This has been explained by the fact that most plant stress leads to the breakdown of chlorophyll, which dominates the properties of foliar reflectance throughout the visible domain [5,7�C9].Figure 1.Potential operational http://www.selleckchem.com/products/VX-770.html setup of an active ground optical remote sensing device on irrigation boom (Note: active ground optical remote sensing device not to scale).A wide variety of spectral indices have been successfully used to spectrally detect variations of chlorophyll at the leaf level [10]. However, isolating the spectral chlorophyll signal at the canopy level has proven to be more challenging due to a complex interaction of spectral signals that compose the canopy spectral response [4,11]. Traditionally, AGORS relied solely on the Inhibitors,Modulators,Libraries red (590�C670 nm) and near-infrared Inhibitors,Modulators,Libraries (>760 nm) wavebands to measure the Normalized Difference Vegetation Index (NDVI) [12].

The latter index is reported to be highly sensitive to variations in biomass or Leaf Area Index (LAI), yet insensitive to chlorophyll a+b concentration (Chlab) [13]. Nevertheless, NDVI has been shown to be correlated with Chlab because Chlab often co-varies with biomass [14].Recently, an Inhibitors,Modulators,Libraries AGORS device (ACS-470, Holland Scientific, Inc., Lincoln, NE, USA) has become commercially available that provides additional red-edge (700�C740 nm) reflectance information. Recent research with passive optical sensors suggests that red-edge reflectance information provides important spectral information to remotely predict Chlab [11,13,15]. However, relatively little is known about whether the additional availability of red-edge waveband reflectance information improves Inhibitors,Modulators,Libraries AGORS of seedling stress.

Our objective in this study was to test the hypothesis that the additional availability of red-edge waveband reflectance information would improve AGORS of seedling stress by means of nursery-grown Scots pine (Pinus sylvestris) seedlings.2.?Methods2.1. Study Design and Entinostat LogisticsA total of 945 Scots pine seedlings were sown on 12 February 2008 into 21 Copperblock? 615A containers (Beaver Plastics, Acheson, Alberta, Canada) at the University of Idaho Center for Forest Nursery and Seedling Research in Moscow, Idaho. Copperblock? 615A containers have 45 cavities per container, with a cavity volume of 340 mL and a density of 213 cavities m?2.

Seedlings were grown in a greenhouse for two months and were then selleck bio transferred outside where they received ambient precipitation plus additional irrigation as necessary to maintain 80�C85% water content, expressed as a percentage of total container weight. The growing substrate used was a mixture of equal parts of vermiculite and forestry grade peat moss (Sun Gro Horticulture Distribution Inc., Bellevue, WA, USA). Chlab of tree seedlings was manipulated to simulate stress induced chlorophyll breakdown by applying one of seven different fertilizer rates of controlled-release fertilizer (2.5, 5, 7.5, 10, 12.5, 15, and 17.