Drying from the bottom up can be due to something other than verticillium or fusarium. That strawberry & asparagus are doing well is further evidence for that.

Although those two fungi are certainly possible, I'd suspect watering issues in a home garden.

How do you water, how often and for how long?
How do you determine when to water again?

Soil should be evenly moist to at least 12 to 15 inches deep.

Eggplant full of seeds may be harvested too late.

I hope you are right about it not being the soil born diseases. We use a drip water system that runs every evening for 30 min. What is the best way to determine depth of moisture?

Take a trowel, stick it into the soil and look to see how far down it went. 10 to 12 inches is minimum. (now cover your ears because folks will scream about that not being enough.)

I doubt 30 minutes is long enough.

I passed by the local garden shop with a sample. He thinks it's a spider mite infestation by the look of the leaves. He sold me a Bayer insecticide product, said I could use it now on the plants without worry, just remove the maturing fruits first. I am surprised insects like those can do such damage. Like with most things, I should have noticed earlier and acted before it got this bad.

Do you see the mites? Stippling is present on the leaves long before the leaves dry.
Pictures could help us help you.

INSECTS WILL ATTACK SICK PLANTS....BUT HEALTHY PLANTS HAVE GOOD DEFENSES....IT TAKES HEALTHY SOIL TO RAISE HEALTHY PLANTS....WEEDS DON'T EVEN LIKE RICH SOIL...WE AS GARDNERS NEED TO STUDY MORE ON HOW TO BUILD RICH HEALTHY SOIL BEFORE WE PLANT...NO POISONS, NO CHEMICAL FERTILIZER, NO TILLING, ETC...ROCK DUST, BIOCHAR, HUMATE (IN DRY AREA, BURING SOME OLD ROTTING LOG PCS TO HOLD WATER IN DRY WEATHER) HOPE THIS GIVES YOU SOME GOOD IDEAS...ROY