A descriptive analysis by frequency counting, central trends measures and dispersion was made for those continuous type variables, as some of the variables inherent to laborers, and environmental and biological measurements. Continuous variables were transformed to normalize them. We also explored possible relationships between some variables and they were crossed by constructing contingency tables. We used the Student's t tests and chi square tests for the comparison of quantitative and categorical variables. Subsequently, we then performed a bivariate, stratified and logistic regression analysis. To compare results among laborers who worked in plots with GAP and traditional applications, the paired data test was used of Wilcoxon and Fisher for.
