A man believed to be a farmer was rushed to a hospital in serious condition here on Wednesday after he hanged himself from a tree at an AAP rally called to protest the land bill.Aam Aadmi Party volunteers said the man was unconscious and barely breathing when three party activists climbed the tree and brought him down after people saw him hanging.Delhi Chief Minister Arvind Kejriwal was present when the incident took place at the rally attended by thousands at Jantar Mantar in the heart of the capital.