entity scale_of Collect all roots from a standard-size excavation of 20 x 20 x 20 cm extending outwards from the corm of the plant. Take only roots from the selected plant. Divide the collected roots into two categories: dead roots, functional roots. Dead roots are completely rotten or shrivelled whereas functional roots show at least some healthy tissue. From the functional roots, randomly select five primary roots that are at least 10 cm, and reduce their length to 10 cm. Where root knot nematode galls are present, determine the extent of the galling using the scale. Nematode root knot galling extent - estimation attribute acronym method_of variable_of