20 research outputs found

    Effect of Irrigation Application Devices on Boll Set, Cotton Yield and Fiber Quality

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    Previous research concluded that water sprayed above the canopy on open flowers interrupted pollination causing flower drop and subsequent reduction in boll set and lint yield. The effect of water delivered through three different irrigation applicators (spray above canopy, spray below canopy and LEPA or drag socks) on boll set, lint yield and fiber quality of irrigated cotton was evaluated. Lint yield and the average number of bolls per plant were not affected by the type of applicator used (P<0.05, LSD). However, lint yield was 9.9% less in the spray above canopy applicator treatment than the spray below canopy and LEPA treatments. The type of applicator used did not affect fiber quality

    Fully three-dimensional sound speed-corrected multi-wavelength photoacoustic breast tomography

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    Photoacoustic tomography is a contrast agent-free imaging technique capable of visualizing blood vessels and tumor-associated vascularization in breast tissue. While sophisticated breast imaging systems have been recently developed, there is yet much to be gained in imaging depth, image quality and tissue characterization capability before clinical translation is possible. In response, we have developed a hybrid photoacoustic and ultrasound-transmission tomographic system PAM3. The photoacoustic component has for the first time three-dimensional multi-wavelength imaging capability, and implements substantial technical advancements in critical hardware and software sub-systems. The ultrasound component enables for the first time, a three-dimensional sound speed map of the breast to be incorporated in photoacoustic reconstruction to correct for inhomogeneities, enabling accurate target recovery. The results demonstrate the deepest photoacoustic breast imaging to date namely 48 mm, with a more uniform field of view than hitherto, and an isotropic spatial resolution that rivals that of Magnetic Resonance Imaging. The in vivo performance achieved, and the diagnostic value of interrogating angiogenesis-driven optical contrast as well as tumor mass sound speed contrast, gives confidence in the system's clinical potential.Comment: 33 pages Main Body, 9 pages Supplementary Materia

    Effect of Tillage and Planting Date on Seasonal Abundance and Diversity of Predacious Ground Beetles in Cotton

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    A 2-year field study was conducted in the southern High Plains region of Texas to evaluate the effect of tillage system and cotton planting date window on seasonal abundance and activity patterns of predacious ground beetles. The experiment was deployed in a split-plot randomized block design with tillage as the main-plot factor and planting date as the subplot factor. There were two levels for each factor. The two tillage systems were conservation tillage (30% or more of the soil surface is covered with crop residue) and conventional tillage. The two cotton planting date window treatments were early May (normal planting) and early June (late planting). Five prevailing predacious ground beetles, Cicindela sexguttata F., Calosoma scrutator Drees, Pasimachus spp., Pterostichus spp., and Megacephala Carolina L. (Coleoptera: Carabidae), were monitored using pitfall traps at 2-week intervals from June 2002 to October 2003. The highest total number of ground beetles (6/trap) was observed on 9 July 2003. Cicindela sexguttata was the dominant ground dwelling predacious beetle among the five species. A significant difference between the two tillage systems was observed in the abundances of Pterostichus spp. and C. sexguttata. In 2002. significantly more Pterostichus spp. were recorded from conventional plots (0.27/trap) than were recorded from conservation tillage plots (0.05/trap). Significantly more C. sexguttata were recorded in 2003 from conservation plots (3.77/trap) than were recorded from conventional tillage plots (1.04/trap). There was a significant interaction between year and tillage treatments. However, there was no significant difference in the abundances of M. Carolina and Pasimachus spp. between the two tillage practices in either of the two years. M. Carolina numbers were significantly higher in late-planted cotton compared with those observed in normal-planted cotton. However, planting date window had no significant influence on the activity patterns of the other species. Ground beetle species abundance, diversity, and species richness were significantly higher in conservation tillage plots. This suggests that field conditions arising from the practice of conservation tillage may support higher predacious ground beetle activity than might be observed under field conditions arising from conventional tillage practices

    Effect of Irrigation Application Devices on Boll Set, Cotton Yield and Fiber Quality

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    Previous research concluded that water sprayed above the canopy on open flowers interrupted pollination causing flower drop and subsequent reduction in boll set and lint yield. The effect of water delivered through three different irrigation applicators (spray above canopy, spray below canopy and LEPA or drag socks) on boll set, lint yield and fiber quality of irrigated cotton was evaluated. Lint yield and the average number of bolls per plant were not affected by the type of applicator used (P<0.05, LSD). However, lint yield was 9.9% less in the spray above canopy applicator treatment than the spray below canopy and LEPA treatments. The type of applicator used did not affect fiber quality

    Concentrations of dissolved and particulate manganese in waters of the Southwest Pacific

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    Concentrations of dissolved and particulate manganese in relation with organic matter in waters of the Southwest Pacific are under consideration

    Subsurface drip irrigation: status of the technology in 2010

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    Subsurface drip irrigation (SDI), although a much smaller fraction of the microirrigated land area than surface drip irrigation, is growing at a much faster rate and is the subject of considerable research and educational efforts in the U.S. This article discusses the growth of SDI, highlights some of the research and extension efforts, and points out some of the challenges to SDI adoption and some of the future opportunities for SDI

    Chemical composition of organic matter in ocean sediments

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    Group composition of organic matter in recent ocean sediments with high Corg content has been studied in detail. It has been shown that organic matter in sediments with Corg content greater than 4% is present in the very earliest stages of transformation. Group composition of amino acids is practically similar to that of their main producer, namely phytoplankton. Organic matter of sediments with Corg content below 4% is, from this standpoint, more transformed and is close to organic matter in usual type sediments with similar Corg content
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