From Pikipedia, the Pikmin wiki
The Nutrient Silo is a treasure in Pikmin 2, and it is actually a jar of Skippy creamy peanut butter. It is found in the sixth sublevel of Hole of Heroes, which is surrounded with water and aquatic enemies. Use Blue Pikmin to defeat all of the Wollywogs and other enemies, that way retrieving the treasure will be a cinch. It is found in one of the corners in the sublevel.
In the European version, the Nutrient Silo is found on the first sublevel of the White Flower Garden. It will be on one of the edges of the level. The only enemies will be Male and Female Sheargrubs, so take those out first.
“What a fascinating storage container. There's more food crammed in here than I could eat in a lifetime! Louie, however...”
“A food storage tank of bewitchingly titanic size! As legend has it, this item is so captivating that the discoverer tried to claim it for himself.”
Names in other languages