Can someone tell me what this disease might be? I don't think this is rust or black spot. Thanks.
I have no idea what that is on your rose. I see you posted it on the main forum also. You will get better results and answers on the main forum.
Here we mainly post our rose pictures.
I'm just a newbie dummy (LOL)
Wish I could of helped more, maybe someone else has the answer to your problem.
I searched some websites for you, but, could NOT come up with anything that looks like what you have on your leaves.
It resembles Blackspot somewhat, but, the pattern is a weird one. Hummmm. I'm kind of interested in what you have also for future reference. Hope you get your answer!
You have 2 responses to your question on the main forum.
Thank you all for your responses, especially to Jim for helping out. I also sent a picture to our local Agricultural extension office. They forwarded it to the plant pathology department at Kansas State University and this was the response from the plant pathologist "My first thought is physiological since all of the spots are clustered along the margins. Diseases tend to be more scattered. Another vague thought would be a Cercospora leaf spot. I tend to see it on roses in wet years. It is pretty minor. It has a light colored center with a reddish purple border. The symptoms here look similar but I still don't think the pattern fits because it is usually more scattered. At this late in the season I wouldn't recommend any control measures and next year it likely won't be a problem if it is drier and warmer". The county extension agent said "Most likely non disease. I think it looks like a scorch symptom from a spray. Often the oil carriers in pest control products can cause a burn like this if used above label rate or when temperatures are too high".
Once again thanks to all. This is a great forum!