University of Arkansas System

Groundwater contamination has prompted the Environmental Protection Agency to consider restricting atrazine use, highlighting the need for alternative preemergence herbicides in grain sorghum. Research was conducted in 2023 and 2024 to evaluate grain

In the state of Arkansas, U.S.A., rice ( Oryza sativa) yield has been affected by a disease caused by the fungus Cercospora janseana. Previously considered to have low impact, its resurgence has led to noticeable yield losses. Moreover, symptoms have been observed on different plant structures. This report evaluates the use of host genetic resistance and the fungicide Tilt at different application timings to control Cercospora in rice. The experiment was conducted in the 2024 growing season in Colt, AR, using three cultivars recommended for the region. The use of the fungicide propiconazole at different timings during the boot stage in cultivars PVL03, CLL19, and RT7521FP allowed for inferences about the integration of host resistance and fungicide application. The results of this study provide important insights into the understanding and effective management of C. janseana in rice.

1. Anthropogenic food subsidies can have profound influences on wildlife behavior and health, including exposure to parasites. In many host-macroparasite systems, parasite exposure is tied to foraging behavior, but how different distributions of food subsidy shape macroparasite encounter and population-level impacts is poorly understood. 2. Here we modify a mathematical model of macroparasite transmission to explore how food subsidies could change parasite encounter rates and between-host variation in parasite burdens, reflecting changes in host foraging and conspecific overlap. 3. Hosts experience the highest average parasite abundance, and associated reductions in population size, when food subsidies increase and homogenize parasite encounter rates, for example when hosts center their home ranges on a point food source and overlap with many conspecifics. Conversely, hosts experience the lowest parasite abundance and impacts when subsidies result in lower and more heterogeneous parasite encounter rates, for example when multiple, patchily-distributed subsidies subdivide host populations and increase host commute times to food at the expense of time spent foraging. Even when resources affect other processes such as improving host immunity or fecundity, the overall effect of subsidies on infection is more strongly driven by changes in parasite encounter rates through altered foraging behavior. These patterns are robust to different effect sizes of resource subsidy on foraging and non-foraging parameters. 4. The finding that host foraging behavior strongly influences infection outcomes in environmentally-acquired parasites has implications for the provisioning of wildlife for recreation, conservation, and management. We advocate for distributing food subsidies in ways that reduce artificial aggregation of hosts and the time animals spend at feeding stations, or that reduce environmental parasite encounters while feeding.

Small ruminants are adapted to a variety of environments and cultures as they are raised worldwide to convert forages into meat, milk, and fiber. Nutrition, which is the interrelated process of assimilating and using nutrients, is essential for the health and productivity of sheep and goats. Proper nutrition ensures adequate growth, reproduction, and immune system function. However, gastrointestinal nematodes (GIN) can be a significant threat to small ruminants, especially in warm, humid environments, causing production and economic losses. This chapter outlines the general aspects and role of nutrition in small ruminant health, production, and welfare, exploring the impacts of GIN parasitism on nutrition and metabolism, and how diet manipulation can be used as a tool to increase both resistance and resilience of small ruminants to GIN infections.

Damping-off, caused by the fungal pathogen Rhizoctonia solani, is a soilborne disease that impacts rice fields. This pathogen infects young seedlings, causing injuries, lack of vigor, seedling death, and reduced plant stands. Delays in seedling emergence due to adverse conditions tend to increase the severity of damping-off. This report evaluates the efficacy of seed treatment programs for managing a rice seedling disease in Arkansas. The trial was carried out in 2023 in Stuttgart, AR, on the Clearfield rice ( Oryza sativa L.) variety ‘CL163’. Results from this trial will assist rice growers in selecting effective fungicide combinations for managing rice seedling diseases.

Heat stress (HS) has long posed a significant challenge to the poultry industry due to its adverse effects, such as depressed feed intake, decreased growth performance, and increased water consumption. Water efficiency (WE, conversion of water intake into body weight gain), although often neglected, is a key economic and production trait that is significantly affected by HS. Recently, we selected two broiler lines for high WE (HWE) and low WE (LWE) and showed a differential hypothalamic expression of genes involved in water homeostasis regulation. As the gut also plays a significant role in water absorption, the present study aimed to determine the effect of chronic HS on duodenal barrier integrity in LWE and HWE broilers. Male HWE and LWE chicks (240 chicks/line) were individually wing-banded for line identification, weighed, and placed in 12 controlled environmental chambers (2 pens/chambers). On day 29, birds were subjected to thermoneutral conditions (TN, 25 °C) or cyclic HS conditions (HS, 36 °C for 9 h/day from 9:00 a.m. to 6:00 p.m.) (120 birds/line/environment) for 3 weeks. On day 49, duodenal tissues were collected for histological, biochemical, and molecular analyses. Hematoxylin and eosin (H&E) staining revealed that HS significantly reduced villus height in the duodenum. Further analysis using qPCR showed that the mRNA expressions of intestinal barrier integrity-related genes, including claudins (CLDN1, 4, 5, 8, 16, and 22), PALS1-associated tight junction protein (PATJ), gap junction alpha 1 and 3 (GJA1/3), cadherin 2 (CDH2), and catenin alpha 2 (CTNNA2), were significantly upregulated by HS, and this effect was more pronounced in the HWE line than in its LWE counterpart. The findings of this study indicate that HS induces duodenal morphometric alterations. Based on the reduced serum fluorescein isothiocyanate-dextran (FITC-D) levels previously reported in the HWE line, the increased abundances of CLDN, PATJ, GJA1, CDH2, and CTNNA2 mRNAs in the HWE line suggest an enhancement of its duodenal barrier integrity for better nutrient and water absorption and, consequently, better growth efficiency.

The gate driver is crucial for silicon carbide (SiC) based power electronics, by directly governing switching speed, efficiency, and EMI performance, while it also ensures reliability through protection against false turn-on, overvoltage, and short-circuit events. This paper presents a simplified gate driver layout for SiC-based medium-voltage power modules. The design employs dual gate driver ICs per switching position to supply the required gate current, thereby enhancing the switching performance of the power module. The proposed gate driver adopts a two-level hierarchical PCB design: one level integrates the driver components closely with the SiC dies for reduced gate loop inductances and fast switching speed, while the other provides high isolation to support medium-voltage operation. The connections from the gate driver to the power module are provided through co-axial pins for improved noise immunity. The proposed gate driver architecture was evaluated using a discrete half-bridge switch setup, demonstrating high switching performance with measured slew rates of 104.23 V/ns for turn-on and 152.38 V/ns for turn-off.

The United States plays a significant role in the global table grape industry and is among the top producers and exporters worldwide. The ∼US$1.7 billion US fresh-market industry is dominated by Vitis vinifera cultivars, with 94% of US production in California. However, recent advances in developing Vitis–Muscadinia hybrids with consumer-favorable traits might be a viable alternative for a more resilient US industry. The genus Vitis has two subgenera: Vitis (bunch grapes grown worldwide) and Muscadinia (muscadines native to the US Southeast). An online survey was done to determine consumer ( n = 950) preferences for US fresh-market table grapes (bunch and muscadine) and attributes. A discrete choice experiment was used to elicit willingness-to-pay (WTP) from the participants for six table grape attributes including price (US$2, 3, 4, 5, or 6), flavor (strong or mild), texture (soft or firm/crisp), size (small, medium, or large), seed (none or present), and color (purple/black, pink/red, or light/green). The survey had four randomized survey blocks: 1) discrete choice set 1, 2) discrete choice set 2, 3) fruit purchasing habits, and 4) demographic characteristics. Participants were willing to pay US$6.51 more per pound for bunch grapes and US$5.57 more per pound for muscadine grapes compared with the base attribute (neither). Consumers had no preference for size or flavor of the grapes. Consumers were willing to pay US$3.59 more for seedless grapes vs. seeded and US$1.44 more per pound for a firm-textured grape vs. a soft one. Consumer WTP for pink/red grapes was US$0.94 less per pound than green/light grapes and US$0.69 less for purple/black grapes than green/light grapes. In overall ranking, freshness was the most important attribute, followed by flavor, price, seed presence, texture, color, and size. There was clear interest with US consumers for both bunch and muscadine grapes, with mild-flavored and firm-textured grapes preferred. Bunch grapes were appreciated by participants from all US regions (Southeast, Northeast, Pacific, Midwest, and Southwest), and there was interest in muscadine grapes in most regions. Some consumers preferred muscadine grapes, indicating the potential for expanded commercial markets. This interest was most strongly found in the US Southeast, where muscadines are native, and is relevant for the Northeast and potential new markets in the Midwest. Although the US table grape industry is influenced by import dynamics, environmental impacts, pests/disease pressures, and evolving consumer preferences, understanding current values will help guide future cultivar innovations.

Abstract Soil pH and liming recommendations that address the soils, crops, and liming materials have been developed and adopted by land grant universities since the early 20th century. We inventoried land grant institution soil pH and lime requirement (LR) measurement methods for 1980 and 2020 and examined differences in lime rate recommendations for six reference soils using a survey developed by members of the Fertilizer Recommendation Support Tool initiative. Laboratory analysis for six acidic soils with a range of properties was shared with scientists requesting a lime recommendation for each, assuming a 0‐ to 15‐cm soil depth, 6.5 target pH, and lime material having 100% effective calcium carbonate equivalence. Soil pH methods, LR methods, and lime rate recommendations were documented for 48, 41, and 34 states, respectively. The most widely used pH method was a 1:1 soil–water ratio (34 states, 71%). Thirty‐one states use one or more buffer solutions to determine LR with the most widely used being the Sikora (10 states), Mehlich (10 states), and Shoemaker, McLean, and Pratt (nine states) buffers. Forty lime rate recommendations from 34 states for each soil were summarized with median rates ranging from 2242 to 9079 kg ha −1 and coefficients of variation ranging from 41% to 73%. The reasons for high LR variability are likely due to different calibrations as no strong trends for LR method or region were observed. Efforts are needed to develop and harmonize lime recommendations to provide accurate and transparent guidance, especially for states sharing common soils and boundaries.

Low-moisture food persistent bacterial populations (LMF PBPs) may be responsible for pathogen harborage in LMF processing environments, resulting in outbreaks and recalls. To address this issue, industry requires a surrogate to understand the survivability of LMF PBP and perform in-plant validation studies to reduce the level of this pathogen to an acceptable level. Hygienic controls for the LMF industry must be tailored to different equipment, environments, and food types. In-plant validations with a surrogate would assist with evaluating the efficacy of sanitation protocols that eliminate LMF PBPs and harborage. This study explored surrogates for Salmonella LMF PBP to provide tools for challenge studies to eliminate LMF PBPs from stainless-steel surfaces. Three surrogates (Escherichia coli MP 26, Enterococcus faecium, Pediococcus acidilactici) were evaluated for similarity to a Salmonella LMF PBP in nonfat dried milk (NFDM) formed on stainless steel coupons stored at 30% or 70% relative humidity (RH) at 25°C. Coupons were prepared with a previously established method to form an LMF PBP (0.5g of NFDM, 0.4mL culture). Microbial survival was enumerated at intervals (0, 1, 3, 5, and 7days) using standard plating techniques. An ANOVA and Tukey's HSD tests were used to compare log reductions to identify suitable surrogates. E. faecium exhibited higher survival trends that were most similar to Salmonella, with no significant differences in log reductions (p>0.05). In contrast, E. coli surrogate panel and P. acidilactici showed significantly greater reductions, making them unsuitable surrogate candidates for Salmonella. Matrices and RH interactions influenced survival, but E. faecium consistently mirrored Salmonella behavior. E. faecium was similar but hardier than Salmonella LMF PBPs and could be used in processing environments for challenging and validating sanitation protocols.