| Tests | ADF | PP | KPSS | decision | |||
| Variables | t-statistic | Critical value (5%) | t-statistic | Critical value (5%) | t-statistic | Critical value (5%) | |
| Production cv | −6.316707 | −2.976263 | −15.76611 | −2.971853 | 0.351101 | 0.463000 | I (1) |
| Pluvio in ht | −4.007977 | −2.967767 | −3.907654 | −2.967776 | 0.138113 | 0.463000 | I (0) |
| Superficie | −5.609843 | −2.971853 | −5.774175 | −2.971853 | 0.260434 | 0.463000 | I (1) |