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!