Results of an experiment to investigate the relationship between the
early growth of safflower plants and the concentration of glyphosate
(a weed-killer) introduced into the water-supply.

The four columns correspond to:
   glyph: glyphosate concentration in water supply (ppm)
   water: 1 if glyphosate added to distilled water,
          2 if glyphosate added to tap water.
     rep: 1, 2 or 3 corresponding to replicate (start-dates 25.03.83, 
          28.03.83 and 05.04.83, note that control runs with zero 
          glyphosate were also duplicated on each date)
    root: total root length of 15 safflower plants