Six cotton, Gossypium hirsutum L., genotypes, which had been selected for greater lateral root growth in trifluralin treated soil, from three different crosses were evaluated in laboratory and field tests. After 24 hours in wetted germination paper, acid-delinted seed with uniform radicle extension from each genotype and parent were selected and planted in plastic containers containing trifluralin treated soil. After 7 days at ca. 28C, soil was washed from the intact seedlings. Lateral roots were counted and root hypocotyl and cotyledons were sectioned from each seedling. Seedlings from the selected genotype tended to have more lateral roots, shorter hypocotyls and higher seedling weight per hypocotyl length than seedlings from their respective unselected parents. No adverse effect of the selection pressure was observe for agronomic performance in three field tests.