Analysis of the tomato seed germination process under magnetostimulation using the Taguchi methodology

Abstract

This paper presents the application of the Taguchi methodology in the experimental design of the magnetic field exposure process for tomato seeds (Lycopersicon esculentum, Solanaceae) of a certified commercial variety, used as a model for intensive cultivation, by varying the magnetic field intensity and exposure time. The seeds were exposed to magnetic fields using a system of Helmholtz coils connected in series and powered by a direct current source. Due to the characteristics of this type of coil, quasi-uniform fields were generated in the central region of the experimental setup. The magnetic field intensities used were 400, 500, and 600 µT, and the exposure times were set at 60, 120, and 180 s. These variables (intensity and exposure time) act as independent variables of the system and are evaluated at three levels: low, medium, and high. Root length and germination rate index were chosen as response variables for the Taguchi design and optimized in a "bigger is better" manner for signal-to-noise ratio. The results revealed that exposing seeds to higher intensity fields for short periods of time produces beneficial results in the germination process.