Autochthonous Ascariasis, Mississippi, USA.

We describe a case of a 2-year-old child who expelled a single adult female Ascaris lumbricoides worm. The patient is from a rural county in Mississippi, USA, with no reported travel outside of the United States. The caregivers in the home practice good sanitation. Exposure to domestic pigs is the likely source of infection.

Disparities in access to appointments for contraceptive services among Black, Hispanic, White, and recently incarcerated women in Alabama, Louisiana, and Mississippi.

OBJECTIVE: To measure differences in access to contraceptive services based on history of incarceration and its intersections with race/ethnicity and insurance status. DATA SOURCES AND STUDY SETTING: Primary data were collected from telephone calls to physician offices in Alabama, Louisiana, and Mississippi in 2021. STUDY DESIGN: We deployed a field experiment. The outcome variables were appointment offers, wait days, and questions asked of the caller. The independent variables were callers' incarceration history, race/ethnicity, and insurance. DATA COLLECTION METHODS: Using standardized scripts, Black, Hispanic, and White female research assistants called actively licensed primary care physicians and Obstetrician/Gynecologists asking for the next available appointment for a contraception prescription. Physicians were randomly selected and randomly assigned to callers. In half of calls, callers mentioned recent incarceration. We also varied insurance status. PRINCIPAL FINDINGS: Appointment offer rates were five percentage points lower (95% CI: -0.10 to 0.01) for patients with a history of incarceration and 11 percentage points lower (95% CI: -0.15 to -0.06) for those with Medicaid. We did not find significant differences in appointment offer rates or wait days when incarceration status was interacted with race or insurance. Schedulers asked questions about insurance significantly more often to recently incarcerated Black patients and recently incarcerated patients who had Medicaid. CONCLUSIONS: Women with a history of incarceration have less access to medical appointments; this access did not vary by race or insurance status among women with a history of incarceration.

SEROPREVALENCE OF TOXOPLASMA GONDII INFECTION IN PIGS FROM SOUTHWESTERN MISSISSIPPI.

Toxoplasma gondii infection of swine is a potential public health concern because it can be acquired by humans through the handling and consumption of contaminated raw meat. Infections in immunocompromised individuals and fetuses are the most severe and these individuals are most likely to develop clinical toxoplasmosis. Since Mississippians consume a lot of pork, there was a significant need to know the extent to which it poses a health problem in the State. This study focused on the southwestern region of Mississippi. Between July 2003 and March 2004, blood samples were collected from slaughterhouses in southwestern Mississippi and the Alcorn State University swine farm in Churchill, Mississippi. The collected blood samples were centrifuged and the sera were collected, labeled, and stored in a freezer at -20 C. The modified agglutination test was performed at dilutions of 1:25, 1:50, and 1:500. A titer of 25 was considered seropositive. Of a total of 302 samples tested, 48 (16%) were positive at a titer of 25; 29 (10%) were positive at 50; 11 (4%) were positive at 500. The seroprevalence of T. gondii in pigs in southwestern Mississippi is not as high as previous studies done in Mississippi. This could be attributed to the sample size. However, the potential for infection still exists.

Risk Factors for Severe Maternal Morbidity Among Women Enrolled in Mississippi Medicaid.

Importance: Mississippi has one of the highest rates of severe maternal morbidity (SMM) in the US, and SMMs have been reported to be more frequent among Medicaid-insured women. A substantial proportion of pregnant women in Mississippi are covered by Medicaid; hence, there is a need to identify potential risk factors for SMM in this population. Objective: To examine the associations of health care access and clinical and sociodemographic characteristics with SMM events among Mississippi Medicaid-enrolled women who had a live birth. Design, Setting, and Participants: A nested case-control study was conducted using 2018 to 2021 Mississippi Medicaid administrative claims database. The study included Medicaid beneficiaries aged 12 to 55 years who had a live birth and were continuously enrolled throughout their pregnancy period and 12 months after delivery. Individuals in the case group had SMM events and were matched to controls on their delivery date using incidence density sampling. Data analysis was performed from June to September 2022. Exposure: Risk factors examined in the study included sociodemographic factors (age and race), health care access (distance from delivery center, social vulnerability index, and level of maternity care), and clinical factors (maternal comorbidity index, first-trimester pregnancy-related visits, and postpartum care). Main Outcomes and Measures: The main outcome of the study was an SMM event. Adjusted odds ratio (aORs) and 95% CIs were calculated using conditional logistic regression. Results: Among 13 485 Mississippi Medicaid-enrolled women (mean [SD] age, 25.0 [5.6] years; 8601 [63.8%] Black; 4419 [32.8%] White; 465 [3.4%] other race [American Indian, Asian, Hispanic, multiracial, and unknown]) who had a live birth, 410 (3.0%) were in the case group (mean [SD] age, 26.8 [6.4] years; 289 [70.5%] Black; 112 [27.3%] White; 9 [2.2%] other race) and 820 were in the matched control group (mean [SD] age, 24.9 [5.7] years; 518 [63.2%] Black; 282 [34.4%] White; 20 [2.4%] other race). Black individuals (aOR, 1.44; 95% CI, 1.08-1.93) and those with higher maternal comorbidity index (aOR, 1.27; 95% CI, 1.16-1.40) had higher odds of experiencing SMM compared with White individuals and those with lower maternal comorbidity index, respectively. Likewise, an increase of 100 miles (160 km) in distance between beneficiaries' residence to the delivery center was associated with higher odds of experiencing SMM (aOR, 1.14; 95% CI, 1.07-1.20). Conclusions and Relevance: The study findings hold substantial implications for identifying high-risk individuals within Medicaid programs and call for the development of targeted multicomponent, multilevel interventions for improving maternal health outcomes in this highly vulnerable population.

Long-term trajectory of ozone impact on maize and soybean yields in the United States: A 40-year spatial-temporal analysis.

Understanding the long-term change trends of ozone-induced yield losses is crucial for formulating strategies to alleviate ozone damaging effects, aiming towards achieving the Zero Hunger Sustainable Development Goal. Despite a wealth of experimental research indicating that ozone's influence on agricultural production exhibits marked fluctuations and differs significantly across various geographical locations, previous studies using global statistical models often failed to capture this spatial-temporal variability, leading to uncertainties in ozone impact estimation. To address this issue, we conducted a comprehensive assessment of the spatial-temporal variability of ozone impacts on maize and soybean yields in the United States (1981-2021) using a geographically and temporally weighted regression (GTWR) model. Our results revealed that over the past four decades, ozone pollution has led to average yield losses of -3.5% for maize and -6.1% for soybean, translating into an annual economic loss of approximately $2.6 billion. Interestingly, despite an overall downward trend in ozone impacts on crop yields following the implementation of stringent ozone emission control measures in 1997, our study identified distinct peaks of abnormally high yield reduction rates in drought years. Significant spatial heterogeneity was detected in ozone impacts across the study area, with ozone damage hotspots located in the Southeast Region and the Mississippi River Basin for maize and soybean, respectively. Furthermore, we discovered that hydrothermal factors modulate crop responses to ozone, with maize showing an inverted U-shaped yield loss trend with temperature increases, while soybean demonstrated an upward trend. Both crops experienced amplified ozone-induced yield losses with rising precipitation. Overall, our study highlights the necessity of incorporating spatiotemporal variability into assessments of crop yield losses attributable to ozone pollution. The insights garnered from our findings can contribute to the formulation of region-specific pollutant emission policies, based on the distinct profiles of ozone-induced agricultural damage across different regions.

Social, Structural, Behavioral, and Clinical Barriers Influencing Pre-exposure Prophylaxis (PrEP) Use Among Young Black Men Who Have Sex with Men in the South: A Qualitative Update to a 2016 Study.

Antiretroviral pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV. Despite its promise, PrEP use is low, especially among young Black men who have sex with men (YBMSM). The prevalence of HIV in Mississippi (MS) is among the highest in the United States, with the bulk of new infections occurring amongst YBMSM living in Jackson, MS. We recruited 20 PrEP-eligible YBMSM and 10 clinic staff from MS health clinics between October 2021 and April 2022. Data were collected remotely using in-depth interviews and a brief survey, which lasted approximately 45-60 min. Interview content included PrEP knowledge/experiences, HIV risk perception, and PrEP use barriers and facilitators. Qualitative data were coded then organized using NVivo. Using thematic analysis methodology, data were assessed for current barriers to PrEP use. An array of barriers were identified by participants. Barriers included structural factors (cost of PrEP, lack of discreet clinics, time commitment, competing interests); social factors (unaware of HIV risk, stigma and homophobia, fear that partners would find out about PrEP use, not knowing anyone on PrEP); behavioral factors (sexual risk factors, denial, less priority for prevention vs treatment); and clinical factors (misunderstood side effects, fear PrEP won't work). Significant barriers to PrEP use among YBMSM stem from structural, social, behavioral, and clinical factors. These results will inform intervention efforts tailored to mitigate barriers and improve PrEP uptake among YBMSM in the southern United States.

Harvest for health in survivors of chronic disease: A demonstration project in the Alabama Black Belt and Mississippi Delta Region.

This demonstration project expands upon the Harvest for Health vegetable gardening intervention for cancer survivors by: (i) including survivors of other chronic diseases (i.e. heart disease and diabetes); and (ii) targeting an area with known health inequities (Alabama Black Belt and Mississippi Delta Region). To assess: (i) gardening acceptability (engagement, satisfaction, sustainability, and safety); and (ii) changes over time in health behaviors (fruit and vegetable [F&V] intake, and physical activity) and outcomes (physical performance and anthropometrics). Chronic disease survivors (CDS) were recruited across 15 counties in Alabama and Mississippi and provided with gardening supplies and paired with a master gardener (MG). MGs mentored participants in planning, planting, and maintaining a vegetable garden over a 3-month period. Data collection consisted of an electronic survey (baseline, post-intervention, 6-month follow-up) and community-based physical assessments (baseline and post-intervention). Participants (n = 137; 92% African American; Mage = 65) included individuals with a history of diabetes (56%), heart disease (29%), and cancer (26%). Seventy-five percent of participants engaged in gardening ≥3 times a week. Significant improvements in F&V intake (+0.73, P = .04), physical activity (+49.6, P < .01), and 4 of 7 physical performance measures were observed, while positive trends were seen in others. Eighteen participants withdrew (13% attrition rate). No adverse events occurred. Participants were satisfied with their gardening experience (90%) and were still gardening at 6-month follow-up (85%). Seventy-two percent of participants expanded, or planned on expanding, their garden at 6-month follow-up. Harvest for Health was acceptable and associated with improved health behaviors and outcomes.

In the Alabama Black Belt and Mississippi Delta region of the USA, incidence and mortality rates of high-burden chronic diseases (cancer, cardiovascular disease, and diabetes) are among the highest in the nation. Behavioral risk factors associated with chronic disease include low fruit and vegetable intake and physical inactivity. Vegetable gardening is a holistic approach to improving these health behaviors. Harvest for Health, a mentored home-based vegetable gardening intervention, pairs cancer survivors with master gardener (MG) mentors to guide survivors in planning, planting, and maintaining a vegetable garden. The current demonstration project expands upon Harvest for Health by: (i) including survivors of cardiovascular disease and diabetes (in addition to cancer); and (ii) targeting an area with known health inequities (Alabama Black Belt and Mississippi Delta). One hundred thirty-seven chronic disease survivors (CDS) enrolled in the 3-month demonstration project. Participants were provided gardening supplies for a summer garden and MG mentorship over a 3-month period. Participants engaged in gardening several times a week, reported satisfaction with their gardening experience, and were still gardening at 6-month follow-up. Improvements among CDS were seen in health behaviors (fruit and vegetable intake and physical activity) and physical well-being (physical function battery and weight).

Abortion Clients' Perceptions of Alternative Medication Abortion Service Delivery Options in Mississippi.

OBJECTIVES: We assessed Mississippi abortion clients' perceptions of alternative medication abortion service delivery options that were restricted under state law but available elsewhere. METHODS: We conducted in-depth interviews with medication abortion clients between November 2020 and March 2021 at Mississippi's only abortion facility. We described alternative service delivery models: telemedicine, medications by mail, and follow-up care in their community versus returning to the facility. We asked if participants would be interested in using any of these models, if available, and how use of each model would have changed their abortion experience. We used thematic analysis, organizing codes into common themes based on participants' preferences and concerns for each option. RESULTS: Of the 25 participants interviewed, nearly all (n = 22) expressed interest in at least one option and reported that, had they been available, these would have alleviated cost, travel, and childcare barriers. Many believed these options would further ensure privacy, but a minority thought abortion was too sensitive for telemedicine or were concerned about mailing errors. Participants not interested in the alternative options also feared missing valued aspects of face-to-face care. Most did not return to the facility for follow-up (n = 19), citing financial and logistical barriers. Largely, participants were not interested in obtaining follow-up care in their community, citing concerns about provider judgment, stigma, and privacy. CONCLUSIONS: Mississippi abortion clients were interested in models that would make abortion care more convenient while ensuring their privacy and allowing for meaningful client-provider interaction. These features of care should guide the development of strategies aimed at helping those in restricted settings, such as Mississippi, to overcome barriers to abortion care following the implementation of abortion bans in many states following the overturn of Roe v. Wade.

COVID-19 impact on facial trauma: Insights from Mississippi's only level 1 trauma center.

PURPOSE: Our primary aim was to understand and describe the impact of COVID-19 on the incidence and etiology of facial trauma in the state of Mississippi. METHODS: Retrospective review of facial trauma-related Emergency Department encounters in Mississippi from March 11, 2019 to March 10, 2021, divided into three time periods using the state of Mississippi's Governor's Office Executive Orders. Chi-square tests and segmented linear regressions were used for analysis. RESULTS: Patients presenting with facial trauma were typically male, 18-44 years old, and lived in urban zip codes. Insurance payors significantly differed across time periods. There were no significant differences in self-inflicted assault or accidental injury between the 3 time periods, with pre- and pandemic patients more likely to be self-pay while patients during recovery being more likely to have private insurance. During the pandemic, facial trauma from a family member, partner or spouse, or other person in the household significantly increased. CONCLUSION: Similar accidental facial trauma trends may reflect lower adherence to social distancing guidelines. The increase in facial trauma perpetrated by family members is consistent with reported increases in domestic violence during the pandemic. While overall facial trauma demographic patterns did not change significantly during the COVID-19 pandemic, there were notable changes in the etiology and insurance payor of facial trauma cases. LAY SUMMARY: The COVID-19 pandemic impacted healthcare systems worldwide, and our study seeks to understand how the pandemic affected incidence of facial trauma.

SARCOCYSTIS AND OTHER PARASITES IN FECES OF BOBCATS (LYNX RUFUS) FROM MISSISSIPPI.

Rectal contents of 56 adult bobcats (Lynx rufus) in 2014 and 2017 from remote areas of Mississippi were examined microscopically for parasite stages after the sugar flotation method. Among the helminths, eggs/larvae found were: Paragonimus sp. in 12, Toxocara cati-like in 16, trichurid-capillarid-like in 3, hookworms in 27, and lungworms in 28. Among the protozoa, oocysts/cysts found were: Cystoisospora felis-like in 2, Cystoisospora rivolta-like in 4, Cryptosporidium sp. in 1, and Giardia sp. in 1. Additionally, numerous Sarcocystis sporocysts were detected in the feces of 12 bobcats; sporocysts were described morphologically. The status of C. felis derived from the bobcat and other wild felids is reviewed and compared with C. felis from the domestic cat. It is the first record of C. rivolta from the bobcat. The presence of eggs of Paragonimus sp. and T. cati in feces of 21.4% and 28.5%, respectively, suggests a role for the bobcat in the dissemination of these zoonotic helminths in the environment in the wild. Taxonomy of coccidia of wild Felidae is discussed and Isospora lyncisLevine and Ivens, 1981 from the Lynx is now regarded as a species inquirenda.

Species-specific in situ hybridization confirms arrested development of Henneguya ictaluri in hybrid catfish (Channel Catfish × Blue Catfish) under experimental conditions, with notes on mixed-species infections in clinical cases of proliferative gill disease from Mississippi catfish aquaculture.

OBJECTIVE: Proliferative gill disease (PGD) in Channel Catfish Ictalurus punctatus and hybrid catfish (Channel Catfish × Blue Catfish I. furcatus) is attributed to the myxozoan Henneguya ictaluri. Despite evidence of decreased H. ictaluri transmission and impaired parasite development in hybrid catfish, PGD still occurs in hybrid production systems. Previous metagenomic assessments of clinical PGD cases revealed numerous myxozoans within affected gill tissues in addition to H. ictaluri. The objective of this study was to investigate the development and pathologic contributions of H. ictaluri and other myxozoans in naturally and experimentally induced PGD. METHODS: Henneguya species-specific in situ hybridization (ISH) assays were developed using RNAscope technology. Natural infections were sourced from diagnostic case submissions in 2019. Experimental challenges involved Channel Catfish and hybrid catfish exposed to pond water from an active PGD outbreak, and the fish were sampled at 1, 7, 10, 12, 14, 16, 18, and 20 weeks postchallenge. RESULT: Nine unique ISH probes were designed, targeting a diagnostic variable region of the 18S ribosomal RNA gene of select myxozoan taxa identified in clinical PGD cases. Partial validation from pure H. ictaluri, H. adiposa, H. postexilis, and H. exilis infections illustrated species-specific labeling and no cross-reactivity between different myxozoan species or the catfish hosts. After experimental challenge, mature plasmodia of H. ictaluri and H. postexilis formed in Channel Catfish but were not observed in hybrids, suggesting impaired or delayed sporogenesis in the hybridized host. These investigations also confirmed the presence of mixed infections in clinical PGD cases. CONCLUSION: Although H. ictaluri appears to be the primary cause of PGD, presporogonic stages of other myxozoans were also present, which may contribute to disease pathology and exacerbate respiratory compromise by further altering normal gill morphology. This work provides molecular confirmation and more resolute developmental timelines of H. ictaluri and H. postexilis in Channel Catfish and supports previous research indicating impaired or precluded H. ictaluri sporogony in hybrid catfish.

Toxic Tire Wear Compounds (6PPD-Q and 4-ADPA) Detected in Airborne Particulate Matter Along a Highway in Mississippi, USA.

Tire wear particles (TWPs) are a major category of microplastic pollution produced by friction between tires and road surfaces. This non-exhaust particulate matter (PM) containing leachable toxic compounds is transported through the air and with stormwater runoff, leading to environmental pollution and human health concerns. In the present study, we collected airborne PM at varying distances (5, 15 and 30 m) along US Highway 278 in Oxford, Mississippi, USA, for ten consecutive days using Sigma-2 passive samplers. Particles (~ 1-80 µm) were passively collected directly into small (60 mL) wide-mouth separatory funnels placed inside the samplers. Particles were subsequently subjected to solvent extraction, and extracts were analyzed for TWP compounds by high resolution orbitrap mass spectrometry. This pilot study was focused solely on qualitative analyses to determine whether TWP compounds were present in this fraction of airborne PM. The abundance of airborne TWPs increased with proximity to the road with deposition rates (TWPs cm-2 day-1) of 23, 47, and 63 at 30 m, 15 m, and 5 m from the highway, respectively. Two common TWP compounds (6PPD-Q and 4-ADPA) were detected in all samples, except the field blank, at levels above their limits of detection, estimated at 2.90 and 1.14 ng L-1, respectively. Overall, this work suggests airborne TWPs may be a potential inhalation hazard, particularly for individuals and wildlife who spend extended periods outdoors along busy roadways. Research on the bioavailability of TWP compounds from inhaled TWPs is needed to address exposure risk.

Characterization of a Putative New Member of the Genus Potyvirus from Kudzu (Pueraria montana var. lobata) in Mississippi.

Kudzu (Pueraria montana var. lobata), a plant native to Southeastern Asia, has become a major noxious weed covering millions of hectares in the Southern United States. A kudzu patch displaying virus-like symptoms located in Ackerman, northeastern Mississippi (MS), was used as a source for virus isolation and characterization involving mechanical and vector transmission, ultrastructural observation, surveys, Sanger and high-throughput genome sequencing, and sequence analyses. The results revealed the presence of a new potyvirus in infected kudzu, closely related to wisteria vein mosaic virus (WVMV) and provisionally named kudzu chlorotic ring blotch virus (KudCRBV). Genome features and pairwise comparison with six WVMV genomes currently available in GenBank and three additional isolates from MS sequenced in this work suggest that KudCRBV is likely a member of a new species in the genus Potyvirus. Furthermore, under experimental conditions, KudCRBV was successfully transmitted by cotton and potato aphids and mechanically to soybean and beans. A state-wide survey revealed several kudzu patches infected by the virus in northern MS.

Surveillance for Soil-Transmitted Helminths in High-Risk County, Mississippi, USA.

Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool specimens from 277 children in Rankin County, Mississippi. Kato-Katz microscopic smear, agar plate culture, and quantitative PCR indicated no soil-transmitted helminths. Nevertheless, further surveillance in other high-risk Mississippi counties is warranted.

Association of antecedent statin use on 30-day, 60-day and 90-day mortality among Mississippi Medicaid beneficiaries diagnosed with COVID-19.

OBJECTIVE: To assess if the antecedent statin use was associated with all-cause death among COVID-19 patients enrolled in Medicaid. DESIGN: Cohort study. SETTING: Mississippi Medicaid population. PARTICIPANTS: This study included 10 792 Mississippi Medicaid-enrolled patients between 18 and 64 years of age with a confirmed COVID-19 diagnosis from March 2020 to June 2021. INTERVENTION: Antecedent statin use, which was determined by a record of statin prescription in the 90-day period prior to the COVID diagnosis. MAIN OUTCOME MEASURES: The outcomes of interest included mortality from all cause within 30 days, 60 days and 90 days after index. RESULTS: A total of 10 792 patients with COVID-19 met the inclusion and exclusion criteria, with 13.1% of them being antecedent statin users. Statin users were matched 1:1 with non-users based on age, sex, race, comorbidities and medication use by propensity score matching. In total, the matched cohort consisted of 1107 beneficiaries in each group. Multivariable logistic regression showed that statin users were less likely to die within 30 days (adjusted OR: 0.51, 95% CI: 0.32 to 0.83), 60 days (OR: 0.56, 95% CI: 0.37 to 0.85) and 90 days (OR: 0.55, 95% CI: 0.37 to 0.82) after diagnosis of COVID-19. Those with low-intensity/moderate-intensity statin use had significantly lower mortality risk in the 60-day and the 90-day follow-up period, while the high intensity of statin use was only found to be significantly associated with a lower odd of mortality within 30 days post index. CONCLUSION: After COVID infection, Medicaid beneficiaries who had taken statins antecedently could be at lower risk for death. For patients with chronic conditions, continuity of care is crucial when interruptions occur in their medical care. Further research is required to further investigate the potential mechanisms and optimal use of statins in COVID-19 treatment.

Differing field methods and site conditions lead to varying bias in suspended sediment concentrations in the Lower Mississippi and Atchafalaya Rivers.

At sites that have been sampled for decades, changes in field and laboratory methods happen over time as instrumentation and protocols improve. Here, we compare the influence of depth- and point-integrated sampling on total, fine (< 0.0625 mm), and coarse (≥ 0.0625 mm) suspended sediment (SS) concentrations in the Lower Mississippi and Atchafalaya Rivers. Using historical field method information, we identified seven sites to test such differences. We found SS samples collected using point-integration tended to have higher concentrations than those collected using depth-integration. However, the presence and magnitude of the bias were inconsistent across sites. Bias was present at the site with less-than-ideal conditions (i.e., non-trapezoidal channel, non-uniform flow) and non-existent at the ideal site location, indicating the bias between sampling methods depends on site sampling conditions. When present, the bias is greater at higher concentrations and at moderate to high flows. At the less-than-ideal site, point-integrated samples can have 16% (total) and 34% (coarse) higher concentrations than depth-integrated samples. When flow effects are removed, this translates to a bias of 19, 9, and 8 mg per liter for total, fine, and coarse SS. When a change in field methods occurs, comparison samples and a rigorous evaluation of those samples are warranted to determine the proper course of action for a particular site. Often, the effect and solution will not be known until several years of comparison samples have been collected under a variety of hydrologic conditions.

Climate trends and maize production nexus in Mississippi: empirical evidence from ARDL modelling.

Climate change poses a significant threat to agriculture. However, climatic trends and their impact on Mississippi (MS) maize (Zea mays L.) are unknown. The objectives were to: (i) analyze trends in climatic variables (1970 to 2020) using Mann-Kendall and Sen slope method, (ii) quantify the impact of climate change on maize yield in short and long run using the auto-regressive distributive lag (ARDL) model, and (iii) categorize the critical months for maize-climate link using Pearson's correlation matrix. The climatic variables considered were maximum temperature (Tmax), minimum temperature (Tmin), diurnal temperature range (DTR), precipitation (PT), relative humidity (RH), and carbon emissions (CO2). The pre-analysis, post-analysis, and model robustness statistical tests were verified, and all conditions were met. A significant upward trend in Tmax (0.13 °C/decade), Tmin (0.27 °C/decade), and CO2 (5.1 units/decade), and a downward trend in DTR ( - 0.15 °C/decade) were noted. The PT and RH insignificantly increased by 4.32 mm and 0.11% per decade, respectively. The ARDL model explained 76.6% of the total variations in maize yield. Notably, the maize yield had a negative correlation with Tmax for June, and July, with PT in August, and with DTR for June, July, and August, whereas a positive correlation was noted with Tmin in June, July, and August. Overall, a unit change in Tmax reduced the maize yield by 7.39% and 26.33%, and a unit change in PT reduced it by 0.65% and 2.69% in the short and long run, respectively. However, a unit change in Tmin, and CO2 emissions increased maize yield by 20.68% and 0.63% in the long run with no short run effect. Overall, it is imperative to reassess the agronomic management strategies, developing and testing cultivars adaptable to the revealed climatic trend, with ability to withstand severe weather conditions in ensuring sustainable maize production.

Climate trends and soybean production since 1970 in Mississippi: Empirical evidence from ARDL model.

Studying historical response of crops to weather conditions at a finer scale is essential for devising agricultural strategies tailored to expected climate changes. However, determining the relationship between crop and climate in Mississippi (MS) remains elusive. Therefore, this research attempted to i) estimate climate trends between 1970 and 2020 in MS during the soybean growing season (SGS) using the Mann-Kendall and Sen slope method, ii) calculate the impact of climate change on soybean yield using an auto-regressive distributive lag (ARDL) econometric model, and iii) identify the most critical months from a crop-climate perspective by generating a correlation between the detrended yield and the monthly average for each climatic variable. Specific variables considered were maximum temperature (Tmax), minimum temperature (Tmin), diurnal temperature range (DTR), precipitation (PT), carbon dioxide emissions (CO2), and relative humidity (RH). All required diagnostic-tests i.e., pre-analysis, post-analysis, model-sensitivity, and assessing the models' goodness-of-fit were performed and statistical standards were met. A positive trend in Tmin (+0.25 °C/decade), and a negative trend in DTR (-0.18 °C/decade) was found. Although Tmax, PT, and RH showed non-significant trends, numerical changes were noted as +0.11 °C/decade, +3.03 mm/decade, and -0.06 %/decade, respectively. Furthermore, soybean yield was positively correlated with Tmin (in June and September), PT (in July and August), and RH (in July), but negatively correlated with Tmax (in July and August) and DTR (in June, July, and August). Soybean yield was observed to be significantly reduced by 18.11 % over the long-term and by 5.51 % over the short-term for every 1 °C increase in Tmax. With every unit increase in Tmin and CO2 emissions, the yield of soybeans increased significantly by 7.76 % and 3.04 %, respectively. Altogether, soybeans in MS exhibited variable sensitivity to short- and long-terms climatic changes. The results highlight the importance of testing climate-resilient agronomic practices and cultivars that encompass asymmetric sensitivities in response to climatic conditions of MS.