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Georgene L. Johnson, Thomas R. Sinclair and Kevin Kenworthy

monitored by measuring the normalized difference vegetation index (NDVI) using a Field Scout® TCM 500 “NDVI” turf color meter (Spectrum Technologies, Inc., Plainfield, IL) daily for each drying pot. The instrument was placed directly on the turfgrass because

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Reginald S. Fletcher, David E. Escobar and Mani Skaria

The normalized difference vegetation index (NDVI) provides relative estimates of vegetation vigor, density, and health. Little information is available on the application of NDVI imagery for citriculture. The objective of this study was to evaluate airborne NDVI imagery for assessing tree conditions in citrus (Citrus spp.) orchards. Images of two south Texas citrus groves with stressed and nonstressed trees were qualitatively evaluated. Stressed trees were easily detected from nonstressed trees in the images. The images were also helpful for developing survey plans of the citrus groves. Our results indicated that airborne NDVI images could be used as a tool to assess tree conditions in citrus orchards. Findings should be of interest to citrus growers, extension agents, agricultural consultants, and private surveying companies.

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Monica Ann Pilat, Amy McFarland, Amy Snelgrove, Kevin Collins, Tina Marie Waliczek and Jayne Zajicek

order from highest to lowest average NDVI value. Table 1. Minimum, maximum, and average normalized difference vegetation index (NDVI) for metropolitan statistical areas (MSA), ranked in order highest to lowest average NDVI in the study of the effect of

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Mingying Xiang, Justin Q. Moss, Dennis L. Martin and Yanqi Wu

), turf quality (TQ), normalized difference vegetation index (NDVI), dark green color index (DGCI), and visual rating (VR) for 10 common bermudagrass and ‘SeaStar’ seashore paspalum under nonsalinity control and salinity treatment of 15 dS·m −1 . Before

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Libertad Mascarini, Gabriel A. Lorenzo and Fernando Vilella

In roses (Rosa ×hybrida L.), the bending of branches is a technique that modifies the canopy of the plant and could affect such parameters as the leaf area index (LAI), the quality of reflected light, and the water index (WI) of the plant. The measurement of spectral reflectance with remote sensors is a nondestructive, quick, and simple method to study these parameters. The aim of this paper is to quantify the modification of reflected radiation quality, the LAI and the water index of the plant with different canopies, and its impact on flowering and the number and quality of flowers produced. In R. ×hybrida `Terracotta', using the spectral crop reflectance, the red: far red ratio [red (R) = 680 nm; far red (FR) = 730 nm], percentage of blue light of reflected radiation, and vegetation indices [normalized difference vegetation index (NDVI), simple ratio index (SRI), water index (WI)] were calculated in two architectural managements: traditional (upright hedge) and bent shoot. NDVI had a greater correlation with LAI than SRI (r2 = 0.98 and 0.85, respectively), but SRI was more reliable for LAI values of 1 to 3.5. The bent shoot system compared to the traditional one decreased the R:FR ratio of reflected radiation and increased LAI and plant water content. These changes were related to a higher commercial quality of the flowers (longer flowering shoots with a larger stem diameter and fresh weight), although there was no significant difference in the number of flowers harvested. The period that showed the largest difference in the quality of the flower using the bent shoot system had a LAI of 2.8 vs. 1.8 with traditional management and a marked reduction in the R:FR of the light reflected by bent plants. The bent shoot system advanced the peak production by 1 month at the end of winter and improved the flowers at a time when sun radiation is limiting factor for production.

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Thomas J. Trout, Lee F. Johnson and Jim Gartung

photosynthetically active radiation absorbed by plant canopies ( Asrar et al., 1984 ; Daughtry et al., 1992 ; Goward and Huemmrich, 1992 ; Johnson and Scholasch, 2005 ). Spectral indices such as the normalized difference vegetation index (NDVI), derived as the

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Dana Sullivan, Jing Zhang, Alexander R. Kowalewski, Jason B. Peake, William F. Anderson, F. Clint Waltz Jr. and Brian M. Schwartz

evaluated: ratio vegetation index (RVI) and normalized difference vegetation index (NDVI) as follows: Surface firmness was measured in Dec. 2009 and Jan. 2011 using a 2.25-kg CIST and the TruFirm turf firmness meter. For the CIST, the ratio of maximum

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Jeffrey C. Dunne, W. Casey Reynolds, Grady L. Miller, Consuelo Arellano, Rick L. Brandenburg, A. Schoeman, Fred H. Yelverton and Susana R. Milla-Lewis

for testing null hypothesis of no effects from the analysis of variance for normalized difference vegetation index (NDVI), turfgrass cover and turfgrass uuality from data collected on 29 Sept. 2011 and 11 Sept. 2012 at the Lake Wheeler Turfgrass Field

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Alexander R. Kowalewski, Brian M. Schwartz, Austin L. Grimshaw, Dana G. Sullivan and Jason B. Peake

NDVI revealed significant differences among the main effects of location and hybrid before the initiation of traffic, and no location × hybrid interaction was observed ( Table 2 ). Normalized difference vegetation index values at the Coastal Plain

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Mingying Xiang, Justin Q. Moss, Dennis L. Martin, Kemin Su, Bruce L. Dunn and Yanqi Wu

least significant difference ( lsd ) after arcsin (DIA/100) transformation. GreenSeeker TM Normalized Difference Vegetation Index Normalized difference vegetation index is a parameter correlated with leaf area index and with visual appearance of