My 3 years old nectarine plant grown from seed have these spots. Around 70% of leaves have them. Any organic way to treat if possible? Otherwise I may need to buy pesticide from shops?
Are there any infestation under the leaves? any distortion of leaves will mean peach leaf curl which can affect nectarines. Have you watered the leaves in bright sunlight?
Basically, in my experience, we mostly have to combat 2 issues in the garden, (specially with fruit producing plants and trees) - Insects, and some type of fungus... So these problems usually open to door for other headaches. Like a rot of any type anywhere will invite pests, while insects which leave an open wound on the plants, will naturally invite plant viruses and fungus. So that's how problems start complimenting each other unfortunately... However worry not, as there is a single fix which solves all problems - Neem! Yes, any type of extract from Neem tree works great as both an organic pesticide, as well as a fungicide. So that's what I'd advise here. As chemically it's a natural fungicide, however as a pesticide it's also totally safe - Because it doesn't kill the insects with toxicity. Rather it simply alters their metabolism. So insects just forget to eat, (they think they have already eaten), thus they starve to death. Or they forget to reproduce at the correct time... Best part is that Neem extracts are not toxic to humans or animals. Also doesn't harm any of the beneficial insects in the garden either. So it's literally a win win situation all around for everyone everywhere! Only downside is the cost. As elsewhere in the world Neem extracts are costly. Except for my part of the world, where Neem grows naturally. I myself have 3 adult trees of Neem growing on my property.
We talked a bit about the Neem tree and it's benefits in 2011 over here, (link below). https://www.gardenstew.com/threads/neem-tree-uns-tree-of-the-21st-century.23195/
It looks like a fungus. I use whole milk mixed with water 2 parts milk to one part water to spray on the leaves. It takes a time or two to repeat spray and really works. The fat in the milk suppresses and smothers the fungus spores. Being sure to clean up any leaves and cover the soil to smother spores in the soil.
