Herbicide Damage from Dugout Water (April 2005)

 poinsettia tips











Picloram herbicide damage to poinsettia plants. These plants received dugout water which was contaminated with 0.2 ppb of Picloram.

Fuschias damaged by herbicide











Fuchsia stock plants damaged due to Picloram. Look for abnormal leaf twisting.

tomatoes damaged by herbicide











Tomato plants damaged due to Picloram.


A dugout water supply was contaminated with a herbicide commonly called Tordon, with active ingredient Picloram. The county sprayed the ditches to get rid of weeds and the rain brought all the herbicide to the dugout. This happened in spite of the fact that the county had all the information about not spraying the ditches around the greenhouse. When growers saw the twisting of new poinsettia growth he had the water checked out and it came back with a herbicide residue of 0.2 PPB (parts per billion). Parts per billion seems like a small amount, but plants use large quantities of water and the herbicide stays in the tissue causing these symptoms. Here is what you should do under such situation:

  • Find out the source of contamination. It could be drift from spraying by neighbours or county spraying the ditches or accidentally you sprayed a herbicide around your dugout.
  • Notify the people concerned because there may be insurance claims involved.
  • Get an analysis done of water and of plant tissue.
  • Record all data, like number of plants, extent of damage, important dates, what actions you took.
  • Seek a specialist's opinion about the potential damage. The plants may not recover.
  • Install activated charcoal filters so that incoming water can be treated.
  • Some plant recovery is possible by applying activated charcoal to pots. Apply 2-3 ounces/pot.