Use this plant measurement when samples, dry- or fresh-mass basis, image threshold, geometry, instrument calibration, and treatment timing follow one consistent protocol.

Absorbance at 480 nm

Absorbance at 480 nanometers; must not be negative.

Leaf fresh mass

Leaf fresh mass in grams; must be greater than zero.

The implementation follows this calculation rule: Estimate total carotenoid content in micrograms per gram of leaf fresh mass as the absorbance at 480 nanometers times four divided by the fresh mass, following the documented Arnon-proxy extinction scaling.

Carotenoid content

Carotenoid content in micrograms per gram of leaf fresh mass.

Pigment proxies, canopy metrics, tissue density, and leakage indices are method-dependent. Species, developmental stage, hydration, illumination, extraction efficiency, sensor angle, and environmental conditions can confound comparisons. The output is explicitly an estimate or proxy; preserve that label when reporting it.

Pair the proxy with calibrated chemical analysis, destructive biomass sampling, or repeated field measurements where practical. Report environmental conditions and whether values use fresh mass, dry mass, area, or volume.

• Anthocyanin Content

  Compute anthocyanin content in micrograms per gram of dry mass as the corrected absorbance divided by the dry mass times an extinction scale factor that defaults to one hundred; apply any baseline correction to the absorbance upstream before passing it in.

• SPAD To Chlorophyll

  Estimate chlorophyll content from a SPAD reading with the documented linear approximation chlorophyll = SPAD value times conversion factor, where the factor defaults to 0.4.

• Crop Growth Rate

  Compute crop growth rate in grams per square metre of ground per day as standing dry mass gain divided by ground area times elapsed days.