His contributions to the seed industry were recognized with the Seed Science Award from Crop Science Society of America, 1995. Maguire's research included seed vigor, aging and deterioration, including seedborne diseases. In 1962 he helped develop a speed of germination test still used to determine seedling establishment. He has also developed a cold test to evaluate the vigor of cereal seeds and a solid-matrix priming technique to invigorate seed and a technique for eradicating TCK smut in wheat. The TCK smut eradication technique could become important in exports to China.
Marketing requires phytosanitary certificates attesting that seed is free from blackleg.
Recently he has taken up sailing and woodworking. Jim and his wife, Jan, will remain residents of Pullman. WSU is establishing a seed technology scholarship in his name.