Meloidogyne arenaria (peanut root-knot nematode, PRKN) is an important pest in peanut (Arachis hypogea) production in the United States, including specialty Virginia-type peanuts. Cultivars resistant to PRKN and nematicide application are two available methods for managing PRKN. The objectives of this study were to determine the impacts of resistant Virginia-type peanut cultivars (Georgia-19HP and TifJumbo) on (1) management of PRKN abundances and damage and (2) total free-living nematode soil abundances. A common susceptible cultivar (Bailey II) with or without in-furrow fluopyram nematicide was compared to the resistant cultivars without nematicide in field trials in Florida (2022 and 2023). Resistant cultivars reduced midseason PRKN abundances from roots by 92-98% and final PRKN soil abundances by 81-93% relative to the untreated susceptible cultivar. Fluopyram reduced midseason PRKN root abundances by 65-74% and final PRKN soil abundances by 42-51% relative to untreated susceptible. Although PRKN reproduced on peanuts, no damage symptoms were observed, yield did not vary by treatment in 2022, and yield was significantly greater for fluopyram than either resistant cultivar in 2023. Impacts on total free-living nematode soil abundances were inconsistent. In summary, either fluopyram or resistant cultivars are effective tools for managing PRKN abundances in Virginia-type peanuts.

Root-knot nematodes (RKN; Meloidogyne spp.) are among the most damaging plant-parasitic nematodes. They parasitize almost every species of higher plant and induce the formation of galls along the plant roots, which are detrimental to plant growth. North Carolina's leading field crops are sweetpotato (Ipomoea batatas (L.) Lam.), soybean (Glycine max L. Merr), cotton (Gossypium hirsutum L.), and tobacco (Nicotiana tabacum L.), which are all hosts to several root-knot nematode species. This pathogen represents a major threat to farmers, obligating them to seek alternative crops that are non-host to root-knot nematodes that will help decrease soil populations and provide economic revenue. We tested seven sesame cultivars for their host status and potential resistance to four Meloidogyne species (M. arenaria, M. incognita, M. enterolobii, and M. hapla). We inoculated sesame seedlings with 1,000 nematode eggs of each species. Sixty days after inoculation, we harvested the plants to evaluate a visual gall severity rating, measure final egg counts, and calculate the reproductive factor (RF). All sesame cultivars had a significantly lower RF than the tomato (Solanum lycopersicum L.) cv. Rutgers control for all species of RKN except M. arenaria. The RF values for sesame cultivars inoculated with M. incognita and M. hapla were not significantly different from one another; however, there were significant differences in RF among sesame cultivars inoculated with M. enterolobii, suggesting that genetic variability of the host may play an important role in host status and conferring resistance.

Aiming to address the problems of poor separation of peanuts and soil and severe damage of pods during peanut harvesting in saline soil, a peanut digging and harvesting machine was designed using extrusion shaking vibration and roller extrusion. Theoretical calculations determined the structural parameters of critical components. The law of motion of the seedling soil assemblage at the stage of separation and transportation was derived by analyzing the kinematic properties. The soil extrusion vibration crushing dispersion and sieving process was analyzed, and the factors affecting soil crushing and separation were determined by establishing the extrusion collision model. One-way and orthogonal tests used soil content, breakage, and loss rates as test indicators. The orthogonal test showed that the working parameters were as follows: working speed was 0.889 m/s, the inclination angle was 21.5 degrees, the working line speed of the sieve surface was 2.00 m/s and the roller gap of the roller squeezing device was 37 mm, the peanut harvesting rate of soil content was 1.36%, the breakage rate was 0.78%, and the loss rate was 1.15%. The paper references developing a peanut harvester for clay-heavy soil with soil separation performance improvement.

Fall armyworm (FAW), Spodoptera frugiperda, has posed a serious threat to global food security since its discovery in Africa in 2016. Intercropping peanuts with maize is a very common cultivation practice, which can result in a high possibility of peanut damage by FAW. Our study investigated the feeding behavior, plant part preferences, and damage symptoms of FAW larvae on peanuts throughout the larval period, considering changes in population densities and the passage of time over the number of investigations. The results indicated that FAW larvae frequently inhabited peanut leaves, particularly the undersides of the leaves. Larvae moved from the leaves to the soil in the seedling pot to complete development. Furthermore, FAW larvae tended to feed on peanut leaves rather than stems regardless of population densities. Based on the damage symptoms, the feeding preferences of FAW larvae tended to be heart leaves, followed by mature leaves and stems. The most frequent damage symptoms caused by FAW to peanuts were window panes, followed by leafless. This study provides a reference for the integrated management of FAW in peanut fields.

Soil flooding, manifesting as submergence or waterlogging stress, significantly impacts plant species composition and agricultural productivity, particularly in regions with low rainfall. This study investigates the biochemical responses of two peanut (Arachis hypogaea L.) genotypes, DH-86 and GJG-32, under waterlogging stress. The experiment involved in-vivo pot trials where peanut plants were subjected to continuous waterlogging for 12 days at the flowering stage. Biochemical analyses of leaves conducted and revealed significant alterations in enzyme activities and metabolite concentrations. Key findings include variations in superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPOD), alpha-amylase, invertase, acid phosphomonoesterase activities, and changes in starch, proline, reducing sugars, and chlorophyll content. SOD, CAT, and GPOD activities exhibited differential responses between genotypes, highlighting DH-86's quicker recovery post-waterlogging. Notably, DH-86 demonstrated higher resilience, reflected in its rapid normalization of biochemical parameters, while GJG-32 showed prolonged stress effects. These findings underscore the importance of antioxidative enzyme systems in mitigating oxidative damage induced by waterlogging. This study enhances our understanding of the biochemical adaptations of peanut genotypes to waterlogging stress, offering valuable insights for breeding programs focused on improving flood tolerance in crops.

Vegetable oils contain traces of heavy metals that can cause irreversible damage to human health. The present study employed near-infrared spectroscopy and variable selection in conjunction with partial least squares (PLS) for the rapid determination of Cd content in peanut oil. Firstly, the spectral data of peanut oil test samples were preprocessed by different preprocessing methods, and the best preprocessing method was selected according to the results obtained by the PLS regression model. Then, PLS regression models were established to determine Cd content in peanut oil by variable iterative space shrinkage approach (VISSA), competitive adaptive reweighted sampling (CARS), multiple feature spaces ensemble strategy with least absolute shrinkage and selection operator (MFE-LASSO), and bootstrap soft shrinkage (BOSS), respectively. The results show that all four feature optimization algorithms could improve the prediction accuracy of the model. Among them, the CARS-PLS model had high prediction accuracy. Its prediction coefficient of determination (R2P) was 0.9666, the root mean square error of prediction (RMSEP) was 2.8207 mg/kg, and the relative prediction deviation (RPD) was 5.4705, respectively. In summary, near-infrared spectroscopy combined with chemometrics could be used for rapid quantitative detection of Cd in peanut oil.

Iron deficiency yellowing is a serious and widespread problem that seriously affects plant growth and development, ultimately damaging plant yield. Sulfur is one of the essential elements for plant growth and development, and plays an important role in crop stress resistance. Iron (Fe) and sulfur (S) play a core role in the mineral nutrients required for plant metabolism, as both elements are essential for the activity of several proteins involved in basic cellular processes. This research used peanuts as materials to explore the effect of exogenous sulfur on alleviating iron deficiency and yellowing in peanuts under iron deficiency and iron enrichment levels. A two-year field experiment was conducted on windblown sandy soil to determine peanut yield, photosynthetic rate, photosynthetic pigment content, and the activity of key enzymes such as protective enzymes in leaves and roots. The results showed that the application of exogenous sulfur can increase pod yield by an average of 12.6 %-21.6 %. The application of exogenous sulfur significantly increased the migration of iron from roots to the ground, and increased the accumulation of active iron in young leaves by 42.6-73.2 %. Exogenous sulfur application increased the content of GSH in leaves, reduced the damage of Fe-deficient to leaf tissue structure, and effectively increased or maintained the accumulation of photosynthetic compounds in leaves. In addition, exogenous sulfur application at Fe-sufficient levels promoted dry matter accumulation while increasing N and S nutrient content, thereby increasing the N: S ratio. Therefore, exogenous sulfur application significantly increased the content of Chl a and Chl b in leaves, as well as the net photosynthetic rate. The application of exogenous sulfur increased the activity of SOD, POD, and CAT enzymes in roots and leaves, decreased the content of H2O2 and MDA in leaves, and reduced the rate of O.2- generation, thereby enhancing the plant's resistance to oxidative stress. This confirms that the application of exogenous sulfur and sufficient iron is of great significance in reducing iron deficiency yellowing in peanuts and improving yield.

The study aims to evaluate the difference of nitrogen (N) utilization in peanut varieties with different nodulation efficiency and the contribution of different N sources to yield formation. Based on an outdoor pot experiment, N-15 isotope-labeled urea was used as a N source to investigate the effects of different N fertilization levels (N rates with 45, 75, 105, 135, 165 kg N ha(-1), defined as N45, N75, N105, N135 and N165 in the study, respectively) on peanut photosynthesis, photosynthate accumulation, yield, and N distribution and transport. The results showed that N application can improve peanut yield by creating photosynthesis, dry matter weight, and N accumulation, and the N105 treatment had the most significant effect. However, higher N applications inhibited the number of peanut root nodules. The ratio of N supply for peanuts from nodules, soil, and fertilizer at the pod setting stage was about 5:3:2, and the ratio of fertilizer distribution for low nodulation peanut variety of reproductive organ (pod) to nutrient organs (root, stem, leaf) was about 3:2, while the high nodulation variety was about 1:1. Biological N fixation is an important N source during peanut growth and development. Appropriate N fertilizer can further promote peanut growth and yield formation without inhibiting nodulation and N fixation. In agricultural production, optimizing N fertilizer management (105 similar to 135 kg N ha(-1)) in combination with using nodulation efficient peanut varieties not only promotes the N-cycling in agriculture, but also effectively reduce the waste of N fertilizer as well as environmental damage.

Peanut smut (Thecaphora frezzii) is one of the most important peanut diseases in Argentinian peanut production. This monocyclic soil-borne pathogen transforms kernels into spore masses. Spore liberation from broken infected pods during the harvest process is supposed to be the main mechanism of inoculum spread, with the subsequent spread among fields increasing the soil inoculum for future peanut cropping seasons. However, we are unaware of any published study on the role of wind (in terms of speed and direction) in how far smut spores spread. Therefore, we conducted an observational study where passive spore traps were distributed at harvest around six fields placed at 100, 200, 300, and 400 m away from each field's centroid in four cardinal directions. Three time slices were sampled: from the beginning of harvest to 90-, 180-, and 270-minutes continuously during harvest. Wind speed and direction were recorded at each trap. A generalized additive model was fitted to describe the spore spread. Modeling the dispersal shows that the spread is influenced by wind speed and the smut severely damaged pods incidence present at the harvested field. Additionally, spore size and proportion of different smut spore types were assessed (from a single unit spore to a 5-multinuclear propagule). No statistical differences were observed in the proportion of the spore types trapped. However, fewer spores were trapped at distances farther from the harvested area. This work led us to understand a fundamental component of the peanut smut cycle and epidemiology, which is to design management strategies. For example, avoiding harvest on windy days (typically >10 km h(-1)) to prevent the distant spread of inoculum for subsequent seasons or predicting the risk surrounding an infected field.

The toxicity of aluminum (Al) in acidic soil inhibits plant root development and reduces crop yields. In the plant response to Al toxicity, the initiation of programmed cell death (PCD) appears to be an important mechanism for the elimination of Al-damaged cells to ensure plant survival. In a previous study, the type I metacaspase AhMC1 was found to regulate the Al stress response and to be essential for Al-induced PCD. However, the mechanism by which AhMC1 is altered in the peanut response to Al stress remained unclear. Here, we show that a nuclear protein, mutator-like transposable element 9A (AhMULE9A), directly interacts with AhMC1 in vitro and in vivo. This interaction occurs in the nucleus in peanut and is weakened during Al stress. Furthermore, a conserved C2HC zinc finger domain of AhMULE9A (residues 735-751) was shown to be required for its interaction with AhMC1. Overexpression of AhMULE9A in Arabidopsis and peanut strongly inhibited root growth with a loss of root cell viability under Al treatment. Conversely, knock down of AhMULE9A in peanut significantly reduced Al uptake and Al inhibition of root growth, and alleviated the occurrence of typical hallmarks of Al-induced PCD. These findings provide novel insight into the regulation of Al-induced PCD. Mutator-like transposable element 9A interacts with metacaspase 1 and plays an important regulatory role in the peanut response to Al stress.