Contribution of nitrogen on industrial quality of oat grain components and the dynamics of relations with yield

Understanding the magnitude of contribution and relationships of industrial quality components to yield by nitrogen stimulation can drive strategies with benefits to the food industry. The objective of this study is to measure and interpret the contribution and relationship dynamics of the components of oat industrial quality with grain and industry yield by nitrogen stimulation, partitioning the correlation values in direct and indirect effects by path diagnosis, in proposing strategies that promote benefits to the food industry. The study was conducted from 2011 to 2016, in a randomized block design with four replications in 4x2 factorial for nitrogen rates (0, 30, 60 and 120 kg ha -1 ) and oat cultivars (Barbarasul and Brisasul) in separate environments soybean/oat and corn/oat succession system. The increase of nitrogen promoted greater change in the mass of caryopsis in soybean/oat system and the thousand grain mass and number of grains greater than 2 mm in corn/oat system, with a tendency of reduction. In soybean/oat system, grain and industry yields can be simultaneously incremented by direct increase via one thousand grain mass and indirect increase by caryopsis mass. In corn/oat system the grain yield does not show any relationship with industrial quality variables. However, the industral productivity is benefited by the increase of the number of grains larger than 2 mm. The management proposition in the improvement of the grain and industry productivity characteristics by nitrogen is dependent on the high succession and reduced N-residual release systems.