Pomeg Berry
When you feed your Pokemon a Pomeg berry, its hit points will fall by 10. You can find Pomeg berries being held by some wild Pokemon. In most Pokemon games, excluding "HeartGold" and "SoulSilver," there is a character called the "berry master" who gives out berries as gifts. In "Pokemon Emerald" and "Ruby" versions you can find berries growing next to some of the roads. Pomeg berries can be found on Route 119. After a Pomeg berry has been picked, it takes eight hours for another one to grow in its place.
Kelpsy Berry
Feeding a Pokemon a Kelpsy berry will increase its happiness, but its base attack stat will fall by 10 points. You can get Kelpsy berries from the berry master in each game, although in "Pokemon HeartGold" and "SoulSilver," you can get them from the juggler in Fuschia City in exchange for a Blue Shard item. In "Pokemon Emerald" they can be found growing on Route 115, and they take 12 hours to regenerate after being picked.
Qualot Berry
Qualot berries reduce a Pokemon's defense EV by 10 points when eaten. They are given by the berry master in most games. In "Pokemon FireRed" and "LeafGreen," they are given by a man in Cerulean City, and in "Pokemon Emerald" they can be found growing in a garden next to the berry master's house on Route 123. It takes 12 hours for the berries to regrow after being picked.
Hondew Berry
Feeding a Pokemon a Hondew berry reduces its base special attack EV by 10 points. They are given by the berry master in most games, and can be found by the side of Route 119 in "Pokemon Emerald." In "Heartgold" and "SoulSilver" you can get them from the juggler in Fuchsia City in exchange for a Green Shard item, and in "Diamond," Pearl" and "Platinum" they are found in the fight area.
Grepa Berry
Grepa berries reduce a Pokemon's special defense EV by 10 points. They are given by the berry master in most games, except "Pokemon HeartGold" and "SoulSilver," where you get them from the juggler in Fuchsia City in exchange for a Yellow Shard. They can also be found in the garden next to the berry master's house on Route 123 in "Pokemon Emerald," and take 12 hours to regrow after being picked.
Tamato Berry
A Tamato berry reduces the base speed of a Pokemon by 10 points when eaten. They are given by the berry master in most games, except in "HeartGold" and "SoulSilver," where they can only be won from scratch-off cards in the Battle Frontier area. In "Diamond," "Pearl" and "Platinum" they can be found growing on Route 212, although they take 32 hours to regrow after being picked. In "Pokemon Emerald" you can get them from Kiri in Sootopolis City.