Influence of durum wheat-faba bean intercrop on specific quality traits of organic durum wheat

Abstract

To identify agronomic practices able to increase the nitrogen (N) availability for durum wheat under organic farming, the temporary intercropping with faba bean (Vicia faba L. var. minor Beck.) was tested in a multiyear experimental trial. The accumulation of total protein and specific protein fractions in the grain of eight Italian durum wheat cultivars grown as sole crop (SC) or intercropped with legume until durum wheat shooting were compared. Gluten quality was also examined. Analysis of variance indicated that gluten quality, total protein concentration, and monomeric and polymeric protein amounts were significantly higher in intercrops than in SCs whereas the grain yield was significantly higher in the SC. Significant cultivar × treatment interactions were observed for most of the tested parameters. PCA allowed the visualization of the genotypes able to use the higher N availability coming from the temporary intercropping to achieve the grain protein concentration of 14.1% dry matter, the threshold considered suitable by the industry for producing high quality pasta. In addition, one such genotypes also showed good grain yield, with the highest values in the temporary intercrop. The results suggested that the durum wheat-faba bean temporary intercropping could be an agronomic strategy for improving the grain quality of the cereal under organic management and, as a consequence, it may be expected to have a positive impact on the durum wheat end-product quality.