Hijjah 24, 1431, Nov 30, SPA -- Indian President Pratibha Patil Monday concluded her four-day visit to Syria, which is expected to leapfrog the bilateral commercial and economic ties and double the trade turnover in the next two years. After visiting the International Centre for Agriculture Research in the Dry Areas (ICARDA) in this ancient city, Pratibha Patil, the first Indian head of state to visit this West Asian country, left for New Delhi. She had arrived here on the second leg of her nine-day tour of the Gulf and West Asia region after a five-day visit to the United Arab Emirates, the largest trading partner of India, the Press Trust of India reported.