βvalues obtained by linear regression models of morpho-physiological and biochemical variables as novel drought stress estimators in Capsicum annuumvarieties

•Morpho-physiological and biochemical linear models as drought stress estimators.•β-values of photosynthesis is a good estimator for drought stress classification.•Transpiration, photosynthesis, proline, and SOD could describe drought stress.•NDVIcould help detect drought stress, especially in the early stages of growth.