Maybe you envision several varieties of tomato plants, large smaller, grape etc and then wilt or bug disease ruins your vision overnight. Have a back up plan. What would you do if ....... this veggie or that veggie suddenly rots? Delaying the inevitable always prolongs the time in which you will harvest.
Once you notice disease, GET RID OF THE VEGGIE PLANT if a quick spray for control does not work. You will only allow the disease to spread to other healthy plants.
Once I noticed the common southern "wilt" disease, I went into action with two plans - I immediately replaced my tomato plants with "disease resistant" tomato plants AND placed them in large containers. I did the same for our squash because we love it so much. Within a few weeks, we had another harvest on the way.
Procrastination is synonomis with veggie garden disease - move decisively and replace those beginning rotted veggie plants. The cost is minimal and the benedfits are HUGE.
This picture is a perfect example of Squash disease - toss it immediately and replant!!