Implementation of hyperspectral radiometry in irrigation management of creeping bentgrass putting greens

Field research conducted in 2003 and 2004 evaluated hyperspectral radiometry as a tool to detect localized dry spots on creeping bent-grass (Agrostis stolonifera L.) puffing greens. Discriminant analysis identified 14 wavebands between 861 and 887 ran that distinguished drought severity. An overall accuracy of 85% was achieved using these wavebands with low-stressed greens correctly classified 91%. High-stressed greens were correctly classified 100% of the time with individual wavebands between 905 and 992 ran using 2003 data as a training model to cross-validate 2004 data. These results suggest these individual wavehands are highly sensitive to early season drought-stress in creeping bentgrass greens and could be considered a more stable portion of the spectrum over time concerning high-stressed creeping bentgrass putting greens. A significant relationship (p = 0.034) was established between average reflectance values of wavebands between 1480 and 1530 nm and volumetric soil water content (VWC). Although not highly correlated, this relationship demonstrated that as VWC increased, reflectance decreased. Data collected in late springtearly summer may be the optimal time to detect areas of putting greens most susceptible to drought stress before unfavorable growth conditions occur.