The initial surge of interest in precision agriculture technologies exhibited by innovators and early adopters involved in crop production appears to have crossed over an important threshold. As valuable field experience increases and learning by doing advances, successful applications of management practices are being identified even though few are adequately documented with economic benefits. Access to accurate information pertaining to applications of site-specific management would be expected to motivate more producers to incorporate technology uses with crop production. This next group of producers has been watching technology developments as they preferred to avoid risk and wait for identifiable benefits. Waiting for detailed case studies involving high value fruits and vegetables may be the wrong approach to take. Fierce competition and strict confidentiality are expected in the fresh market industry. Thus, personal experience with technology becomes more relevant to innovative producers than published literature. This is especially true in California where 350 different crops are produced. High resolution imagery from digital aerial and satellite sensors has been used in crop production in California to identify plant stress, direct plant tissue and soil sampling efforts, and provide information for analysis and interpretation of crop growth. Examples of remote sensing imagery that have provided valuable in-season progress reports will be identified. The focus will be on practice, not theory, as seen from an industry perspective.
Thomas J. Trout, Lee F. Johnson and Jim Gartung
appropriate only for very large fields or for regional assessments. High spatial resolution satellite imagery is available commercially, although costs can be relatively high and users must compete for instrument time. In terms of operational use
Francisca López-Granados, M. Teresa Gómez-Casero, José M. Peña-Barragán, Montserrat Jurado-Expósito and Luis García-Torres
of using high spatial resolution and multispectral satellite imagery for mapping irrigated crops for the improvement of irrigation management. Materials and Methods Study site. The study was conducted within the irrigation community on
Edward L. McWilliams
Hurricanes strike the Gulf Coast of the United States every few years. We briefly describe generalized hurricane tracks for the Gulf Coast and vegetation damage using NDVI satellite imagery as well as slides of damaged urban trees in Florida. The impact of recent hurricanes on both pecan defoliation and production and on initial damage and subsequent recovery of various ornamental trees is described. Pecan harvests were greatly reduced by hurricanes that struck late in the season in both Alabama and Texas. Varieties of pecans varied in their susceptibility to various stresses. Pine forests were sometimes devastated by certain hurricanes while live oaks, various shrubs, and important insects often survived the same storms with little damage. Many exotic ornamental plants including Chinese tallow are either adventive or invasive along the Gulf Coast. Species escape from cultivation over a long period of time and exhibit different invasion lag phases. In Texas and Louisiana, hurricane damage to native trees allowed Chinese tallow seedlings and saplings to subsequently dominate some areas as a result of the disturbance. One delayed ecological response to hurricanes and typhoons is an acceleration of ongoing exotic plant invasions.
Derald A. Harp and Edward L. McWilliams
Urban areas are typically 2 to 3°C warmer than surrounding rural areas throughout the year. Winter minimum temperatures are often 4 to 5 °C warmer in the city and, during extreme episodes may exhibit differences of 12 to 13°C. Because the USDA Hardiness Maps compile readings from individual stations in an area, temperature differences may not be apparent at the local scale. This study was conducted to compare ornamental plant damage during Winter 1995–96 in Fort Worth, Texas. AVHRR 1-km thermal satellite imagery was used to determine the warmest and coolest portions in Fort Worth, Texas. Each temperature area was divided into five 0.5-km blocks on the basis of similar landscape features and plant types. During Mar. 1996, these areas were evaluated on the basis of plant damage to several species. Asian jasmine (Trachelospermum asiaticum), indian hawthorn (Raphiolepis indica), St. augustine turf (Stenotaphrum secundatum), southern magnolia (Magnolia grandiflora), and Live Oak (Quercus virginiana) were the primary species damaged. Asian jasmine and St. Augustine turf were either completely killed or severely damaged in the coldest areas but suffered only moderate or light damage in the warmest areas. Indian hawthorn, live oak, and southern magnolia suffered leaf and stem damage in the coldest areas but little to no damage in the warmer areas.
Monica Ann Pilat, Amy McFarland, Amy Snelgrove, Kevin Collins, Tina Marie Waliczek and Jayne Zajicek
living within the county; therefore, data were not available from the reporting agency (A. Vincent, personal communication). Mapping vegetative cover. Landsat 5 TM [U.S. Geological Survey (USGS), Sioux Falls, SD] satellite imagery was obtained from USGS
Lee F. Johnson, Michael Cahn, Frank Martin, Forrest Melton, Sharon Benzen, Barry Farrara and Kirk Post
( Melton et al., 2012 ). SIMS combines public Earth-observation satellite imagery with FAO-56-based calculations ( Allen et al., 1998 ; Allen and Pereira, 2009 ) and CIMIS ETo ( Johnson et al., 2010 , 2011 ; Melton et al., 2012 ). Satellite data are used
Ghazal Tarar, Coleman L. Etheredge, Amy McFarland, Amy Snelgrove, Tina M. Waliczek and Jayne M. Zajicek
, Redlands, CA). To determine the percent urban canopy or vegetation levels for the MSAs in this study, a normalized difference vegetation index (NDVI) was calculated from satellite imagery (Landsat) for each MSA. Landsat 5 imagery was obtained from U
Elvis A. Takow, Edward W. Hellman, Andrew G. Birt, Maria D. Tchakerian and Robert N. Coulson
, soils, elevation, and hillshade. Figure 5 shows AVATXIS displaying a map of the Texas Hill Country AVA; note that satellite imagery is the base layer, whereas wine region and average annual precipitation have been selected as dynamic layers from the
Thomas G. Bottoms, Timothy K. Hartz, Michael D. Cahn and Barry F. Farrara
. Agr. 58 48 53 Hart, Q.J. Brugnach, M. Temesgen, B. Rueda, C. Ustin, S.L. Frame, K. 2009 Daily reference evapotranspiration for California using satellite imagery and weather station measurement interpolation Civ. Eng. Environ. Syst. 26 19 33 Hochmuth