Q.Snake Plant
I’ve had a border of dwarf snake plants for years. This spring the outer leaves began to wither. Is it a fungus? What can I do? Someone told me that all the snake plants in South Florida were suffering from some kind of disease. Can you help?

Judging by the photo, it looks like you have a leaf spot fungus. For more information on leaf spot fungus and a prescribed course of treatment, please visit the following link:
https://www.gardeningknowhow.com/plant-problems/disease/plant-leaf-spots.htm
Insects can also weaken plants in this manner. As a precaution, I would examine your snake plants for an insect infestation such as thrips, mealy bugs or spider mites. More information on these pests can be found below:
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/mealybugs-control.htm
For more information on the care of snake plants, please visit the following link:
https://www.gardeningknowhow.com/houseplants/snake-plant/snake-plant-care.htm