My sweet potatoes are growing quite well but.
It seems like a deer enjoys them as much as me. This has happened a number of times in the past. They also like beets and carrots. I make a repellent that not only works but it is cheap. I store it in pint containers in the freezer and use when it is needed.
Here is the repellent I use:
Blend two eggs and a cup or two of cold water at high speed. Add this mixture to a gallon of water and let it stand for 24 hours. Then spray the mixture on foliage. The egg mixture does not wash off the foliage easily, but re-application two or three times a season may be needed.
This mix is also said to repel rabbits.
One caution is to avoid spraying it too close to harvest, as the raw egg on the vegetables can cause salmonella problems.