As management trends move toward lower mowing heights to achieve greater ball distance and more challenging putting surfaces for the modern golf game, there is a need to understand the impacts of suboptimal mowing especially in concert with fertility programs for ultradwarf bermudagrass. Three eight-week trials were conducted during the 2006 stress period in sub-tropical south Florida on a sand-based putting green known previously to have disease problems. To evaluate the effect of optimal and sub-optimal mowing heights (MH) and nitrogen (N) applications on ‘TifEagle' ultradwarf bermudagrass [Cynodon dactylon Burtt-Davy X Cynodon transvaalensis], turfgrass quality was measured by visual assessment and dry weight accumulation, and by monitoring spectral reflectance. In addition, the experimental spectral reflectance sensor was evaluated to determine if it could detect changes in turfgrass earlier than visual perception. Warmer temperatures and drier weather than the five year average resulted in less disease symptoms (DS) than previous years. Except for one week (Week 6 of Trial 3), correlation of weekly quality scores and reflectance ratios ranged from 0.64 – 0.96 (all P<0.001) throughout each trial. Disease symptoms were not correlated with reflectance ratios for the first week symptoms were present in Trials 2 and 3, but negatively correlated for following weeks. For the two weeks in which there was poor correlation, reflectance ratios determined treatment differences while visual ratings did not. Furthermore, reflectance ratios determined factor interactions clearer than visual quality and DS ratings. Determining visual quality alone did not allow for full interpretation of the interaction of MH and N fertilization. The experimental sensor allowed for a more complete understanding of the onset of DS. Monitoring reflectance ratios can aid turfgrass managers with an early alert to turfgrass stress, and may allow for curative measures to be incorporated into regular turf maintenance to prevent secondary problems.