Knowledgebase
Tomato Leaf Curl #339353
Asked July 04, 2016, 6:27 PM EDT
I have been trying to figure out what is causing my tomato plants leaves to curl. I have 6 plants and only two are doing OK. From looking at Youtube videos it looks more like herbicide damage than anything else, but the lower leaves are drying out and dying as well.
I amended my soil with an organic Ecogrow compost. After a few weeks the leaves were looking a little yellow so I added a tomato/nitrogen fertilizer from Happy Frog. Could I have over dosed them? Could it be herbicide spray drift from a neighbor? I live in town in Boulder.
I have attached some photos. All images are from the same plant.
Thanks in advance. Ken Bernstein
Boulder County Colorado
Expert Response
Thank you for attaching the images which verify that your diagnosis is accurate. Your tomatoes have been affected by herbicide which may have been from one or more of several sources:
1. You used a sprayer which previously held herbicide.
2. Herbicide was applied nearby and, then, the tomatoes were affected either by off-target spray drift or, if the temperatures exceeded 80F, volatilized herbicide.
3. Herbicide carryover due to the presence of long-lasting herbicides present in composted organic matter such as composted manure, either commercially packaged or from a local farmer.
Herbicide carryover has been troubling home gardeners for approximately 10 years. Of all the plants in vegetable gardens, tomatoes are the most susceptible to damage.
Numerous images of such damage are here: http://whatcom.wsu.edu/ag/aminopyralid/.
If you suspect herbicide carryover may be the source of the distorted growth, please review this link, beginning on page 2: http://www.ext.colostate.edu/sam/nl/11-summer.pdf. And, then, to verify the source of the contamination, do the simple bioassay described in the link at the end of the article.
