Palta is one of the most common names to call avocado in Spanish. They call it palta in Chile, Peru, Uruguay, Bolivia and Argentina.

Why do Peruvians say palta?

After digging a little bit in the history of food in the Americas, and speaking with my Peruvian friends, it seems that the avocados came down to this side of the world many centuries ago from Mexico, and the Quechua speaking inhabitants named it palta.

What do they call avocados in Spain?

It became "aguacate," which is the present day Spanish loanword for avocado, so the association with testicle went away with the name change.