Crops and landscape plants are too often injured by inappropriate use of herbicides. The most common sources of herbicide injury are from off-target movement (spray drift, vapor drift, washing in surface waters), excess doses (due to poor calibration or just sloppy applications), contaminated soil or composts, carry-over residues from previous crops, or just choosing the wrong herbicide for the site / crop. The following information has been compiled to assist you in recognizing and diagnosing herbicide injury when it occurs.
Symptoms & Fact Sheets — Information and photographs of herbicide injury symptoms on ornamental plants and other horticultural crops
What To Do? — The most important thing to do is to get all the facts before drawing conclusions. Many factors may cause symptoms that mimic herbicide injury. Including how to conduct a bioassay for residues.
Herbicide Residues in Compost and Hay — a fact sheet from NCSU
Vegetables & Small Fruits — Wolfpack Weeds provides information on weed management systems for vegetable and fruit crops, and includes information on crop safety, herbicide development and efficiency, and photos of herbicide injury to vegetable and fruit crops.
Auxin Herbicide Drift on Horticultural Crops — Ohio State University and IPM. This web site has a series of fact sheets on the issues of dicamba and 2,4-D drift.
UC-IPM Herbicide Injury Symptoms — The University of California IPM web site created by Dr. Kassim Al-Khatib contains a searchable database for images of herbicide injury to many crop plants, as well as information about herbicide modes of action, preventing herbicide drift, and diagnosing herbicide injury.