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