Dear Doctor Salem, I would suggest contacting the ICRISAT International center who has the mandate for sorghum work in the tropics. They may be able to provide trialing materials and the breeding lines. Another option would be the Texas A and M University program. Generally you need to make a personal contact and explain how you want to use the materials. You might also want to suggest collaborate work which often can open up doors of mutual benefit. Hope you find this information useful. PRH