Application of 2,3,5-triiodobenzoic acid (TIBA) at 1, 2, 4, 5 and 12 g/ha to field-grown snap beans (Phaseolus vulgaris L.) at early bloom caused a reduction in plant height and width but not dry weight. Yield differences occurred with the cultural variables of cultivar ('Sprite' and 'Dark-Seeded Provider') and row spacing (single and double rows) but not with the chemical treatment. Low soil moisture at the time of TIBA application was suspected of interfering with absorption and action of the chemical. In the winter and spring of 1981 greenhouse studies were conducted with 2 g/ha TIBA treatment of double-row snap beans grown under 3 pre-flower moisture regimes. Early yield was increased with the TIBA treatment, but the total yield did not differ due to a reduced second harvest, such that TIBA functioned as a yield catalyst under these study conditions. Environment was a more important determinant of the snap bean productivity as yield increased with more available soil moisture in both trials and decreased with warmer temperatures during the second crop trial. The importance of environmental influences on TIBA effect is discussed. / M.S.