over fertilized? Leaves yellow brown wilted & brittle

[Scgardener]

Please look at these pics I'm pretty sure I've over fertilized maybe and need to know if I can save these plants or what my next step should be , The squash and zucchini have pretty dark green growth but then start to look like this , I've now noticed it on the tomato plant and cucumber plants , the okra and bell pepper plants are very small and seem to be not growing, the leaves are yellow dry brittle , the tomoto leaves are brown in the edges and appear wilty looking , I did place sevin dust on them so that's the white residue cause I thought at first I might had a pest issue

any help or advice would be greatly appreciated!

[Gary350]

What fertilizer did you use and how much? Are you using lime on your plants for Blossom End Rot? Be sure to use pellet lime not white lime. What is that I see in your soil do you have wood chips or tree bark in the soil that can suck all the nitrogen from the soil.

[rainbowgardener]

It's powdery mildew, a fungal disease that squash family things are quite prone to, especially in high humidity conditions.

Help prevent it by mulching well (to help prevent soil from splashing up on the leaves) and only watering the soil, not the leaves.

To treat it, take off all the affected leaves and trash them. Then spray everything that's left with an organic fungicide: diluted milk, hydrogen peroxide, or baking soda solution. Repeat the spraying weekly until new leaves are coming in clean and then every two weeks after that. Fungicides (all of them, even the chemical poisons) work much better preventatively than trying to treat established disease.

[Scgardener]

The soil is a mixture of organic compost and a top soil that was bought from a landscape supply , i
Just used a organic fertilizer bought from lowes that was extended release ,

Thank you for the advice on the fungus/bacterial remedy , I have been cuttin the damaged leaves and I will give this spray a try for sure ! Thank you so much

[Lindsaylew82]

Ya, looks like late powdery mildew to me as well.

I like neem oil as a fungicide as well! Plus is messes with the squash bug reproductive cycle. Total bonus!!! That leaf looks big for SC....Ah! Columbia! Armpit of the state! Hot and sweaty! And just right for fungi!!!

My okra and peppes are just kinda hanging out, too. Looking for that scorching heat that they love! Once it warms up, they'll get their gears going!

[Scgardener]

Yea it's been hot and humid so the powder mildew sounds about right , thanks everyone for your help , I hope I can not lose anything ! Have a great weekend !