Durum wheat grain yield and quality as affected by S rate under Mediterranean conditions

The decreased inputs of S from atmospheric acidic deposition, the use of low S-containing fertilisers, and the decrease of organic matter content in soil resulted in S deficiency in many agricultural regions of the world. Sulphur fertilisation significantly affects grain yield and protein composition of cereals, thus altering the technological quality of grain. Field experiments were conducted in central Italy in two subsequent seasons to investigate the effects of N and S application on five commercial wheat cultivars known to differ in yield potential and grain N content. Fertiliser treatments were two levels of N fertiliser (120 kg N ha(-1) and 180 kg N ha(-1)) and three levels of S fertiliser (not applied, 60 kg S ha(-1). and 120 kg S ha(-1)). Analyzed characters were dry weight and N and S uptake of grain and vegetative plant part, and grain quality characters. Variations in weather pattern - and especially in rainfall - between years significantly influenced grain yield and N and S content of grain, but did not affect quality parameters. Nitrogen and S application also significantly affected grain yield and the quality characteristics W, P/L, dry gluten and SDS. although no interactive effect between treatments was observed. The highest protein content and Win grain was obtained with the combination of the highest fertiliser rates: 180 kg N ha(-1) and 120 kg S ha(-1). Genotypes differed for yield stability between years, in that grain production was decreased in the driest year only in the varieties Claudio and Creso, but they responded similarly to N and S fertilisation. Genotypes differed also for protein concentration and quality parameters, and, on average, the varieties Duilio, Simeto and Svevo gave better performances. Differences in grain quality parameters were maintained through years, indicating that these traits are under strong genetic control. (C) 2011 Elsevier B.V. All rights reserved.