Tomato problem - fungus?
I have some type of problem affecting my tomato plants and am wondering whether soil testing would help identify the cause. This problem affects some but not all of the plants and has been happening for 3-5 years. Pictures: https://goo.gl/photos/ZxvhMHq7A68TMWhV6. It doesn't seem to be spreading beyond a small area. I have been around the country but haven't seen this before.
Thank you for sharing photos. May I get additional information, please? How many years have tomatoes been grown in this small area? If other crops have been grown here, how did they grow? How is this area watered, and how often? Has fertilizer been used?
I see onions growing very close to one of the plants - is this being done to repel pests?
I do recommend doing a soil test to learn more about the soil in this area. You may purchase a soil test kit at http://msue.anr.msu.edu/resources/soil_test_kit_self-mailer or you may be able to purchase one at your nearest MSU Extension office, http://msue.anr.msu.edu/county/info/wayne