Berries, they help your Pokémon in battle and help raises their contest status.
Here you will find a list of all the berries and what they do:

Picture Number Name Effect
#01 Cheri Berry Heals Paralysis
#02 Chesto Berry Heals Sleeping
#03 Pecha Berry Heals Poison
#04 Rawst Berry Heals Burn
#05 Aspear Berry Heals Frozen Status
#06 Leppa Berry Recovers 10PP to an attack
#07 Oran Berry Recovers 10HP
#08 Persim Berry Heals Confusion
#09 Lum Berry Heals Any Status Condition
#10 Sitrus Berry Recovers 30HP
#11 Figy Berry Recovers 1/8 HP and confuses any Pokémon that doesnt like Spicy Flavour
#12 Wiki Berry Recovers 1/8 HP and confuses any Pokémon that doesnt like Dry Flavour
#13 Mago Berry Recovers 1/8 HP and confuses any Pokémon that doesnt like Sweet Flavour
#14 Aguav Berry Recovers 1/8 HP and confuses any Pokémon that doesnt like Bitter Flavour
#15 Iapapa Berry Recovers 1/8 HP and confuses any Pokémon that doesnt like Sour Flavour
#16 Razz Berry Plant in the Earth to grow Berries for Pokéblocks
#17 Bluk Berry Plant in the Earth to grow Berries for Pokéblocks
#18 Nanab Berry Plant in the Earth to grow Berries for Pokéblocks
#19 Wepear Berry Plant in the Earth to grow Berries for Pokéblocks
#20 Pinap Berry Plant in the Earth to grow Berries for Pokéblocks
#21 Pomeg Berry Lowers Effort Points for HP by 10 Points
#22 Kelpsy Berry Lowers Effort Points for Attack by 10 Points
#23 Qualot Berry Lowers Effort Points for Defense by 10 Points
#24 Hondew Berry Lowers Effort Points for Special Attack by 10 Points
#25 Grepa Berry Lowers Effort Points for Special Defense by 10 Points
#26 Tamato Berry Lowers Effort Points for Speed by 10 Points
#27 Cornn Berry Plant in the Earth to grow Berries for Pokéblocks
#28 Magost Berry Plant in the Earth to grow Berries for Pokéblocks
#29 Rabuta Berry Plant in the Earth to grow Berries for Pokéblocks
#30 Nomel Berry Plant in the Earth to grow Berries for Pokéblocks
#31 Spelon Berry Plant in the Earth to grow Berries for Pokéblocks
#32 Pamtre Berry Plant in the Earth to grow Berries for Pokéblocks
#33 Watmel Berry Plant in the Earth to grow Berries for Pokéblocks
#34 Durin Berry Plant in the Earth to grow Berries for Pokéblocks
#35 Belue Berry Plant in the Earth to grow Berries for Pokéblocks
#36 Liechi Berry Raises Attack when HP is below 1/3
#37 Ganlon Berry Raises Defense when HP is below 1/3
#38 Salac Berry Raises Speed when HP is below 1/3
#39 Petaya Berry Raises Special Attack when HP is below 1/3
#40 Apicot Berry Raises Special Defense when HP is below 1/3
#41 Lansat Berry Raises Critical Hit Ratio when HP is below 1/3
#42 Starf Berry Raises Any Stat when HP is below 1/3
#43 Enigma Berry Morphs into E-Reader Berries