Due to the great technological importance of the microstructure of kaolinite, characterizing its evolution during dry milling of kaolin and analyzing the microstructural information obtained from different methods were the main aims of this work. The microstructural alteration of kaolinite is evaluated by X-ray diffraction and electron microscopy methods, comparing the results obtained and analyzing the correlations between them. The Warren-Averbach and Voigt-function methods of X-ray diffraction microstructural analysis have been applied successfully to the study of the effects of two different, vibrating-cup dry-milling configurations in the microstructure of kaolinite from the reflections corresponding to (001) diffracting planes. The crystallite-size estimates obtained from the two methods correlate well. Field emission scanning electron microscopy measurements of kaolinite particle thickness are in good agreement with the crystallite size estimated by the two methods. The Warren-Averbach method also provided estimates of the contribution to line broadening. Vibrating-cup milling has been proved to be a more efficient method of strain comminution of kaolinites than other milling techniques, reaching extensive microstructural degradation within seconds.

Following large-scale herbicide spraying and burning on Assateague Island, a barrier bar island located in Maryland and Virginia, the invasive common reed (Phragmites australis) was largely reduced from vast monocultures to less dense patches interspersed within maritime shrublands. To improve the control of these remnant/reemerging infestations and limit further nontarget damage, we tested three new treatments: mechanical cutting followed by dripping imazapyr onto stems, cutting followed 2 wk later by the foliar spraying of regrowth, and simple cutting with and without the removal of Phragmites litter. All herbicide treatments and cutting paired with litter removal significantly reduced Phragmites coverage (P ≤ 0.01) when compared with untreated controls. Native plant coverage was significantly greater after the cut-stem treatment than after traditional foliar spraying (P ≤ 0.01) because of the former's reduced herbicide use and more direct contact limited to Phragmites stems; native coverage was also greater after litter removal than when litter remained (P ≤ 0.001). Cutting followed by stem applications of herbicide is an effective means of treating scattered common reed stands in sensitive habitats, and litter removal after cutting can provide native vegetation with an advantage at recolonization.

The nonnative biotype of common reed has invaded wetlands in many states including Nebraska, especially along the Platte River from Wyoming to the eastern edge of Nebraska. Therefore, three studies (disking followed by herbicide, mowing followed by herbicide, and herbicide followed by mechanical treatment) were conducted for 3 yr (2008 to 2010) at three locations in Nebraska. The objective was to evaluate common reed control along the Platte River using an integrated management approach based on herbicides (glyphosate or imazapyr), mowing, and disking, either applied alone or in combination. The level of weed control was determined by visual rating, percent flowering, and stem density. On the basis of visual rating, disking and mowing used alone provided common reed control for only a few months. However, the control was significantly prolonged (e.g., at least three seasons) when disking and mowing were combined with herbicide applications. Disking followed by herbicide and mowing followed by herbicide significantly reduced flowering and plant densities (P = 0.0001) compared to the untreated check. These results suggest that a combination of weed control methods has potential to control common reed.