174 Forage Production and Nutritive Value of Alfalfa-bermudagrass Mixtures Managed Under Contrasting Defoliation Strategies in the Southeast US

Incorporation of alfalfa (Medicago sativa) into bermudagrass pastures improves forage quality and decreases the reliance on synthetic nitrogen fertilizer. The objective of this study was to determine forage mass (FM), nutritive value (NV), and botanical composition of ‘Bulldog 805’ alfalfa and ‘Tifton 85’ bermudagrass (T85; Cynodon dactylon) mixtures managed under three defoliation strategies: 1) hay production (H), 2) grazing (G) or 3) dual-purpose (DP) use. The study was conducted in two locations (Headland, AL and Tifton, GA) using a randomized complete block design with two replicates. In spring 2020, grazed plots were divided in four strips and every 7-d, animals were rotated to a new strip and stocking rate was adjusted. Under DP, plots were grazed until mid-July, then forage was harvested in late August. For H plots, forage was harvested every 28 to 35-d. Forage samples were collected prior defoliation to determine FM and on grazed periods, pre- and post-grazing samples and disk meter measurements were collected. Nutritive value responses were determined using near-infrared spectroscopy. There was no effect of defoliation strategy on FM (P = 0.604; mean 3471 kg DM/ha). Greater FM (P = 0.002) was observed in July and August than June (3531 and 3976 vs 2905 kg DM ha-1, SE= 263). This response was associated with an up to 40% increase of T85 proportion in the mixture (P = 0.001). Alfalfa percentage was 78% greater for DP than G (P = 0.029). There were no differences among treatments for NV responses (P > 0.05). Among defoliation periods, crude protein, neutral detergent fiber and acid detergent fiber concentrations ranged from 14 to 22%, 45 to 58% and 28 to 35%, respectively. These preliminary results demonstrate multi-use options for this mixture in the region while aiming for increased forage nutritive value, and extended growing season, and sustainability of forage-livestock systems.

The Early Evening Transition in Southeastern US Tornado Environments

The response of severe local storms to environmental evolution across the early evening transition (EET) remains a forecasting challenge, particularly within the context of the Southeast US storm climatology, which includes the increased presence of low-CAPE environments and tornadic non-supercell modes. To disentangle these complex environmental interactions, Southeast severe convective reports spanning 2003-2018 are temporally binned relative to local sunset. Sounding-derived data corresponding to each report are used to characterize how the near-storm environment evolves across the EET, and whether these changes influence the mode, frequency, and tornadic likelihood of their associated storms. High-shear, high-CAPE (HSHC) environments are contrasted with high-shear, low-CAPE (HSLC) environments to highlight physical processes governing storm maintenance and tornadogenesis in the absence of large instability. Lastly, statistical analysis is performed to determine which aspects of the near-storm environment most effectively discriminate between tornadic (or significantly tornadic) and nontornadic storms towards constructing new sounding-derived forecast guidance parameters for multiple modal and environmental combinations. Results indicate that HSLC environments evolve differently than HSHC environments, particularly for non-supercell (e.g., quasi-linear convective system) modes. These low-CAPE environments sustain higher values of low-level shear and storm-relative helicity (SRH) and destabilize post-sunset – potentially compensating for minimal buoyancy. Furthermore, the existence of HSLC storm environments pre-sunset increases the likelihood of non-supercellular tornadoes post-sunset. Existing forecast guidance metrics such as the significant tornado parameter (STP) remain the most skillful predictors of HSHC tornadoes. However, HSLC tornado prediction can be improved by considering variables like precipitable water, downdraft CAPE, and effective inflow base.

Homeward bound: canopy cover and species identity influence non-breeding season homing success and speed in forest birds

Background Efficient and safe movement is fundamental for wild birds to thrive in their environments. For arboreal forest animals, especially birds, canopy cover has a large impact on birds’ daily movements and is a crucial component of conservation strategies seeking to retain avian population in disturbed or urban habitats. Methods We translocated woodland bird species utilizing different forest strata during two non-breeding seasons in Gainesville, FL, USA. We used linear model and generalized linear model to examine the effects of canopy cover and species identity on homing success and speed. Results Among our study species of Tufted Titmouse (Baeolophus bicolor), Carolina Chickadee (Poecile carolinensis), and Northern Cardinal (Cardinalis cardinalis), we found that Carolina Chickadees and Tufted Titmice were more likely to return than Northern Cardinals. Among birds that successfully returned, homing speed is significantly affected by forest canopy cover and species identity (titmice had higher homing speed than cardinals). Birds return much faster in landscape with higher canopy cover. Conclusions This study presented evidence of species identity’s effect on homing success and speed in common feeder bird species in Southeast US and provided further evidence that bird movements in the suburban land cover are constrained by low canopy cover.

A retrospect on the US apparel industry: expert predictions and reality data

Purpose In 1978, the once powerful US apparel industry was on the cusp of change, and the consulting firm KSA conducted a Delphi survey of apparel executives’ predictions into the 2000s. The purpose of this paper is to compare actual changes over the subsequent decades with these 1978 expert predictions and explore the accuracy/inaccuracy of these “educated guesses” (KSA, 1978, p. 1). Design/methodology/approach The chorographic method was used to analyze the report and document historical data. Chorography is “concerned with significance of place, regional characterization, [and] local history […]” (Rohl, 2012, p.1) and includes contextual settings and researcher input. Primary data were examined during each decade and included: industry literature, government documents and labor data. The researchers used content analysis to reduce and organize data. Findings Findings cover three decades of Southeast US apparel industry data including imports, employment, number of plants, size of plants and productivity. Predictions were inaccurate about imports, predicted to be minor in comparison with domestic production, which they actually surpassed. Predicted decrease in employment was similar to actual decrease but reasons were inaccurate. Change in number and size of plants were over-predicted and under-predicted. Reasons given by experts were automation and government intervention; in actuality, limited automation occurred with insignificant impact in contrast to outsourcing, which decimated employment in US plants. Steady increase in productivity was predicted when productivity often decreased. Originality/value Previous studies focus on the textile sector; studies of the apparel sector tend to be regional or topical. This study is more expansive and provides insight into predictions and changes made in the US apparel industry at a critical time in its near demise. With the current climate of global change and increased market uncertainty, insights from this study may provide direction for rethinking of the domestic apparel industry for the USA and other developed countries.

Genetic differentiation of Xylella fastidiosa following the introduction into Taiwan

The economically important plant pathogen Xylella fastidiosa has been reported in multiple regions of the globe during the last two decades, threatening a growing list of crops and industries. Xylella fastidiosa subspecies fastidiosa causes disease in grapevines (Pierce's disease of grapevines, PD), a current problem in the United States (US), Spain, and Taiwan. We studied PD-causing subsp. fastidiosa populations and compared the genome sequences of 33 isolates found in Central Taiwan with 171 isolates from the US and two from Spain. Phylogenetic relationships, haplotype network, and genetic diversity analyses confirm that subsp. fastidiosa was recently introduced into Taiwan from the Southeast US (i.e., the PD-I lineage in Georgia based on available data). Recent core genome recombination events were detected among introduced subsp. fastidiosa isolates in Taiwan and contributed to the development of genetic diversity, particularly in the Houli District of Taichung City in Central Taiwan. Unexpectedly, despite comprehensive sampling of all regions with high PD incidences in Taiwan, the genetic diversity observed include contributions through recombination from unknown donors, suggesting that higher diversity exists in the region. Nevertheless, no recombination event was detected between X. fastidiosa subsp. fastidiosa and the endemic sister species Xylella taiwanensis. In summary, this study improved our understanding of the genetic diversity of PD-causing subsp. fastidiosa after invasion to a new region.