Spots on Tomato Leaves

Question

I'm an absolute newbie at this. These appeared almost overnight on some older leaves. What are they? Maybe rot? I've been spraying the leaves with water to prevent bugs but I wonder if the remedy isn't worse than the disease...

Answer 1

It looks like you just sprayed the leaves with too much pressure, and it physically damaged them. That happens even more easily with watermelon, but it'll happen with tomatoes, too, if you have enough pressure (the problem intensifies as the range gets closer).

If the pests are aphids, you don't need high pressure to get rid of them with water. You just need to shower them with a shower nozzle, and get the aphids and the plants thoroughly wet. Some pressure is probably good, but you definitely don't need enough pressure to damage the plant. It's a myth that you need to blast aphids off with high pressure. (And you don't even need to use soap.)

Also, the leaves look shiny, like they have a substance on them. I might suspect it as an alternative cause. I'd guess you might have sprayed a mixture of soap and water.

If you don't have any pests yet, I wouldn't worry about spraying with water, especially if you're in a humid climate, but I assume you're probably treating pests.

It doesn't look like a fungal disease. The dark spots are still green, but darker, as if they've been squished.