Palm oil accounts for about 65% of all vegetable oil trade internationally and demand for this resource continues to rise. Efforts are underway to try to curb the resulting rainforest destruction. One effort, begun in 1974, involved cloning the palm oil plant. Researchers took cells from leaves of the most productive trees and grew them in a lab dish to produce cloned seedlings. They expected to increase yields per hectare by 30%. But today less than 1% of the area devoted to oil palms uses clones because some of the cloned trees produced fruit that develo abnormally, appearing jagged and forming athick outer coating.