Our primary goal in this research is to study the spatial distribution of fiber maturity and length within a cotton plant. It is of the utmost importance for geneticists and biotechnologists to realize that the fibers sampled for analysis and testing should be representative of the plant or genotype under study. Two genotypes were selected, namely TM-1 and im.  TM-1 is a wild type cotton and the genotype im is an isogenic mutant of TM-1, which has been reported to be genetically immature.  Twenty plants each, of TM-1 and im were tagged in the field and harvested.  Cotton bolls were identified by fructifer branch number and by position within each branch.  Cotton samples collected from different positions in the plant were hand-ginned to prevent fiber breakage.  Advanced Fiber Information System and High Volume Instrument were used to measure length, maturity ratio and their distribution as well as other pertinent fiber properties. The results obtained show that there is a large variability for both, length and maturity distributions when progressing from the bottom of the plant to the top. In addition, the extent of the fiber quality variation appears to be genotype specific.  These results demonstrate that appropriate sampling protocols need to be developed for single plant testing (cotton breeding for example).