I want to add values in picklist, other then default values which are given at the time of creation of custom object field with data type Picklist. Suppose I created a custom object named: customObject__c then i created a new custom field with data type picklist and provided values while creation. Now I want to add more values in that but from the Apex code. Is there any way to add more values in picklist, without using MetaData API?
No, you'll need to use the metadata api.