Maize Seeds Research Articles

Characterization of Paramagnetic Species in Seeds by Electron Paramagnetic Resonance (EPR)

Paramagnetic species were characterized in the seeds of radish wild, rice, mustard, wheat, oats, sorghum, sunflower, soybean, cotton, beans, maize and barley by Electron Paramagnetic Resonance (EPR). Some iron complexes such as goethite, hematite, magnetite, and ferrihydrite, normally present in the soil, were also investigated by EPR, since their signals can, a priori, be present in EPR spectra of seeds. The EPR experiments were performed at X-band microwave frequency (9.3 GHz) on the JEOL spectrometer (JES-PE-3X) from 77 to 385 K and on the BRUKER spectrometer (Elexsys E-580) in a temperature range from 30 to 70 K. In the EPR spectra of the seeds, it was detected the same complex of Fe3+ found in goethite, with g=2.0±0.1 in all the investigated seeds. In addition, free radicals have also been detected with g=2.004±0.002, on all seeds, and with g=2.013 only in sorghum seeds. The sunflower seeds showed the highest signal intensity of the free radical. During the temperature variation, changes were observed in the spectra, in a manner that at low temperature (30 K), beyond the higher intensity on signal of the goethite and free radical, the spectra of the seeds also showed signal of hematite and traces of Mn2+.

Alleviation of salinity stress by EDTA chelated-biochar and arbuscular mycorrhizal fungi on maize via modulation of antioxidants activity and biochemical attributes

Salinity stress adversely affects agricultural productivity by disrupting water uptake, causing nutrient imbalances, and leading to ion toxicity. Excessive salts in the soil hinder crops root growth and damage cellular functions, reducing photosynthetic capacity and inducing oxidative stress. Stomatal closure further limits carbon dioxide uptake that negatively impact plant growth. To ensure sustainable agriculture in salt-affected regions, it is essential to implement strategies like using biofertilizers (e.g. arbuscular mycorrhizae fungi = AMF) and activated carbon biochar. Both amendments can potentially mitigate the salinity stress by regulating antioxidants, gas exchange attributes and chlorophyll contents. The current study aims to explore the effect of EDTA-chelated biochar (ECB) with and without AMF on maize growth under salinity stress. Five levels of ECB (0, 0.2, 0.4, 0.6 and 0.8%) were applied, with and without AMF. Results showed that 0.8ECB + AMF caused significant enhancement in shoot length (~ 22%), shoot fresh weight (~ 15%), shoot dry weight (~ 51%), root length (~ 46%), root fresh weight (~ 26%), root dry weight (~ 27%) over the control (NoAMF + 0ECB). A significant enhancement in chlorophyll a, chlorophyll b and total chlorophyll content, photosynthetic rate, transpiration rate and stomatal conductance was also observed in the condition 0.8ECB + AMF relative to control (NoAMF + 0ECB), further supporting the efficacy of such a combined treatment. Our results suggest that adding 0.8% ECB in soil with AMF inoculation on maize seeds can enhance maize production in saline soils, possibly via improvement in antioxidant activity, chlorophyll contents, gas exchange and morphological attributes.

Detection of surface defects for maize seeds based on YOLOv5

The external appearance of maize seeds is one of important quality evaluation indicators for maize seeds. For traditional maize seed appearance quality detection, which mainly relies on naked eyes to inspect surface defects. Although computer vision as a relative mature way can be used for sample appearance quality inspection, manual feature extraction is still required. Meanwhile, machine learning technology, especially deep learning, has developed rapidly in the last decades. The maize seed surface defect detection coupled with deep learning can effectively replace traditional detection methods, reduce manual intervention, and decrease costs. In this paper, the collection and preprocessing of maize seed images, as well as the surface defects evaluation methods of maize seeds using a deep learning framework YOLOv5 were proposed. Firstly, in terms of image acquisition, maize seed batch surface defect detection system was established to obtain images. Then, the quality of maize seed images was improved by filtering, segmentation, and enhancement, which could significantly reduce noise in the images, separate the targets from the background and replace the background. Finally, ECA-Improved-YOLOv5S-Mobilenet model, which was established to improve the feature learning performance, could extracted the features from the maize seeds image and detect defects quickly at different levels. The experimental results showed that the precision was 92.8%, the recall rate was 98.9%, and the mPA0.5 was 95.5% with 8.8 MB of model size. In general, the proposed maize seeds surface defect detection method combined with deep learning could provide a theoretical support and technical basis for future development of seed grading and plantation.

Infectivity responses of Salmonella enterica to bacteriophages on maize seeds and maize sprouts

Salmonella enterica (S. enterica) is a major foodborne pathogen leading to a large number of outbreaks and bringing food safety concerns to sprouts. The control of S. enterica on maize sprouts is important because raw maize sprouts have been gaining attention as a novel superfood. Compared to conventional chemical methods, the applications of bacteriophages are regarded as natural and organic. This study investigated the effects of a 2 h phage cocktail (SF1 and SI1, MOI 1000) soaking on reducing the populations of three Salmonella enterica strains: S. Enteritidis S5-483, S. Typhimurium S5-536, and S. Agona PARC5 on maize seeds and during the storage of maize sprouts. The results showed that the phage cocktail treatment effectively reduced populations of S. enterica strains by 1–3 log CFU/g on maize seeds and decreased population of S. Agona PACR5 by 1.16 log CFU/g on maize sprouts from 7.55 log CFU/g at day 0 of the storage period. On the other hand, the upregulations of flagella gene pefA by 1.5-folds and membrane gene lpxA by 23-folds in S. Typhimurium S5-536 indicated a differential response to the phage cocktail treatment. Conversely, stress response genes ompR, rpoS, and recA, as well as the DNA repair gene yafD, were downregulated in S. Agona PARC5. This work shows the use of bacteriophages could contribute as a part of hurdle effect to reduce S. enterica populations and is beneficial to develop strategies for controlling foodborne pathogens in the production and storage of maize sprouts.

Protection of Stored Common Bean and Maize Grains Using Optimally Synthesized Biosilica from Rice Husk Ash

Losses provoked by insect pests on stored cereals and legumes contribute immensely to reduce food security, especially in rural communities in Sub‐Saharan Africa. The application of integrated control strategies, involving the use of synthetic pesticides, is often expensive and hazardous to humans and the environment. This study was conducted to optimize the production and use of biosilica from rice husk ashes, for the control of Sitophilus zeamais and Acanthoscelides obtectus, major insect pests of stored maize and common bean grains. The amorphous nature of the derived silica molecules coupled with the silanol and siloxane groups on their surfaces seemed to account for silica’s insecticidal effects on the pests, which were more on A. obtectus on common beans than S. zeamais on maize grains, with full mortalities obtained at doses of about 1.25 g per 50 g bean seeds and about 2.25 g per 50 g maize seeds, within 3 and 12 days, respectively. Similarly, the daily lethal dose (LD50) of silica powder required to obtain the mortality of half of the insects was lower on common beans than on maize seeds. The reduced phytotoxic activity of the biosilica on the stored common bean and maize grains indicates therefore that it could make an ecofriendly alternative to conventional protectants for small quantities of stored grains. However, large‐scale studies are needed in order to evaluate its potential use in grain storage systems.

Bayesian sequential estimation of the proportion of damage in maize seeds

Bayesian sequential estimation of the proportion of damage in maize seeds

Insect Pests and Diseases in Stored Sorghum (Sorghum bicolor L.) and Maize (Zea mays L.) in West Hararghe, Ethiopia

The presence of major insect pests and microflora in stored sorghum and maize in West Hararghe, Ethiopia, poses a significant threat to food security and agricultural productivity, leading to postharvest losses and economic hardship for local farmers. This study aimed to evaluate and identify the main grain insect pests and diseases of stored maize and sorghum in West Hararghe, Ethiopia. The survey was carried out in five major sorghum and maize‐producing districts of the surveyed areas, namely, Mieso, Gemechis, Tullo, Anchar, and Oda Bultum. The results revealed that maize and sorghum grains stored in sacks, ground pits, markets, and hanging (maize cob) storage containers were infested with insect species: maize weevil (S. zeamais), Angoumois grain moth (S. cerealella), rice weevil (S. oryzae), Red flour beetle (T. castaneum), confused flour beetle (T. confusum), and Lesser grain borer (R. dominica). The mean levels of major insect pest infestations and associated percentages of grain damage, weight loss, and germination loss were recorded across all traditional storage systems, including sacking, marketing, hanging or maize cob, and ground pit storage methods. The highest absolute frequency and relative frequency of F. oxysporum (14.53%), followed by A. flavus (13.08%), on maize seeds were recorded in the agar plate test. A total of eight species of fungi, including Fusarium species, A. parasiticus, and A. niger, were identified using the blotter and agar plate method. The incidence of fungal diseases was markedly high (98.33%) in maize grain stored in the Anchar district, followed closely by grain stored in the market in the same district, recording 98.33%. Therefore, it is recommended that further confirmatory identification using molecular tools be conducted to develop novel management strategies for these insect pests and diseases.

Improvement of N, P, and K availability of post-brick mining soil to increase maize yield by applying different types of biochar

The low fertility of post-brick mining soil may be improved by applying biochar to the soil because biochar is an excellent soil amendment, although its quality varies depending on the raw materials used. Therefore, soil fertility, nutrient availability, and crop yields are affected by the type and amount of biochar added to soils. This study examined the effect of types and dosages of biochar on nitrogen, phosphorus, and potassium availability of post-brick mining soil to increase maize yield. The treatment combinations of biochar dosages (0 t ha-1, 15 t ha-1, 30 t ha-1, and 45 t ha-1) and biochar types (coconut shell, wood, and rice husk biochars) were arranged in randomized block design with three replications. Each treatment plot measuring 4 m x 4.5 m was planted with maize seeds with a planting space of 80 cm x 25 cm. Urea (135 kg N ha-1), SP36 (36 kg P2O5 ha-1), and KCl (110 kg K2O ha-1) were applied as basal fertilizers. The results showed that at eight weeks after biochar application, the amount and type of biochar positively affected maize yield. The application of rice-husk biochar at 30 t ha-1 resulted in the highest maize yield. The application of each type of biochar at 45 t ha-1 yielded the highest increase in the availability of nitrogen, phosphorus, and potassium in the soil.

Effects of seed priming and foliar application of Se nanoparticles in the germination, seedling growth, and reproductive stage of tomato and maize

Sustainable approaches, such as nanotechnology-based strategies, are being researched to increase the productivity of crops. This study aimed to evaluate the effects of nanopriming with selenium nanoparticles (Se NPs) for tomato (Solanum lycopersicum) and maize (Zea mays). Additionally, the impact of Se NPs delivered through a foliar application during the reproductive stage of both crops was evaluated. The results showed that Se NPs inhibited the germination rate in maize by up to 100 % but increased the germination rate and vigor index in tomato by 50 and 208 %, respectively (at 10 ppm of Se NPs). Chlorophyll and proline contents were significantly affected in both crops (tomato and maize), suggesting that Se NPs activated the stress defense systems. In contrast, the foliar application of Se NPs on tomato in the reproductive stage increased the length and width of the stem by 10.8 and 4.3 %, respectively. The chlorophyll content increased by 30.8 % at 10 ppm of Se NPs. Additionally, the proline content of reproductive maize plants increased by up to 1303.6 %, indicating significant stressful conditions caused by the exogenous delivery of Se NPs. These results suggested that nanopriming seeds and foliar application of Se NPs positively impacted tomato. Conversely, the germination of maize seeds and the development of reproductive plants were severely inhibited by Se NPs.

Evaluation of Insecticidal Activity of Bioactive Compound Isolated from Seeds of Psoralea corylifolia L. on Maize Seeds Deteriorating Insect (Sitophilus zeamais M.)

Evaluation of Insecticidal Activity of Bioactive Compound Isolated from Seeds of Psoralea corylifolia L. on Maize Seeds Deteriorating Insect (Sitophilus zeamais M.)

Breeding strategies for quality protein maize: A Review

Zein proteins in maize seeds regulate food and feed quality and belong to several subfamilies. Most maize prolamin is α-zeins, which are rich in glutamine, leucine, and proline but lacking in critical amino acids (lysine and tryptophan). RNAi experiments show that 22kD zeins downregulate the quality protein maize (QPM) phenotype, not 19kD. The opaque-2 mutation caused a chalky, soft endosperm and many defects. QPM genotypes with opaque-2 alleles and firm kernels were improved. As opaque-2 is recessive and biochemical lysine and tryptophan analysis is costly, conventional backcrossing alone is not very useful. Markerassisted selection (MAS) allowed top inbreds to be homozygous o2o2 utilizing opaque-2 gene-specific markers. Vivek QPM-9, a mixture of two QPM introgression lines, benefits various clients and customers. This review highlights the breeding strategies for QPM.

Research on a Lightweight Method for Maize Seed Quality Detection Based on Improved YOLOv8

Research on a Lightweight Method for Maize Seed Quality Detection Based on Improved YOLOv8

An empirical and a dynamic-empirical model for the estimation of maize seedbed temperature

Soil temperature is the main factor in determining the germination of maize seeds and the emergence time of the crop. It controls the rate of phenological development while the meristem is underground, which is until the V6 (six leaf collar) stage of maize. The research performed by the authors aimed to model maize seedbed temperatures at sowing depth (soil temperature at 5 cm depth) during the sowing-emergence-early development period. The research is based on measurements in ploughed plots of the maize experiments at the Látókép Experiment Site of the University of Debrecen (Eastern Hungary) in two growing seasons of 2021–2022. Two types of empirical models were established, a multilinear regression model (M1) and a dynamic-empirical model (M2), where the daily increase and decrease of soil temperature are determined by multilinear regression. Candidates for input variables for both models were various, easily available daily meteorological parameters. M2 model performed better than M1 when applied to an independent database of 2022. This is particularly valid for the maximum and minimum soil temperatures. It was found that both M1 and M2 can be used to predict the soil temperature of the maize seedbed before shading by the plants. For daily mean temperature, M1 and M2 give a similarly good estimation, while the dynamic-empirical model has to be preferred for the maximum and minimum temperatures. M2, which is based on daily temperature, global radiation and wind speed data, predicts the daily mean (RMSE = 1.4 °C), maximum (RMSE = 2.2 °C), and minimum (RMSE = 1.6 °C) of seedbed temperature not worse than many earlier soil temperature models do, even hybrid or mechanistic ones with a large number of parameters.

Hyperspectral RGB Imaging Combined with Deep Learning for Maize Seed Variety Identification

Hyperspectral RGB Imaging Combined with Deep Learning for Maize Seed Variety Identification

Evaluation of biochemical component determinants for superior seedling performance in high-vigor maize seeds under accelerated aging stress

Evaluation of biochemical component determinants for superior seedling performance in high-vigor maize seeds under accelerated aging stress

Design and Fabrication of a Spiked-Shaft Maize Seed Separato

Maize shelling in developing and underdeveloped nations has been and remains a severe problem to its processing as it is tedious and requires more labour hours. This study aims to design and fabricate a motor-powered spike-shaft type Maize Seed Separator (MSS) machine. The design and selection of components like the motor, belt, frame, bearing, and shaft were made based on general design considerations. After the complete fabrication of the MSS machine, it was tested to find its shelling capacity and efficiency. The shelling capacity was found to be 220 kg/hr, which is 80 times faster than manual shelling and the maximum shelling efficiency was found to be 97 % at the feeding rate of 4 kg at a time. The machine consumes 1.28 kW of electricity, which, when operated for one hour,would cost about Rs. 14 per hour.

Enhancing Germination and Seedling Growth in Salt Stressed Maize Lines through Chemical Priming

This study aimed to investigate the tolerance level and the use of primers (H2O, KNO3, ascorbic acid and salicylic acid), in mitigating stress in maize in the newly released cultivars (SWAN-LSR-Y, BR9928-OMR-SR-Y and OMR-LSR-SY). Activities of SOD, APX, CAT and GSH and lipid peroxidation were investigated, to measure the biochemical response of the primed maize seeds. Maize seeds primed with KNO3 and ascorbic acid improved germination and anti-oxidative potential against ROS in ameliorating the salinity stress, while salicylic acid slowed germination. The same trend was followed in the seed vigour index and radicle length of seeds primed with ascorbic acid, which recorded the highest values. The control was observed to have the highest seed vigour index, while seeds primed with salicylic acid showed the least vigour index in the maize seeds. Increased salinity stress showed adverse effects on all growth parameters. Of the maize cultivars tested, SWAN-LSR-Y showed the most tolerance to salinity stress, in terms of germination. Significant high enzymatic activities and lipid peroxidation were recorded in seeds primed with ascorbic acid and KNO3 show their importance in plant metabolic activities.

Nourishing the farms, nourishing the plates: Association of climate‐smart agricultural practices with household dietary diversity and food security in smallholders

AbstractClimate‐smart agricultural (CSA) practices are increasingly being promoted as nature‐based solutions to improve the livelihoods of smallholder farm households amid a sharp increase in climate‐change anomalies. However, the extent to which CSA practices contribute to smallholder food security and dietary diversity remains unclear. In this study, we use panel and nationally representative data from Tanzania to examine the association between two climate‐smart agricultural practices, namely, improved maize varieties and maize‐legume intercropping, and food security in smallholder farm households. We use maize yield per acre, adult‐equivalent food expenditure, and household dietary diversity scores to measure household food security, representing three of the four food security pillars: availability, access, and utilization. We also examine the complementarity and potential advantages of combining improved maize seeds with fertilizers. Using standard panel data estimation approaches, we find a positive association between the adoption of improved maize varieties and maize‐legume intercropping and an increase in food production measured through higher crop productivity. However, we do not find a corresponding improvement in household dietary diversity or increased food expenditure, despite the higher crop production. Several factors might explain this outcome, including the challenges faced by farmers in accessing markets to sell surplus produce, the influence of established dietary habits, gender issues, and other local factors that promote the consumption of cereal‐based foods such as maize. Our findings suggest that CSA practices may help improve food production and availability, but more effort is needed to translate increased food production into improved dietary diversity and better food security among smallholder farmers in sub‐Saharan Africa. [EconLit Citations: C23, D12, D13, D24, Q12, Q16, Q18, Q54].

Effects of microwave treatment on the microstructure, germination characteristics, morphological characteristics and nutrient composition of maize

This study investigated the effects of microwave treatment on the microstructure and germination characteristics of maize seeds, as well as the morphological characteristics and nutritional composition of germinated maize. The results indicated that microwave could alter the microstructure of endosperm cells in maize seeds. Microwave enhanced the germination rate and shortened the average germination time. Besides, the sprout length (20.0 %), fresh weight of edible parts (14.0 %) and reducing sugar content (6.04 %) of germinated maize were significantly increased by microwaving of 200 W/20 s, compared with CK (10 d). In addition, the respiratory rate (41.5 %) and free amino acids content (19.5 %) of germinated maize were also significantly enhanced with microwave of 200 W/20 s, compared with CK (7 d). Microwave could significantly increase amylase activity, accelerate starch hydrolysis, and greatly decrease starch content. For soluble protein and fat content of germinated maize, there were no significant differences among the treatment groups. Correlation analysis showed that the sprout length and fresh weight of germinated maize were highly correlated with their nutritional components. Therefore, microwave can be an effective method to improve the nutritional value of germinated maize.

The maize ATP-binding cassette (ABC) transporter ZmMRPA6 confers cold and salt stress tolerance in plants.

ZmMRPA6 was cloned and characterized as the first ATP-binding cassette (ABC) transporter in maize to be proven to participate in cold and salt tolerance. Homologous genes AtABCC4 and AtABCC14 of ZmMRPA6 also responded to salt stress. ATP-binding cassette (ABC) proteins are major transmembrane transporters that play significant roles in plant development against various abiotic stresses. However, available information regarding stress-related ABC genes in maize is minimal. In this study, a maize ABC transporter gene, ZmMRPA6, was identified through genome-wide association analysis (GWAS) for cold tolerance in maize seeds germination and functionally characterized. During germination and seedling stages, the zmmrpa6 mutant exhibited enhanced resistance to cold or salt stress. Mutated of ZmMRPA6 did not affect the expression of downstream response genes related cold or salt response at the transcriptional level. Mass spectrometry analysis revealed that most of the differential proteins between zmmrpa6 and wild-type plants were involved in response to stress process including oxidative reduction, hydrolase activity, small molecule metabolism, and photosynthesis process. Meanwhile, the plants which lack the ZmMRPA6 homologous genes AtABCC4 or AtABCC14 were sensitive to salt stress in Arabidopsis. These results indicated that ZmMRPA6 and its homologous genes play a conserved role in cold and salt stress, and functional differentiation occurs in monocotyledonous and dicotyledonous plants. In summary, these findings dramatically improved our understanding of the function of ABC transporters resistance to abiotic stresses in plants.