Decrease in the yield from genetically modified Bt. Cotton and increase in the cost of fertilizers have driven many farmers in the region to distress, Sunny D’Souza, a farmer and member of the Karnataka Rajya Raitha Sangha, has said. He was speaking at a function here on Friday to release a book, ”BT Cotton and Beyond”, which contains deliberations of the Afro-Asian Conclave on ”Status and implications of genetically engineered crops and post-GE technologies for small farmers in Africa and Asia” held in Hyderabad in January.