where b = slope, X = days after TIO, S = standard deviation, and 1 and 2 subscripts refer to treatments or varieties. Likewise, the TB temporal trend was fitted to a linear regression and the slope used as a tuber bulking rate approximation. Eqs. (3)–(5) were used to compare TB in the different treatments and varieties. These latter statistical analyses were run with R v3.0.1 software (R Core Team, 2013).