Cause-and-Effect Relationships in Dry Beans Cultivars Yield Components Under Crop-Livestock System Management

In order to identify the contribution of yield components to the final yield of dry beans, two widely adopted cultivars (IAC Milênio, and IPR Tuiuiú) were evaluated under nitrogen fertilization levels (0, 50, 100 and 150 kg N ha-1) in a crop-livestock system. Experiments were conducted under a randomized complete block with three replications design during two years (2016 and 2017) which were split in two cropping phases. A subplot factorial scheme of grazing heights by nitrogen fertilization (grains crops or pasture) was used. Dry beans crops were fertilized during the summer and yield components evaluated along with yield measurements. Descriptive and Pearson’s correlation coefficient analyses were performed and followed by path analysis to explain the interrelationship between yield components (explanatory traits) and yield (main trait). For IAC Milenio in 2016 cultivated as a second crop the main trait influencing yield the number of seeds per plant through direct and indirect effect of other traits, regardless of the topdressing nitrogen level applied. In 2017, a greater number of significant correlations was found for the IPR Tuiuiú cultivar. The number of pods per plant was the trait that affected yield most all nitrogen levels.