Hi folks,
Could you please help me in identifying what this could be on the leaves of one of my seedlings. It appears to be both on the front of the leaf and the back. I haven’t sprayed anything on them. It is in the sun for most of the day. It seems to spreading pretty quickly too. Thanks so much everyone, I appreciate any help you could offer.
I cannot figure out how to post more than one pic in a post so I posted them in three different ones.
I took some leaves off so I could photograph them on the back side.
Again thanks so much everyone.
Sunburn?
Downy mildew. Isolate those plants from the rest. When the weather gets hot, it will go away.
downy mildew spreads very, very fast and will kill the plant in a short time. If these seedlings are already affected and you want to save them, then you need to certainly seperate them from the rest and spray them as soon as possible. Here is a link how to treat.
Patrick
I’m hesitant to diagnose Downy Mildew. That might also be Cercospora, which is far less destructive. Isolate the plant(s) affected and if there is FAST and dramatic leaf drop, then you can be sure its Downy.
I think likely Cercospora as well. Those tiny holes were probably where the organism entered the leaf via mechanical damage.
The leaves probably got punctured by prickles being jostled about by something like wind blown rain.
Cercospora is relatively harmless, not to say Downy might not be present as well.
Nice leaves btw!
Thanks so much to all of you for your responses.
I also posted this on another rose forum and someone there told me it could be spot anthracnose disease. When I look this up on the web it states that this is very common in white dogwood trees, well my rose seedling is in a pot sitting fairly close to a dogwood tree as many of my other seedlings are but they don’t have this. This rose is the only one that has these spots…so far that is! I have been picking the white flowers that are falling from the tree out of the seedling pots all week so this might be the cause, I just don’t know.
This seedling is a little over a year old so it is pretty well established and healthy. I’m hoping it will overcome this because it is a great looking rose. I will definitely isolate it, wait and keep my eye on it for leaf drop and will keep you posted. Thanks again for all of your help and Patrick thank you so much for the link, it was very helpful and I will keep it in my favorites for future reference.
Yes, could be anthracnose as well. Cercospora and Anthracnose affect several different genus. Both as leaf spot organisms.
Species are usually host specific but anything is possible.
I almost forgot…where can I get Aliette, just in case it is Downy? Thanks
Where to find Aliette? Depends on where you are. Ask at your local feed and farm store, if you have one. In some parts of the country, Agri-Fos is available and apparently works. In some states, you may not be able to find either of these.
Jeanie,
It looks much more like cercospora–Downy usually has a lot more purply/redpinkness associated with it. Daconil used to be the treatment, but up to date treatments are on the web.
Jackie
Thanks so much Jackie, going to Lowes tomorrow so I will look for Daconil, I think I remember seeing it there before.
Thanks again everyone for your help.