The environment during the growing season is a major determinant of fiber quality and, therefore, of price in upland cotton [Gossypium hirsutum]. Water deficits during fruit [boll] formation and seed and fiber maturation increase the number of underdeveloped seeds [motes], decrease fiber maturity, and increase fiber thickness [and micronaire]. Low insolation during fruit development also decreases fiber maturity. All of these changes associated with environmental conditions lower bulk fiber quality by increasing the number of point sources of low quality fiber. Plant mapping techniques have been used to determine the effects growth environment and two types of row-irrigation on mote frequency, fiber/seed maturity, and fiber quality [Immature Fiber Content, Fine Fiber Content, Short Fiber Content, Length, Diameter, Area, and micronAFIS as determined by AFIS, Advanced Fiber Information System] with respect to boll and locule position. Elevated Short Fiber Content, observed in fiber from the rainfed [control] plants and attributed to early-season drought, was not found in fiber grown under in-row micro-irrigation. Increased Fine Fiber and Immature Fiber Fractions associated with low insolation were observed in fiber produced under rainfed and irrigated conditions. Plant-mapping population statistics, coupled with AFIS measurements, have great potential as predictors of the abnormal seed and fiber development and the probability of undyed fabric "white specks" associated with the presence of motes and immature fiber.