The two most common ways to say that something is "salty" in Japanese are karai + and shoppai ▲. I've heard both, but in contrast to what the map indicates, my experience is that shoppai is more often used even in western Japan, with karai meaning "spicy" rather than "salty". I could be wrong, though.
In a number of isolated areas ● shiohaii is said. In the Hokuriku area on the central western coast of Japan ◆ kudui is used.
Shiokarai, shiokaraka, and shuukarasan can be also be heard in a variety of places, throughout Japan▼, including Nagasaki and Kumamoto on the island of Kyūshū, the western edge of Shikoku, central Japan, and Hokuriku.