Economic yield responses from starter fertilizer applications have been reported for cotton (Gossypium hirsutum L.) grown at a number of locations and under various management practices. The purpose of this study was to investigate the effect of ammonium polyphosphate, applied as starter fertilizer, on cotton root growth and lint yield under both conventional tillage and no-till production. Treatments consisted of a check, 1.5 gal. 11-37-0/A applied in-furrow, 7.5 gal. 11-37-0/A applied in a band two inches below and to the side of the seed, and 7.5 gal. 11-37-0/A applied as a surface band over the row. Root samples were collected at early bloom. In 1993, significant differences in root length density, RLD, were not detected among the starter treatments under conventional tillage. Under no-till, however, RLD was significantly (p<0.05) higher for the 1.5 gal./A in-furrow treatment. Mean RLD for this treatment was 0.64cm/cm³ in the 0 to 10 cm layer compared with 0.35cm/cm³ for the check plot in this same soil layer. At 33 days after planting, shoot weight was significantly higher for the 2X2 band treatment under conventional tillage. No other significant differences in early growth were detected among any of treatments. Cotton lint yields were not significantly increased by the starter treatments under either tillage system.