: jane.thomas@niab.com

Issued by:
Ros Lloyd, FrontFoot Communications
T: 01487 831425
M: 07711 568164
E: ros.lloyd@frontfoot.uk.com