After an assessment of student learning outcomes indicated that information literacy (IL) was a weakness in the plant and soil science programs, instructors in the introductory plant science course collaborated with the Washington State University Libraries to incorporate IL into an existing assignment. The objectives of this paper are to describe the incorporation of an IL web-based learning environment into the course and to evaluate the effectiveness of the environment in improving students' abilities to find and use information in two consecutive classes. The environment featured a series of tutorials covering the IL standards of: needed, accessing, evaluating, and using information, followed by a quiz and an essay for each standard. The essays and a final comprehensive assignment tested the students' abilities to apply the information learned from tutorials. The class average on the pretest, taken before the online tutorials, was 59% in 2007 and 51% in 2008. The average quiz score after completing the tutorials was 89% and 80% in 2007 and 2008, respectively. Student performance on the quizzes was correlated with subsequent performance on the assignment both years, suggesting that the online learning environment shows potential as an effective tool in helping students learn and apply IL concepts.