Nitrogen management in the relationships between oat inflorescence components and productivity

ABSTRACT Among oat inflorescence components there are different magnitudes of contribution to expression of grain and industrial productivity by nitrogen stimulation. Thus, it was proposed to size and interpret the contribution and dynamics of the relationships of oat inflorescence components with grain and industrial yield by N-fertilizer stimulation, partitioning correlation values into direct and indirect effects by path diagnosis, strengthened by the joint analysis of different agricultural years. The study was carried out from 2011 to 2016, in the municipality of Augusto Pestana, RS, Brazil, in a randomized block design with four repetitions in a 4 x 2 factorial scheme for nitrogen doses (0, 30, 60 and 120 kg ha-1), using oat cultivars (Barbarasul and Brisasul) in soybean/oat and corn/oat systems. In the soybean/oat system, the mass and the number of panicle spikelets and the mass of panicle grains, contributed more to promoting changes by the increase of nitrogen. In the corn/oat system, the variables with the highest contribution are the mass and the number of panicle spikelets. The increase in panicle grain mass and in panicle harvest index increases grain yield, however, together with the number of panicle grains, they reduce industrial productivity, regardless of the cultivation system.