14 July 1995

Sulphurs to blame for light leaf spot

SULPHUR deficiency is the cause of rising light leaf spot levels in England, claims leading oilseed researcher Ewald Schnug of Braunschweig research station in Germany.

Indeed, sulphur deficiency is causing a wholesale downturn in the resistance of crops to stress of all kinds, including nutrition, diseases and pests, he suggested.

Sulphur metabolism within the plant has several steps that contribute to resistance to stress. One is the release of hydrogen sulphide gas, which helps protect plants from germinating disease spores. Another is the creation of an anti-oxidant which alleviates stress. Other intermediaries have also been shown to improve stress tolerance.

Dr Schnug said "sulphur induced resistance" is a goal worth striving for. Applying up to 80kg/ha of S would ensure healthy crops, with any wastage more than outweighed by the benefits, he said. Using sulphur as an aid to boosting crop productivity could also help cut chemical inputs. &#42