Super S test on the way
Super S test on the way
NOT sure how badly your crops are suffering from sulphur deficiency?
A new, more reliable test to be launched in January could help pinpoint shortfalls in time to correct sulphur levels in the same season.
Based on IACR-Rothamsted work the diagnostic service from NRM Laboratories compares the amounts of sulphate and malate in young leaves.
The relatively simple technique should provide a much better guide to sulphur needs than measuring soil or plant concentrations or nitrogen:sulphur ratios, says Rothamsted researcher Steve McGrath.
"The problem with those is that they all change with time and the growth of crops. Results between labs can also be very variable."
Effective diagnosis is the key to avoiding low sulphur yield and quality losses, which are far more widespread than many growers realise, says Prof McGrath.
"The real problem is that you can lose a lot of yield without any visible symptoms."
The latest test has proved practical and very reliable in trials, irrespective of the time of sampling or growth stage. "It also works early in the season, which gives growers time enough to decide whether remedial action is needed."
The NRM service, which will require a representative 200-300g sample of foliage, will offer results, interpretation and an element of advice, says the firms Iain James. "We expect the cost will be around £10 a sample." *