With hopes of developing apple trees that need fewer chemical pesticides to control insect attacks, a UC Davis plant scientist and colleagues from a biotechnology company recently planted genetically engineered apple seedlings in a commercial nursery in California's Central Valley. The planting near the town of Oakdale represents the first known field trial of "transgenic" apple trees -- seedlings that carry genes not normally found in the apple tree. Since 1987, more than 300 field trials of transgenic plants have been completed or are in progress nationwide, according to the U.S. Department of Agriculture. "We want to see what types of variabilities occur among these apple trees when they are planted in nursery rows as commercial trees would be," said Abhaya Dandekar, an associate professor of pomology at UC Davis. "This will give us the opportunity to evaluate the vigor, size and performance of the trees in the field." Dandekar, who is working with Plant Research Laboratory of Modesto, has been doing laboratory studies on gene transfer in apple trees for the past three years. The young apple trees carry a gene for insect resistance and several marker genes, which simply serve as indicators that a foreign gene has been transferred and incorporated into the apple trees.