Search Results (23)

This innovative method improves the inefficient optimization of the parameters of a pneumatic drum seed metering device. The method applies a backpropagation neural network (BPNN) to establish a predictive model and multi-objective particle swarm optimization (MOPSO) to search for the optimal solution. Six types of small vegetable seeds were selected to conduct orthogonal experiments of seeding performance. The results were used to build a dataset for building a BPNN predictive model according to the inputs of the physical properties of the seed (thousand-grain weight, kernel density, sphericity, and geometric mean diameter) and the parameters of the device (vacuum pressure, drum rotational speed, and suction hole diameter). From this, the model output the seeding performance indices (the missing and reseeding indexes). The MOPSO algorithm uses the BPNN predictive model as a fitness function to search for the optimal solution for three types of seeds, and the optimized results were verified through bench experiments. The results show that the predicted qualified indices for tomato, pepper, and bok choi seeds are 85.50%, 85.52%, and 84.87%, respectively. All the absolute errors between the predicted and experimental results are less than 3%, indicating that the results are reliable and meet the requirements for efficient parameter optimization of a seed metering device. Full article

In the context of pollution-free waste treatment, anaerobic fermentation liquid (AFL), a prominent by-product of biogas engineering, has emerged as a focal point in contemporary research. Concurrently, vitamin C, an active compound abundant in fruits and vegetables, possesses extensive application potential. The development of efficient extraction processes and the utilization of its biological activities have garnered significant attention from researchers. This study investigated the impact of AFL on the growth and vitamin C content of Bok choy through field trials of varying concentrations of AFL. The results indicated that the growth characteristics of Bok choy exhibited a concentration-dependent trend with increasing AFL dosage, with the highest yield observed in the AFL-2 group (8.43 kg/m²). Additionally, with the increase in the concentration of the AFL application, the vitamin C content in Bok choy exhibited a trend of initially increasing and then decreasing, reaching its highest value (70.83 mg/100 g) in the AFL-1 group. Furthermore, response surface methodology was employed to optimize the microwave-assisted organic solvent extraction process of vitamin C, revealing that the optimal conditions for microwave-assisted extraction using a 2% citric acid solution were as follows: a microwave power of 313 W, a microwave time of 1.3 min, and a liquid-to-solid ratio of 16.4:1 v/w, achieving a vitamin C extraction rate of 90.77%. Subsequent mechanistic studies on colitis repair demonstrated that the combination of vitamin C and allicin significantly enhanced the ability of intestinal microorganisms to ferment and degrade complex carbohydrates in colitis-afflicted mice, thereby alleviating intestinal inflammation, markedly reducing bacterial invasion signals on intestinal epithelial cells, and decreasing the risk of intestinal infection. This study provides a valuable perspective for the harmless utilization of agricultural waste, and provides a theoretical basis and technical support for the high-value utilization of natural active ingredients. Full article

The objective of this study was to compare the effects of biochar extract (BE) and mineral potassium fulvic acid (MPFA) on the salt tolerance and growth of Bok Choy (Shanghai Bok Choy) under saline conditions, aiming to utilize saline groundwater resources in the Yellow River Delta region. Based on the mineralization level of saline groundwater in the Yellow River Delta region, all the treatments were cultured in a nutrient solution containing 6 g·L⁻¹ NaCl. Nine treatments were set up: BE (C1: 1 g, C2: 5 g, C3: 10 g, C4: 15 g·L⁻¹), MPFA (H1: 0.2 g, H2: 0.4 g, H3: 0.6 g, H4: 0.8 g·L⁻¹), and a control (CK). The results showed that both the BE and MPFA reduced MDA accumulation, increased SOD and CAT enzyme activities, thereby increasing the number of effective leaves, the maximum leaf length, and the maximum leaf width of Shanghai Bok Choy. However, MPFA was better than the BE at increasing the antioxidant enzyme activities and total chlorophyll content. Correlation analysis revealed that the hydrogen peroxide content and CAT enzyme activity were the most important factors affecting Shanghai Bok Choy yield. Compared to the CK, the BE treatments reduced the hydrogen peroxide content by 1.1–46.4% and increased the CAT enzyme activity by 4.1–68.0%, while the MPFA treatments increased the hydrogen peroxide content and decreased the CAT enzyme activity. Consequently, the fresh weight of Shanghai Bok Choy treated with the BE was 11.01–112.21% higher than the MPFA treatments and 5.17–49.70% higher than the CK. Overall, C3 had significantly lower hydrogen peroxide content than the CK and the highest CAT enzyme activity, which was markedly better than the MPFA treatments. This suggests that C3 may be an effective method for improving the salt tolerance and growth of Shanghai Bok Choy under salt stress. This study provides favorable data to support the solution to the problem of agricultural water use and the realization of sustainable development in the Yellow River Delta. Full article

Chicken feathers represent a viable material for producing biochar adsorbents. Traditional slow pyrolysis methods often result in sulfur element losses from chicken feathers, whereas hydrothermal reactions generate substantial amounts of nutrient-rich hydrothermal liquor. Magnesium-modified high-sulfur hydrochar MWF was synthesized through magnesium modification, achieving a S content of 3.68%. The maximum equilibrium adsorption amounts of MWF for Cd²⁺ and Pb²⁺ were 25.12 mg·g⁻¹ and 70.41 mg·g⁻¹, respectively, representing 4.00 times and 2.75 times of WF. Magnesium modification elevated the sulfur content, pH, ash content, and electronegativity of MWF. The primary mechanisms behind MWF’s adsorption of Cd²⁺ and Pb²⁺ involve magnesium ion exchange and complexation with C=O/O=C–O, quaternary N, and S functional groups. MWF maintains robust stability and antioxidative properties, even with low aromaticity levels. Given the lower energy consumption during hydrochar production, MWF offers notable carbon sequestration benefits. The hydrothermal solution derived from MWF is nutrient-rich. Following supplementation with inorganic fertilizer, the hydrothermal solution of MWF significantly enhanced bok choy growth compared to the control group. In general, adopting magnesium-modified hydrothermal reactions to produce hydrochar and converting the resultant hydrothermal solution into water-soluble fertilizer proves a viable strategy for the eco-friendly utilization of chicken feathers. This approach carries substantial value for heavy metal remediation and agricultural practices. Full article

High temperatures have adverse effects on the yield and quality of vegetables. Bok choy, a popular vegetable, shows varying resistance to heat. However, the mechanism underlying the thermotolerance of bok choy remains unclear. In this study, 26 bok choy varieties were identified in screening as being heat-resistant at the seedling stage; at 43 °C, it was possible to observe obvious heat damage in different bok choy varieties. The physiological and biochemical reactions of a heat-tolerant cultivar, Jinmei (J7), and a heat-sensitive cultivar, Sanyueman (S16), were analyzed in terms of the growth index, peroxide, and photosynthetic parameters. The results show that Jinmei has lower relative conductivity, lower peroxide content, and higher total antioxidant capacity after heat stress. We performed transcriptome analysis of the two bok choy varieties under heat stress and normal temperatures. Under heat stress, some key genes involved in sulfur metabolism, glutathione metabolism, and the ribosome pathway were found to be significantly upregulated in the heat-tolerant cultivar. The key genes of each pathway were screened according to their fold-change values. In terms of sulfur metabolism, genes related to protease activity were significantly upregulated. Glutathione synthetase (GSH2) in the glutathione metabolism pathway and the L3e, L23, and S19 genes in the ribosomal pathway were significantly upregulated in heat-stressed cultivars. These results suggest that the total antioxidant capacity and heat injury repair capacity are higher in Jinmei than in the heat-sensitive variety, which might be related to the specific upregulation of genes in certain metabolic pathways after heat stress. Full article

This study was aimed at problems associated with low fertilizer using efficiency, excessive nitrate content of vegetables, and soil degradation in greenhouse vegetable production. A pot experiment was conducted to assess the effects of applying biochar-coated nitrogen fertilizer (BCNF) on the yield, quality, and nitrate content of bok choy (Brassica rapa subsp. Chinensis) as well as on soil nutrients in greenhouses. Four treatments were set up as follows: no nitrogen fertilizer application (BA), chemical nitrogen fertilizer application (CK), biochar-coated nitrogen fertilizer application (BCNF, the amount of nitrogen was equal to that of chemical fertilizer), and reduced biochar-coated nitrogen fertilizer application (D-BCNF, the amount of fertilizer was 80% of BCNF). Compared with the other treatments, BCNF treatment increased chlorophyll content, plant height, maximum leaf length, maximum leaf width, and other biological characters of bok choy. Compared with CK treatment, BCNF treatment increased the fresh weight of bok choy by 14.02%, while reducing the root–shoot ratio and nitrate content by 19.1% and 46%, respectively. It was further found that the application of BCNF could effectively increase the content of soil organic matter; reduce the leaching loss of nitrate nitrogen, exchangeable calcium and magnesium; and effectively improve nitrogen use efficiency. Therefore, the application of BCNF can not only reduce the loss of fertilizer nutrients, promote plant growth, and improve fertilizer utilization, but it can also improve soil nutrients, fix carbon, and reduce emissions. It is a new type of environmental protection fertilizer with application prospects. Full article

Spodoptera frugiperda is Indonesia’s relatively new invasive polyphagous insect pest. So far, S. frugiperda infestation has only been reported in corn and rice in Indonesia. However, S. frugiperda is known to feed on many commercial crops in other countries. To date, information on the biological parameters of S. frugiperda is limited in Indonesian ecologies. Since host plants are a critical factor for insect life history and have the potential to be used for pest control strategies, it is essential to study the biology and survival of S. frugiperda on different host plants. This research aimed to investigate the survival, development time, and fecundity of S. frugiperda on other host plant species to predict possible infestation rates for use in pest management. The study was conducted by rearing S. frugiperda on 14 common cultivated host plant species in Indonesia. The survival rate, development time, fecundity, and potential attack rate of S. frugiperda on various tested host plants were analyzed in this study. The findings revealed that corn was the primary host for S. frugiperda. The ability of S. frugiperda to survive on papaya, water spinach, banana, spinach, cucumber, and coco grass indicates that these plants are potential alternate hosts for S. frugiperda. Long beans, bok choy, choy sum, and beans might be indicated as a shelter for S. frugiperda. Meanwhile, inappropriate hosts for S. frugiperda include cabbage, broccoli, and cauliflower due to their low survival rate on these plants. This research indicates that these plants have the potential to be used as a hedge, trap, or bunker plant in S. frugiperda management strategies. However, to prevent detrimental damage, control methods are needed in an integrated manner, including monitoring pest populations, habitat manipulation, and conservation of natural enemies. Full article

The contamination of agricultural products, such as vegetables, by pesticide residues has received considerable attention worldwide. Pesticide residue on vegetables constitutes a potential risk to human health. In this study, we combined near infrared (NIR) spectroscopy with machine learning algorithms, including partial least-squares discrimination analysis (PLS-DA), support vector machine (SVM), artificial neural network (ANN), and principal component artificial neural network (PC-ANN), to identify pesticide residue (chlorpyrifos) on bok choi. The experimental set comprised 120 bok choi samples obtained from two small greenhouses that were cultivated separately. We performed pesticide and pesticide-free treatments with 60 samples in each group. The vegetables for pesticide treatment were fortified with 2 mL/L of chlorpyrifos 40% EC residue. We connected a commercial portable NIR spectrometer with a wavelength range of 908–1676 nm to a small single-board computer. We analyzed the pesticide residue on bok choi using UV spectrophotometry. The most accurate model correctly classified 100% of the samples used in the calibration set in terms of the content of chlorpyrifos residue on samples using SVM and PC-ANN with raw data spectra. Thus, we tested the model using an unknown dataset of 40 samples to verify the robustness of the model, which produced a satisfactory F1-score (100%). We concluded that the proposed portable NIR spectrometer coupled with machine learning approaches (PLS-DA, SVM, and PC-ANN) is appropriate for the detection of chlorpyrifos residue on bok choi. Full article

In this study, nanostructured gold was successfully prepared on a bare Au electrode using the electrochemical deposition method. Nanostructured gold provided more exposed active sites to facilitate the ion and electron transfer during the electrocatalytic reaction of organophosphorus pesticide (methyl parathion). The morphological and structural characterization of nanostructured gold was conducted using field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), which was further carried out to evaluate the electrocatalytic activity towards methyl parathion sensing. The electrochemical performance of nanostructured gold was investigated by electrochemical measurements (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)). The proposed nanostructured gold-modified electrode exhibited prominent electrochemical methyl parathion sensing performance (including two linear concentration ranges from 0.01 to 0.5 ppm (R² = 0.993) and from 0.5 to 4 ppm (R² = 0.996), limit of detection of 5.9 ppb, excellent selectivity and stability), and excellent capability in determination of pesticide residue in real fruit and vegetable samples (bok choy and strawberry). The study demonstrated that the presented approach to fabricate a nanostructured gold-modified electrode could be practically applied to detect pesticide residue in agricultural products via integrating the electrochemical and gas chromatography coupled with mass spectrometry (GC/MS-MS) analysis. Full article

Integrating urban agriculture with aquaculture can reduce the use and cost of water, competition for water, chemical fertilizers, and environmental impact of discharging nutrient-rich agricultural water into fresh and saltwater bodies. In addition, aquaculture in cities can directly benefit human health by providing a local source of lean protein. Despite the potential advantages, few studies have demonstrated the feasibility and production advantages of using aquaculture wastewater to fertigate specialty crops in an urban environment. Therefore, we grew four spring crops (bok choy, tatsoi, radish, turnip) and two fall crops (pole beans, sugar snap peas) in nutrient-rich effluent from fish aquaculture versus well or municipal water to evaluate whether the effluent improved soil fertility and crop production. The fish effluent resulted in changes to the soil through an increase in pH and potassium and to crop production through a 9.1% increase in the number of pole beans (mass of beans also trended toward significance). The soils we used were relatively nutrient-rich prior to the application of the fish effluent, which may be responsible for the limited impact, and differences may be more apparent in acidic and nutrient-poor soils or when fertigation is used over a longer duration. Full article

Release of nanoceria (nCeO₂) into the environment has caused much concern about its potential toxicity, which still remains poorly understood for soil microorganisms. In this study, nanoceria and cerium (III) nitrate at different doses (10, 100 and 500 mg/kg) were applied to bok choy (Brassica rapa subsp. chinensis), grown in potting soil, to investigate the responses of soil bacterial communities to nanoceria (NC) and ionic cerium (IC) applications. The results showed that bacterial richness was slightly increased in all cerium treatments relative to the negative control without cerium amendment (CK), but a significant increase was only found in IC500. The patterns of bacterial community composition, predicted functions and phenotypes of all NC treatments were significantly differentiated from IC and CK treatments, which was correlated with the contents of cerium, available potassium and phosphorus in soil. The co-occurrence network of bacterial taxa was more complex after exposure to ionic cerium than to nanoceria. The keystone taxa of the two networks were entirely different. Predicted functions analysis found that anaerobic and Gram-negative bacteria were enriched under nanoceria exposure. Our study implies that Proteobacteria and nitrifying bacteria were significantly enriched after exposure to nanoceria and could be potential biomarkers of soil environmental perturbation from nanoceria exposure. Full article

Soil acidification in the subtropical region reduces soil productivity and increases the bioavailability of heavy metal(loid)s in soil. Here 800 °C-calcined oyster shell and leonardite-derived humic substance were combined to form a Ca-humic complex to remediate an acidic soil contaminated by cadmium (Cd) and arsenic (As) for safe vegetable production. In the pot experiment, the complex was added to soil as a soil amendment at 0%, 0.5%, 1.0%, 2.0%, and 5.0%. A 2.0% dose reduced Cd and As contents of the vegetable bok choy by 98% and 71%, respectively, alleviating the human health risk of Cd and As from the food chain. The unified bio-accessibility method (UBM) was followed to estimate the bio-accessibility of Cd and As. The complex at a 2.0% dose lowered soil Cd and As bio-accessibility in simulated gastric (BioG) and intestine (BioGI) compartments by 15.5% for BioG-Cd, 39.2% for BioGI-Cd, 28.8% for BioG-As, and 45.0% for BioGI-As, thus reducing the human health risk of Cd and As from soil ingestion. The use of oyster shell waste to produce Ca-humic complex as a soil amendment is a practical means of achieving dual agronomic and environmental benefits, from the remediation of soil contamination to the safe disposal of shell waste. Full article

Soil enzymes secure our food security; however, they are sensitive to abiotic stresses. Solving the global issues of food waste by implementing Sandwich compost can be a great solution to secure food security. Food waste Sandwich compost substrate (as soil treatment) and leachate (as seed priming agent and liquid fertilizer) were used to grow Bok Choy for four cycles, where soil pH, cation exchange capacity (CEC), moisture content, aggregate stability and enzyme activity were determined. All variables were positively corelated except catalase activity. Sandwich compost treatment significantly increased soil pH close to neutral and CEC. Anaerobic Sandwich compost-treated soil significantly reduced soil catalase activity. However, it gradually increased throughout the growing cycle. Sandwich compost treatment significantly maintained the aggregate stability along growing cycles. Hence, Sandwich compost substrate is recommended to improve soil quality in the aspects of pH, CEC and urease activity. Full article

Use of season extension tools such as high tunnels and diverse vegetable crops have been crucial in improving competitiveness of vegetable growers in Mississippi who operate on small- to medium-sized farms. Chinese cabbage, also known as pak choy or bok choy, has become increasingly popular due to numerous cultivar choices, fast maturity, high productivity, tolerance for frost, and its potential use for winter production in high tunnels in a subtropical climate. Five Chinese cabbage cultivars including ‘Asian Delight’, ‘Black Summer’, ‘Red Pac’, ‘Rosie’, and ‘Tokyo Bekana’ were evaluated for plant growth, yield, and mineral nutrient concentrations when grown with three types of biodegradable plastic mulches (BDMs) and one polyethylene (PE, or plastic) mulch in a high tunnel in two experiments from 30 October 2019 to 18 March 2020. The five tested cultivars varied in plant height, widths, leaf SPAD, fresh and dry plant weights, marketable yield, and macro- and micro-nutrient concentrations. ‘Tokyo Bekana’ produced the highest marketable yield and fresh and dry plant weights in both experiments. The three BDMs resulted in similar marketable yield and mineral nutrients in tested cultivars and similar temperatures of leaf, mulch, and substrate compared to the PE mulch. The high tunnel provides a viable way for the winter production of selected Chinese cabbage cultivars in a subtropical climate with possible different yields between production cycles due to varying microenvironment in those months. Full article

Corn flour-based porridge like dough, ugali, is the staple food of low-income population in sub-Saharan Africa. Lack of vitamin A, carotenoids, and dietary fibers brings about serious health issues to this population. In this study, vegetables including bok choy, broccoli, cabbage, carrot, Chinese onion stalk (C_onion), mushroom, are added during the cooking of ugali, as nutritional supplements. The freeze-dried powder of each vegetable was used for its long storage, stable nutrients, and similar particle size. Sub-Saharan African assessors were trained and sensory evaluated the six different vegetable fortified ugali with the plain, unfortified as the control on five attributes. The plain ugali was indistinguishable with the C_onion stalk fortified in color, with the carrot and C_onion stalk fortified in odor, with all vegetables (except broccoli and mushroom) fortified ugali in taste, with carrot and C_onion stalk fortified in granularity, and with cabbage, carrot, C_onion stalk fortified in viscosity. Preference ranking analysis showed that the C_onion stalk fortified ugali is even more favorably preferred than the plain, unfortified ugali, probably due to the umami components in C_onion that serve as the taste enhancer. This study indicates that Chinese onion stalk is a potential vegetable supplement to population in the sub-Saharan Africa. Full article