Optimisation of tetrazolium concentration and immersion time in the viability test of Swietenia macrophylla seeds by using Response Surface Methodology

The aim of this study was to optimise tetrazolium concentration and immersion time in the viability test of S. macrophylla seeds by using Response Surface Methodology (RSM). For this, a RSM Central Composite Design (CCD), type 23 was applied. The quantification of viable and non-viable seed germs was performed using the interpretation of topological patterns. The viability of the seed expressed as a percentage was selected as a response variable whilst the tetrazolium concentration and immersion time were independent factors. The quadratic polynomial model of the four evaluated aspects was best adjusted with 0.99 and 0.93 for the coefficients R2 and Predicted-R2, respectively. Using ANOVA, it was demonstrated that only immersion had a significant effect. The optimisation study showed that it is possible to achieve values of viability above 90% at low tetrazolium concentrations (0.05%) using immersion times between 75 and 90 minutes.