17 August 2001

25% germination failure

ABOUT one-quarter of all over-yeared wheat seed tested by NIABs advisory service is failing to meet the minimum 85% germination, which is the standard for certified material.

Although two-thirds of the 100 wheat samples seen so far have achieved at least 95% germination, the cost of the Labtest service is easily justified to avoid poor establishment, says Juno McKee.

Many factors, including original viability, moisture, temperature during storage and chemical dressings can affect germination. None stands out as being a key cause of this years low figures.

For growers with untreated seed, the quick tetrazolium test, costing £35 a sample, can indicate potential germination within a day. But it does not detect dormancy or any potential field effects from seed dressings, she warns.

"For over-yeared, chemically-treated seed a full germination test is the most suitable option." Including a thousand seed weight assessment to permit suitable seed rate adjustments. This costs £42 a sample but takes five to seven days.

"While most seed has retained good germination potential, we have seen sufficient poor results to underline the value of testing." &#42

STOREDWHEATSEED

&#8226 25% of samples below minimum germination.

&#8226 Risk of poor establishment.

&#8226 Full germination test advised.

&#8226 Seed rate adjustments required.