Economy of Tamil Nadu Main rail junctions in the state include Chennai, Coimbatore, Erode, Madurai, Salem, Tiruchirapalli and Tirunelveli . Chennai has a well-established Suburban Railway network, a Mass Rapid Transport System and is currently developing a Metro system, with its first underground stretch operational since May 2017. Tamil Nadu has a major international airport, Chennai International Airport, that is connected with 19 countries with more than 400 direct flights every day. Other international airports in Tamil Nadu include Coimbatore International Airport, Madurai International Airport and Tiruchirapalli International Airport. Chennai International Airport is currently the third largest airport in India after Mumbai and Delhi
Tamil Nadu state has 17,000 hectares of land under oil palm cultivation, the second highest in India. Dr M.S. Swaminathan, known as the "father of the Indian Green Revolution" was from Tamil Nadu. Tamil Nadu Agricultural University with its seven colleges and thirty two research stations spread over the entire state contributes to evolving new crop varieties and technologies and disseminating through various extension agencies. Among states in India, Tamil Nadu is one of the leaders in livestock, poultry and fisheries production. Tamil Nadu had the second largest number of poultry amongst all the states and accounted for 17.7 per cent of