California avocados are the best in the world. So says downtown restaurant manager Daniel Avalos in a Valley Public Radio story by reporter Ezra David Romero.

The fact that they currently thrive only on a small swath of coastal Southern California is being challenged by UC Cooperative Extension specialist Mary Lu Arpaia. She is on a mission to find avocado varieties that withstand the hot summers and cold winters of the San Joaquin Valley, where irrigation water and crop land are more abundant and cheaper. 

She hopes to find avocado varieties that ripen at various times of...