Glyphosate injury on tomato
Steven Gower, MSU Diagnostic Services
July 9, 2008
Several tomato samples have been submitted to the lab over the past 10 days with symptoms consistent with glyphosate injury. In most of these cases, the injury resulted from glyphosate spray drift likely from neighboring corn and soybean fields. Occasionally, the injury resulted from glyphosate contamination in the tank used to apply pesticides to the tomatoes.
Specific symptoms of glyphosate injury will vary depending on several factors including exposure dose, tomato growth stage, growing conditions after exposure, etc. Glyphosate is translocated inside the plant to the newest meristematic regions; therefore the newest growth will be most injured.
Tomatoes injured with glyphosate will have distorted new growth with cupped, fringed and small leaflets. Often, the newest leaves will contain a proliferation of buds and small leaflets. Many of the leaflet bases will contain a yellow to white discoloration – a diagnostic clue of glyphosate injury on tomato.