You may look at this article. https://www.jircas.go.jp/sites/default/files/publication/jarq/05-3-001-006_0.pdf

There is no fast way since you need to prepare the samples then measure absorbances :)

Grow in water solution and use a video.Regards

Introduce a hydroponic and grow maize. it will be easy for observation

The root activity was estimated following the TTC method (Comas

et al., 2000), and root activity was expressed as the

capacity of root deoxidization (mg g−1 h−1). In short, five hundred

milligrams (500 mg) of root sample were dipped in equal amounts (0.4%)

of TTC and phosphate buffer mixed solution (10 mL) followed by placing

in the dark for 1–3 h at 37 °C. After that, to stop the reaction of the

solution, we added 2 mL of 1 mol L−1 H2SO4. Then, the dipped roots

were blended, followed by transfer into a new tube containing ethyl

acetate cleaning solution (10 mL). The absorbance