and detailed reviews of X-ray CT have been provided by Pires et al. (2010) , Stock (2008) , and Wildenschild et al. (2002) . A CT scan involves passing monochromatic X-ray beams with incident intensity I 0 through a sample of thickness τ, resulting
age of the seeds nor their storage conditions were indicated. Visual observations along with SEM to examine the surface of seeds may be useful to distinguish full from empty seeds. Therefore, X-ray scanning technology can be applied to evaluate images
are very small and using the floating technique for 16 h or longer facilitates separation of full and mature seeds from immature and empty seeds on a large scale, especially when X-ray scanning is not available. Immersing Casuarina equisetifolia
(see Fang et al., 2012 for a comprehensive review). High-resolution X-ray CT scanning offers spatiotemporal imaging of root development ( Lontoc-Roy et al., 2006 ; Tracy et al., 2010 ). Primary complexities with this method include root organ (root
Abstract
Druse crystals observed with light and scanning electron microscopy in root tissue of Ipomoea batatas (L.) Lam. cv. Jewel were identified as calcium oxalate monohydrate by use of energy-dispersive X-ray analysis and X-ray diffraction techniques. Crystals occurred primarily in the parenchyma cells of the edible root.
the ICAP measurements. Another method to study surface distribution of chemical elements, energy-dispersive x-ray spectrometry (EDS) coupled to the scanning electron microscope (SEM), has also been used to measure elements in plant tissue ( LeRiche et
Near infrared (NIR) absorption spectrometry and X-ray computed tomography (CT) were used to nondestructively determine the presence of section drying, an internal disorder in tangerines (Citrus reticulata Blanco, cv. Dancy). X-ray CT scan images clearly differentiated areas with section drying from healthy sections of the fruit. Delineation was due to differences in X-ray absorption resulting from lower tissue density and water content in vesicles having the disorder. Second derivative NIR optical density values at 768 and 960 nm correlated strongly with the presence or absence of section drying, indicating that NIR optical properties of vesicles with section drying differed from those without the disorder. These results suggest that, compared with X-ray—based techniques, NIR absorption spectroscopy could be a less expensive, safe, and rapid method for the nondestructive sensing of section drying in citrus fruit.
Abstract
Excellent, though limited, use has been made of electron optical equipment in the field of horticulture. The increasing availability and the refinements in such instruments as the electron microprobe X-ray analyzer, the scanning electron microscope and the transmission electron microscope have made them invaluable tools for the horticultural scientist. In an effort to extend the use of such equipment this paper discusses the operation, present and potential applications, sample preparation techniques and problems, and a glimpse of the future of electron optical equipment in horticulture.
One small-plotfield and five container experiments were conducted to evaluate sheep wool-wastes and human hair-wastes as soil amendments and nutrient sources for high-value crops. Overall, the wool-waste or hair-waste addition to soil: 1) increased yields from basil, garden sage, peppermint, valerian, thorn apple, marigold, foxglove, and swiss chard; 2) increased the amount of secondary metabolites (such as essential oils and alkaloids); 3) increased NH4-N and NO3-N in soil; 4) increased total N (and protein) content in plant tissue; 5) did not affect soil microbial biomass; and 6) decreased mycorrhizae colonization of plant roots. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyses indicated that some of the wool and hair in soil from the container and field experiments (after two field seasons and several harvests) retained its original structure, retained a significant amount of S and some N, and was not fully decomposed. Our results indicate that single addition of wool or hair-waste of 0.33% by weight to soil would support two to five harvests or crops, without addition of other fertilizers, and may improve soil biological and chemical characteristics.
Container and field experiments were conducted to evaluate sheep wool wastes and human hair wastes as soil amendments and nutrient sources for high-value crops. Overall, wool-waste or hair-waste additions to soil increased yields from basil, garden sage, peppermint, valerian, thorn apple, marigold, foxglove, and swiss chard; increased the amount of secondary metabolites (such as essential oils and alkaloids); increased NH4-N and NO3-N in the soil; and increased total N (and protein) content in plant tissue. The wool-waste or hair-waste additions did not affect soil microbial biomass, but decreased mycorrhizae colonization of plant roots. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses indicated that some of the wool and hair in soil from the container and field experiments (after two field seasons and several harvests) retained its original structure, a significant amount of S, some N, and was not fully decomposed. Results from this study suggest that wool and hair wastes can be used as soil amendment and nutrient source for high-value container or field crops.