Within last week the leaves on my apples, quince and roses have been turning brown around the edges. This coinsided with me spraying some diluted dish soap on them to stop an aphid infestation, and I may have made the solution too concentrated. On the roses, the little brown dots look like a chemical burn to me. However, the leaves also started turning brown around the edges a couple of days later.
On apples and the quince, there are no dots, just browning around the edges. On the quince it is most severe, and happened practically overnight. It is mostly seen on mature leaves and not the new tips, which is an argument against soap damage.
The trees are all newly planted this spring, and have been doing fine until now. They get watered intermittently, if there is no rain for more than three days I’d say. I’ve been fertilizing them with organic 4-4-4 every couple of weeks, with an occasional booster of blood meal to promote growth. The only apple that is unaffected so far is Crimson Crisp. Sweet cherry and grapes look fine too.
Based on my research, the differential diagnosis includes:
Soap damage/chemical burn
Aphid damage
Nutrient deficiency (potassium?)
Microelement deficiency
Drought/water shortage
Fireblight
Other infections
Trying to figure out what I can do to minimize/reverse the damage. Thank you in advance!
Rose with likely chemical burn on the right and tip browning on the left:
Rose with likely aphid damage at the tip:
Quince:
Arkansas black:
Virginia hewes crab:
Enterprise:
Fuji:
Ashmead’s Kernel:
