Task: Class Definition Understanding (ontology: Food_Agriculture/Crop_Ontology)

Which of the following definitions best describes 'Root biomass - Method'?

A. Measuring total roots weight.
B. Weighing of hundred kernels (seeds).
C. SCMR [SPAD (Soil Plant Analytical Development) Chlorophyll Meter Readings] taken in the morning 120 days following germination using the first expanded leaves of 4 lateral branches on each plant.
D. SCMR (SPAD (Soil Plant Analytical Development) Chlorophyll Meter Readings). Unitless measurement, averaged over 4 leaflets of the most fully expanded leaf in the main stem.

Answer: Measuring total roots weight.