Journal of Cereal Science 28 (1998) 15–23 Article No. jc970181 Dependence of Wheat Dough Extensibility on Flour Sulphur and Nitrogen Concentrations and the Influence of Foliar-Applied Sulphur and Nitrogen Fertilisers P. S. Kettlewell*, M. W. Griffiths*, T. J. Hocking† and D. J. Wallington‡ *Harper Adams Agricultural College, Crop and Environment Research Centre, Newport, Shropshire, TF10 8NB, U.K., †University of Wolverhampton, School of Applied Sciences, Wulfruna Street, Wolverhampton, WV1 2SB, U.K. and ‡Weston Research Laboratories, Vanwall Road, Maidenhead, Berkshire, SL6 4UF, U.K. Received 29 November 1996 ABSTRACT Three field experiments on winter wheat from 1986 to 1988 tested the effect of late-season foliar- applied sulphur (S) and nitrogen (N) fertilisers on baking quality. Only the experiment in 1988 produced grain with an S concentration and N:S ratio that could be classified as deficient by the accepted thresholds. Grain or flour S concentration was increased slightly in 1986 and 1988 by foliar-applied S. Dough resistance was reduced slightly by applied S in 1986, but this effect was dependent on cultivar and whether foliar N was applied. There were no effects of the fertilisers on baking quality in 1987 or 1988. When data from all three experiments were combined and corrected for mean effects of year and cultivar, multiple regression showed that dough extensibility increased with both increasing flour S and N concentrations. This is the first report in the U.K. that dough extensibility is limited by flour S status of field-grown wheat, and these crops provide the earliest evidence in the U.K. of a relationship between a measure of baking quality and S status of flour.  1998 Academic Press Keywords: wheat, dough extensibility, flour S and N concentrations, foliar-applied S and N fertilisers. status of British wheat with some evidence of INTRODUCTION deficiency by the early 1990s 5 . The criteria used A deficiency of sulphur (S) is known to reduce in these surveys to define deficiency are based on baking quality of wheat flour 1,2 . In the U.K. in the thresholds for grain S concentration and N:S ratio 1980s, however, S fertilisers were not widely used in relation to yield 6 . Thresholds for defining de- in the main wheat-growing areas because S de- ficiency in relation to baking quality have not been position from the atmosphere provided a sufficient published, and there is no evidence that the same quantity of the nutrient to meet the relatively low thresholds apply to both yield and baking quality. crop demand of wheat 3 , and in a survey in the early Few studies of baking quality in relation to grain 1980s, wheat did not show evidence of deficiency 4 . or flour S status of field-grown wheat in the U.K. More recently, because atmospheric S deposition have been published. has declined, there has been a decrease in the S This paper describes three field experiments carried out from 1986 to 1988, between the times of the two surveys cited above, when declining S deposition was giving rise to concern that S Corresponding author: P. S. Kettlewell. 0733–5210/98/040015+09 $30.00/0  1998 Academic Press