Search Results (18)

The fall armyworm, Spodoptera frugiperda, is a major migratory polyphagous insect pest of various crops. The essential nutrient and mineral profile of the host plants determines the feeding fitness of herbivorous insects. As a result, the growth and development of insects is affected. To determine the effect of the nutrient and mineral profile of different host plants (maize, castor bean, cotton, cabbage, okra, and sugarcane) on the growth and development of S. frugiperda, biological parameters like larval weight, pupal weight (male/female), and feeding and growth indices were calculated. The proximate compositions such as crude protein, crude fat, crude fibre, and ash and mineral contents of the tested host plants showed significant differences (p < 0.05). The feeding indices on these host plants also differed significantly (p < 0.05). The maximum relative growth rate (RGR), relative consumption rate (RCR), and consumption index (CI) were recorded in S. frugiperda larvae that fed on maize and castor bean leaves. The crude protein, dry matter, and ash contents in maize and castor bean were significantly higher and positively correlated with the RGR and RCR of S. frugiperda larvae. The larval, male and female pupal weights were the maximum in the larvae feeding on the castor bean host plant. These findings provide novel information based on nutritional ecology to develop sustainable integrated pest management strategies using selective crop rotation. Full article

Okra (Abelmoschus esculentus L.) is a highly nutritious vegetable rich in vitamins, minerals, and bioactive compounds, including polyphenols, offering numerous health benefits. Despite its nutritional value, okra remains underutilized in Europe; however, its cultivation and popularity may rise in the future with increasing awareness of its advantages. In agricultural practices, beneficial soil microorganisms, such as arbuscular mycorrhizal fungi (AMF), Trichoderma spp., Streptomyces spp., and Aureobasidium spp., play crucial roles in promoting plant health, enhancing agricultural productivity together with improved crop nutritional value. This study aimed to investigate the effects of individual and combined inoculation on the polyphenol content of okra fruits, as analyzed by HPLC. Moreover, growth parameters and glutathione-S-transferase enzyme (GST) activities of okra leaves were also estimated. Tested microorganisms significantly increased the yield of okra plants except for A. pullulans strain DSM 14950 applied individually. All microorganisms led to increased GST enzyme activity of leaves, suggesting a general response to biotic impacts, with individual inoculation showing higher enzyme activity globally compared to combined treatments. According to the polyphenol compound analysis, the application of tested microorganisms held various but generally positive effects on it. Only the combined treatment of F. mosseae and Streptomyces strain K61 significantly increased the coumaric acid content, and the application of Aureobasidium strain DSM 14950 had a positive influence on the levels of quercetin and quercetin-3-diglucoside. Our preliminary results show how distinct polyphenolic compound contents can be selectively altered via precise inoculation with different beneficial microorganisms. Full article

Uneven rainfall, in the context of global warming, can cause soil moisture fluctuations (SMFs) that harm crop growth, and it is not yet known whether nitrogen (N) can mitigate the harm caused by a strong SMF. This paper uses okra as a test subject and sets three SMFs of 45–55% FC (W₁), 35–65% FC (W₂), and 25–75% FC (W₃) and three N applications of 0 kg hm⁻² (N₀), 110 kg hm⁻² (N₁), and 330 kg hm⁻² (N₂) to investigate the effects of SMF and N application on the physiological and biochemical aspects of okra. The results demonstrated that okra exhibited the highest values in stem diameter, number of leaves, photosynthesis characteristics, antioxidant enzyme activity, and yield under the N₁ treatment. The average yield in the N₁ treatment was 149.8 g, significantly surpassing the average yields of the N₀ (129.8 g) and N₃ (84.0 g) treatments. Stomatal density, antioxidant enzyme activity, malondialdehyde content, and proline content in okra leaves were highest in the W₃ treatment, indicating that plants experienced stress in the W₃ treatment. However, the agronomic traits and yields of okra in the N₁ treatment were higher than those in the N₀ and N₁ treatments, indicating that the crop damage caused by W₃ could be mitigated by an appropriate amount of N application. The N₁W₁ treatment emerged as the most suitable combination for okra growth in this study, exhibiting the highest stem diameter, leaf count, photosynthetic characteristics, and yield (201.3 g). Notably, this yield was 67.8% higher than the lowest treatment (N2W3), signifying a significant improvement. Full article

Cyanobacteria, an important addition to biofertilizers, are gaining popularity for their multifaceted benefits in sustainable agriculture and ecosystem restoration. However, harmful algal blooms (HABs) in freshwater, predominantly caused by cyanobacteria, prevent sunlight penetration into the water and develop hypoxic and anoxic conditions. We collected cyanobacteria slurry from Lake Jesup (Central Florida, USA), repurposed it as a biofertilizer, and incorporated it in a typical South Florida calcite soil for high-value okra (Abelmoschus esculentus; var: Clemson spineless) production. Experiments were conducted at the Organic Garden Shade House and Greenhouse located inside the main campus of the Florida International University (FIU), FL, USA. A two-year experiment with four different treatments was conducted, namely, (a) control (C; no fertilizer applied), (b) total synthetic (TS), (c) total biofertilizer (TB; only cyanobacteria biofertilizer was applied), and (d) half and half (HH; 50% biofertilizer + 50% synthetic fertilizer), which were arranged in a randomized complete block design (RCBD) with six replications for each treatment. Our results indicate that TB and TS produced about 29 to 33% higher SPAD (soil plant analytical development) readings than the control. The absence of interveinal chlorosis (yellowing of leaves) in the TB and HH treatments suggests that the cyanobacteria-based biofertilizer had a role in supplying one of the critical micronutrients, iron (Fe). Analysis of the biofertilizer indicated 2000 ppm Fe content, which directly supports our observation. Similarly, average plant height (61 cm), yield (130 gm per pot), and crop biomass (67 gm) productions were significantly higher in TB than in the control. Overall, this study documents the potential of cyanobacteria biofertilizers as a viable option compared to synthetic fertilizers for sustainable crop production and soil health improvement. Full article

Several plants rich in phenolic compounds have many uses in the food and pharmaceutical fields. However, after extraction, these active biomolecules are susceptible to degradation. Microencapsulation is a possible solution to prevent this rapid degradation. In this study, phenolic compounds from the okra Abelmoschus esculentus L’s leaves, fruits and seeds were extracted using microwave-assisted extraction and then microencapsulated via the spray drying technique using maltodextrin combined with pectin (in a ratio of 10:1) as an encapsulation material. The total phenolic content, DPPH scavenging and antimicrobial activities of okra extracts and encapsulated samples were evaluated to verify the encapsulation efficiency. Particle size distribution determination and scanning electron microscopy of the microcapsules were also carried-out. The ethanolic leaf extract showed higher significant levels of total phenolic compounds (162.46 ± 4.48 mg GAE/g DW), and anti-oxidant (75.65%) and antibacterial activities compared to those of other aqueous and ethanolic extracts from fruits and seeds. Furthermore, the spray-dried ethanolic leaf extract had the highest total phenolic content. However, the encapsulated ethanolic fruit extract had the highest percentage of DPPH scavenging activity (30.36% ± 1.49). In addition, antibacterial activity measurements showed that the addition of ethanolic and aqueous seed microcapsules provided a significant zone of inhibition against the bacterium Brochotrix thermosphacta (38 mm and 30 mm, respectively). Okra aqueous leaf microcapsules showed the smallest Sauter mean diameter values (7.98 ± 0.12 µm). These data are applicable for expanding the use of okra leaves, fruits and seeds as food additives and/or preservatives in the food industry. Full article

Genome sequencing is important for discovering critical genes in crops and improving crop breeding efficiency. Generally, fresh, young leaves are used for DNA extraction from plants. However, seeds, the storage form, are more efficient because they do not require cultivation and can be ground at room temperature. Yet, only a few DNA extraction kits or methods suitable for seeds have been developed to date. In this study, we introduced an improved (IMP) Boom method that is relatively low-cost, simple to operate, and yields high-quality DNA that can withstand long-read sequencing. The method successfully extracted approximately 8 µg of DNA per gram of seed weight from soybean seeds at an average concentration of 48.3 ng/µL, approximately 40-fold higher than that extracted from seeds using a common extraction method kit. The A_260/280 and A_260/230 values of the DNA were 1.90 and 2.43, respectively, which exceeded the respective quality thresholds of 1.8 and 2.0. The DNA also had a DNA integrity number value (indicating the degree of DNA degradation) of 8.1, higher than that obtained using the kit and cetyltrimethylammonium bromide methods. Furthermore, the DNA showed a read length N₅₀ of 20.96 kbp and a maximum read length of 127.8 kbp upon long-read sequencing using the Oxford Nanopore sequencer, with both values being higher than those obtained using the other methods. DNA extracted from seeds using the IMP Boom method showed an increase in the percentage of the nuclear genome with a decrease in the relative ratio of chloroplast DNA. These results suggested that the proposed IMP Boom method can extract high-quality and high-concentration DNA that can be used for long-read sequencing, which cannot be achieved from plant seeds using other conventional DNA extraction methods. The IMP Boom method could also be adapted to crop seeds other than soybeans, such as pea, okra, maize, and sunflower. This improved method is expected to improve the efficiency of various crop-breeding operations, including seed variety determination, testing of genetically modified seeds, and marker-assisted selection. Full article

To study the host range of Rose rosette virus (RRV), we employed crude sap inoculum extracted from RRV-infected roses and the RRV infectious clone. We inoculated plants from the families Solanaceae, Cucurbitaceae, Leguminosae, Malvaceae, Amaranthaceae, and Brassicaceae. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect RRV in the inoculated plants throughout their growth stages. Interestingly, RRV was detected in the newly developed leaves of tomato, pepper, tobacco, cucumber, squash, zucchini, pumpkin, pea, peanut, soybean, spinach, okra, and Chenopodium spp. The speed of upward advancement of RRV within infected plants was variable between plants as it took two to three weeks for some plant species and up to five weeks in other plant species to emerge in the newest leaves. No severe symptoms were detected on most of the inoculated plants. Chenopodium spp., spinach, cucumber and Nicotiana rustica exhibited either chlorotic or necrotic lesions with variable shapes and patterns on the systemically infected leaves. Double membrane-bound particles of 80–120 nm in diameter were detected by transmission electron microscopy in the infected tissues of cucumber, pepper, and N. benthamiana plants. This finding infers the validity of mechanical inoculation for RRV on a wide range of plants that would serve as potential natural reservoirs. Full article

In this work, stable and spherical silver nanoparticles (AgNPs) were synthesized in situ from silver salt (silver nitrate) using the aqueous extract of the okra plant (Abelmoschus esculentus) at room temperature and ambient pH conditions. The influences of different parts of the plant (such as the leaves, stems, and pods) on the chemical-reducing effectiveness of silver nitrate to silver nanoparticles were investigated. The aqueous extract of the leaves was found to be more effective in the chemical reduction of silver nanoparticles and in stabilizing them at the same time. The silver nanoparticles produced were stable and did not precipitate even after storage for 1 month. The extract of the stem was less effective in the reduction capacity followed by the extract of the pods. The results indicate that the different amounts of phytochemicals present in the leaves, stems, and pods of the okra plant are responsible for the chemical reduction and stabilizing effect. The silver nanoparticles were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The surface plasmon resonance (SPR) peak at 460 nm confirmed the formation of silver nanoparticles. The nanoparticles were spherical with an average size of 16 nm and polycrystalline with face-centered cubic (fcc) structures. The z-scan technique was used to study the nonlinear refraction and absorption coefficients of AgNPs at wavelengths of 488 and 514 nm under C.W. mode excitation. The nonlinear refraction index and nonlinear absorption coefficients were calculated in the theoretical equations in the experimental data. The antibacterial properties of the nanoparticles were evaluated against Gram-positive and Gram-negative bacteria. Full article

Epigenetic changes such as DNA methylation and histone modifications, when meiotically inherited across generations, can act as a stable evolutionary force that is independent of any accompanying DNA mutations. Certain histone deacetylase (HDAC)-inhibiting chemicals such as Trichostatin A (TSA) and sodium butyrate are known to regulate the total acetylated histones in the genome, which is important for regulating the expression of various traits in all organisms. This study investigated all morphological variations in traits of Abelmoschus esculentus L. (okra) induced by different doses of Trichostatin A in a popular okra variety, Arka Abhay. Two sets of seeds were treated with two doses (0.4 µM and 1.2 µM) of TSA and were incubated in the chemical for three and five days, respectively, to record the effects of dose and incubation periods on various agronomic characters of okra. The treatment of TSA had a negative impact on the majority of the characters under evaluation. Total seedlings emerged, and mean shoot and root length were retarded following the TSA treatment. Extremely dwarfed plants with malformed leaves and flowers were a common observation. Pollen sterility combined with distortion of the reproductive whorls of the flowers were particularly pronounced at high doses with a prolonged incubation period. Treated plants had a significantly delayed first flowering and produced short fruits with altered morphology. Variations in seeds with respect to the number, colour and size were also recorded. Total reduction with respect to seedling parameters, total pollen production, the number of fertile pollens, plant height and other damaging effects on leaves, flowers, fruits and seeds increased as the dose and incubation period increased. Statistical analysis revealed the significant negative effect of TSA treatments on plant height, the number of ridges and locules per fruit, number of seeds per fruit and test weight. The treatment, 1.2 µM Trichostatin A incubated for three days, showed a remarkable difference as traits such as total field emergence, seedling parameters and days to first flowering plant height, number of seeds per fruit and test weight deviated from the expected trend of decreasing growth parameters as the dose and incubation period increased. The study further revealed that the treatment (1.2 µM TSA incubated for three days) can be suggested for use in okra to induce epigenetic variations without significantly compromising the growth and vigour parameters of okra. Full article

Determining the physicochemical properties of anthill and termite mound soils and their combinations with ordinary top soil and the assessment of their effects on the germination, growth and yield performance of eggplant and okra under screenhouse conditions, were the goals of this study. The six soil treatments used are as follows: (I) pure anthill soil (AHS), (II) pure termite mound soil (TMS), (III) top soil (control) (TS), (IV) anthill +top soil (AHS + TS), (V) termite mound +top soil (TMS + TS), and (VI) anthill + termite mound soils (AHS + TMS). The physicochemical properties of these treatments were analyzed. A standard seed-germination experiment arranged in a completely randomized block design (30 seeds per treatment per tested crop) was carried out in a screenhouse. For the growth experiment, a pot experiment arranged on top of tables using a completely randomized design (CRD) was carried out in the screenhouse and the growth and yield were determined at seven (eggplant) and eight (okra) weeks. The results show that all treatments are acidic with pH, ranging from 3.3 to 4.5. The treatment containing anthill and anthill soils had higher EC (µS/CM), organic carbon (%), nitrogen (%), and phosphorus (%) compared to the control (top soil). Treatment had a significant (p < 0.05) effect on the germination indices of eggplant and okra. Enhanced seed germination was obtained with eggplant and okra seeds sown in ordinary top soil amended with anthill soil compared to the control. The growth and yield of eggplant and okra were significantly (p < 0.05) affected by treatment. Generally, eggplant and okra grown using anthill soils (alone or mixed) had taller plants, bigger stem girth and leaf area, and a higher number of leaves per plant compared to those grown on top soil. Eggplant and okra grown on anthill and termite mound soils and their combinations with ordinary top soils had heavier fresh whole plant and root biomass compared to the control. It can be concluded that these results indicate that anthill and termite mound soils can serve as cheap alternative sources of nutrients for the cultivation of common vegetables by smallholder farmers in southern Sierra Leone. Full article

Palm bunch ash (PBA), a waste biomass from the palm oil industry, has been widely regarded as an alternative source of fertilizer to improve soil health, plant growth, and yield. Glutathione (GSH), a bioactive tripeptide with potent antioxidant properties, has been proposed as a plant growth regulator that improves stress tolerance in plants. However, the use of PBA in combination with GSH has yet to be explored and remains a gap in the literature. Herein, we aimed to assess the individual and the combinatory effects of PBA and GSH on vegetative plant growth, whereby okra was selected as the model plant and cultivated under well-watered, outdoor conditions. Plant growth parameters such as plant height, stem girth, number of leaves, and leaf surface area were measured over a period of two months. The results showed that the application of PBA and GSH significantly influenced the plant growth parameters. The GSH-treated group recorded the tallest plant height (47.19 cm) as compared to the control group, PBA-treated group, and combination group of PBA and GSH. The combination group of PBA and GSH recorded the best parameters in terms of stem girth (4.45 mm), number of leaves (6.35), leaf surface area (118.38 cm²) with improved resistance towards diseases. These results implied that the combined application of PBA and GSH may have led to a synergistic effect on okra plant growth. Our findings suggest that the combined application of PBA and GSH is indeed recommended to improve plant growth and development. Full article

The improvement of crop yield and quality are currently of prime concern to achieve global food security and sustainability. Plant elicitation with salicylic acid (SA) has been shown to play a key role in regulating plant growth and productivity. Here, the effects of foliar SA application (1, 2, and 4 mM) on antioxidant capacity and phenolic metabolism, among other biochemical parameters, were studied in okra leaves. The results showed that SA treatments markedly increase the levels of endogenous free SA and trigger the accumulation of chlorophylls, soluble proteins, proline, antioxidant capacity, and phenolic compounds, alongside the stimulation of the enzymatic activities of phenylalanine ammonia-lyase and peroxidase, with these changes being paralleled by decreased levels of lipid peroxidation. The beneficial effects of SA treatments were also tested on field-grown okra plants. Results revealed that yield-associated agronomic attributes significantly increased upon SA treatments, especially at 2 mM SA. Altogether, these results point to a connection between SA-induced antioxidant system strengthening and crop growth and productivity. Therefore, foliar application of SA seems to be a potent and workable approach to enhance okra crop quality and yield. Full article

The aim of this study was to investigate the feasibility of using sewage sludge (SS) biosolids as a low-cost soil fertilizer to improve soil characteristics and crop yields. Okra (Abelmoschus esculentus (L.) Moench) plants were grown in soil supplemented with different concentrations of SS (0, 10, 20, 30, 40, and 50 g/kg). The results showed that SS soil application led to improved soil quality with a 93% increase of organic matter (at SS dose of 10 g/kg), decreased pH (a reduction from 8.38 to 7.34), and enhanced macro- and micro- nutrient contents. The levels of all the investigated heavy metals (HMs; Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the postharvest SS-amended soil were within the prescribed safe limits. The application of SS to soil considerably enhanced the growth parameters of okra plants. Total biomass increased 13-fold and absolute growth rate increased 10-fold compared to plants grown in nonamended (control) soils. Among the applied SS doses, the 10 g/kg SS dose led to the highest values of the measured growth parameters, compared to those of plants grown in control soils. The induced growth at 10 g/kg SS was accompanied by a substantial increase in metal content in roots, stems, leaves, and fruits; however, all levels remained within safe limits. Consequently, the data presented in this study suggest that SS could be used as a sustainable organic fertilizer, also serving as an ecofriendly method of SS recycling. Full article

Prediction models were developed to estimate the extent to which the metals Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were taken up by the fruits, the leaves, the stems, and the roots of the okra plant, Abelmoschus esculentus (L.) Moench., grown under greenhouse conditions in soil modified with a spectrum of sewage sludge concentrations: 0, 10, 20, 30, 40, and 50 g/kg. All the metals under investigation, apart from Cd, were more concentrated in the A. esculentus roots than in any other organ. Overall, the sum of the metal concentration (mg/kg) within the varying plant tissues can be ranked in the following order: roots (13,795.5) > leaves (1252.7) > fruits (489.3) > stems (469.6). For five of the metals (i.e., Cd, Co, Fe, Mn, and Pb), the BCF was <1; for the remaining four metals, the BCF was >1, (i.e., Cr, 1.074; Cu, 1.347; Ni, 1.576; and Zn, 1.031). The metal BCFs were negatively correlated with the pH of the soil and positively correlated with soil OM content. The above-ground tissues exhibited a TF < 1 for all metals, apart from Cd with respect to the leaves (2.003) and the fruits (2.489), and with the exception of Mn in relation to the leaves (1.149). Further positive associations were demonstrated for the concentrations of all the metals in each examined plant tissue and the corresponding soil metal concentration. The tissue uptakes of the nine metals were negatively correlated with soil pH, but positively associated with the OM content in the soil. The generated models showed high performance accuracy; students’ t-tests indicated that any differences between the measured and forecasted concentrations of the nine metals within the four tissue types of A. esculentus failed to reach significance. It can, therefore, be surmised that the prediction models described in the current research form a feasible method with which to determine the safety and risk to human health when cultivating the tested species in soils modified with sewage sludge. Full article

Plant endophytic bacteria live inside host plants, can be isolated from surface-sterilized plant tissues, and are non-pathogenic. These bacteria can assist host plants in obtaining more nutrients and can improve plant growth via multiple mechanisms. Certain Gram-negative Burkholderia species, including rhizobacteria, bioremediators, and biocontrol strains, have been recognized for their plant-growth-promoting abilities, while other isolates have been identified as opportunistic plant or human pathogens. In this study, we observed the auxin production, siderophore synthesis, and phosphate solubilization abilities of B. seminalis strain 869T2. Our results demonstrated that strain 869T2 promoted growth in Arabidopsis, ching chiang pak choi, pak choi, loose-leaf lettuce, romaine lettuce, red leaf lettuce, and Chinese amaranth. Leafy vegetables inoculated with strain 869T2 were larger, heavier, and had more and larger leaves and longer and heavier roots than mock-inoculated plants. Furthermore, inoculations of strain 869T2 into hot pepper caused increased flower and fruit production, and a higher percentage of fruits turned red. Inoculation of strain 869T2 into okra plants resulted in earlier flowering and increased fruit weight. In conclusion, the plant endophytic bacterium Burkholderia seminalis 869T2 exerted positive effects on growth and production in several plant species. Full article