Here is the Texas Grano 502 Onion, Allium cepa var. cepa. The Texas Grano 502 Onion has been grown in texas since the mid 1940's. Here is the Texas Grano 502 Onion, Allium cepa var. cepa. The Texas Grano 502 Onion has been grown in texas since the mid 1940's. This type is often called Short-day onion and is considered a sweet onion. It has a rich, strong oniony flavor that goes with many dishes! They are Insect an disease resistant to pink root disease. 180 days This type is often called Short-day onion and is considered a sweet onion.