Assertion: chloropicrin's effect | /r/HasProperty | determined
Facets:
value: by measuring the time
type: MANNER
Source sentences:
text: Two methods were used to assess weed control: (1) prior to each hand-weeding event, weed densities were measured in two or four randomly selected, 0.25-square-meter samples per plot; and (2) the effect of treatments on hand-weeding was determined by measuring the time required for an experienced fieldworker to hand-weed one row 150 feet long.