Cotton leaf curl virus

Cotton leaf curl viruses (CLCuV) are a number of plant pathogenic virus species of the family Geminiviridae. In Asia and Africa the major disease of cotton is caused by the Cotton leaf curl geminivirus (CLCuV). Leaves of infected cotton curl upward and bear leaf-like enations on the underside along with vein thickening. Plants infected early in the season are stunted and yield is reduced drastically. (A. Nadeem and Z. Xiong, University of Arizona) This virus devastated the Pakistan cotton industry in early 1990s where it caused an estimated yield reduction of 30-35%.

from Wikipedia