VITAL TO CHECK OVER-WINTERED SEED BEFORE DRILLING

Following an unusually wet drilling season last year, many farmers have found themselves having to carry over unused winter cereal seed into this year, writes James Hill.  But with the planting period coming round again, it is vital to check its condition before drilling to ensure yields are not disappointing.

There is no reason why over-wintered wheat seed shouldn’t succeed the following year, but the extent of its success will depend on a number of factors – and drilling sub-standard seed which delivers compromised yields is certainly a counter-productive activity.

If stored correctly in cool-dry conditions, protected from frost, and in the original unopened bags if possible, there should be minimal loss of germination.  But if moisture, rodents or insects have affected the seed, germination levels could be reduced by 10%, 20%, or even more.

That is why having samples of carried-over winter seed germination tested is crucial.  This may be a cost – but it will be far more expensive to drill sub-standard seed and suffer catastrophic germination rates.  If tests show a potential reduction in germination rates for over-yeared seed, then seed rates can be adjusted accordingly to compensate.

Another factor which may affect potential germination rates will be any treatment that the seed has experienced – seed treatment labels often suggest that seed should be planted in the same season it is treated.  But in actual fact, conventional treatments such as a single purpose dressing, with or without take-all product Latitude (silthiofam) shouldn’t have a major detrimental effect if the seed is sown within 12 months of the original treatment.

That said, farmers can adjust their drilling order to give their over-yeared seed the best chance of thriving.  Using the over-wintered seed first can take advantage of kinder soil conditions, including warmer soil temperatures; newer seed which has been procured (and treated) in the current year is likely to be more robust, and can therefore be drilled into cooler soils, or in fields where take-all risk is higher, such as a second of third wheat.

One final important point about disposal of treated seed batch where a germination test has found it to be poor.  You can’t simply dump or burn this seed, as regulations stipulate it must be disposed of by a specialist contractor.  But this carries its own not insignificant cost, so the safest and most economical way of dealing with such seed is to plant it – even if that means using a very heavy seed rate to achieve the germination rate you require.