Maize Grain Research Articles

The effect of different levels of liquid organic compost of Chromolaena odorata on production, nutrient composition, and In Vitro digestibility of hydroponic maize fodder

The aims of the present study were to evaluate the addition of different levels of liquid organic compost of Chromolaena odorata (CO) in hydroponic media on production, nutrient composition, and in vitro digestibility of hydroponic maize fodder. Maize grains were obtained from the local market and grown hydroponically in the media. The study was design following a completely randomized design with 5 treatments and 4 replications. The treatments were: CR 0 = without liquid organic compost; and with liquid organic compost of 25 ml (CR 1); 50 ml (CR 2); 75 ml (CR 3); 100 ml (CR 4). The liquid organic compost of Chromolaena odorata used was fermented for 21 days before application into the fodder. Maize fodder was grown hydroponically for 7 days before being harvested. Data obtained from this study were analyzed using ANOVA of SPSS 25. Addition of liquid organic compost of Chromolaena odorata had a significant effect on increasing (P<0.05) fodder height, leaf length, leaf width, fresh weight, and dry weight. Similarly increasing the level of liquid organic compost of Chromolaena odorata significantly improved In vitro dry matter digestibility, organic matter digestibility, VFA, and NH3. However, there was no different between treatments (P>0.05) on root length. In conclusion, the addition of different levels of liquid organic compost of Chromolaena odorata increased maize production, nutrient composition and in vitro digestibility of hydroponic maize fodder.

Enhanced efficiency nitrogen fertilizers (EENFs) can reduce nitrous oxide emissions and maintain high grain yields in a rain-fed spring maize cropping system

ContextEnhanced efficiency nitrogen fertilizers (EENFs) have provided opportunities for the simultaneous mitigation of nitrous oxide (N2O) emissions and increases in crop productions. However, the practice of combining EENFs with optimal fertilization under conditions of misaligned water and fertilizer inputs in rain-fed spring maize systems remains inadequately understood. ObjectiveThis study aims to determine the factors controlling N2O emissions under the soil climatic conditions in rain-fed plastic mulching cropping systems treated with different nitrogen (N) fertilization rates and EENFs, and to determine the most effective N fertilization measure to reduce N2O emissions while maintaining crop yields. MethodsA 3-year field experiment was conducted in a spring maize system located in the semiarid rain-fed region of the Loess Plateau, applying two types of EENFs: a nitrification inhibitor dicyandiamide (DCD) and a slow-release fertilizer (SRF). It comprised five fertilization treatments: unfertilized (CK), conventional N rate (CON, 200 kg N ha−1), optimal N rate (OPT, 160 kg N ha−1), OPT with the addition of DCD (OPT+DCD), and OPT using SRF (OPT-SRF). ResultsThe average annual cumulative N2O emissions over the 3-year experimental period ranged from 0.74 to 1.87 kg N2O-N ha–1. Fertilizer N contributed 26−60% to annual N2O emissions. The highest N2O fluxes (50–161 μg N2O-N m–2 h–1) typically occurred within the initial 10 days following fertilization, likely induced by strong nitrification processes, constituting 12–19% of the annual N2O emissions during this brief period. In comparison to the CON treatment, the OPT, OPT+DCD, and OPT-SRF treatments resulted in significant reductions in annual N2O emissions of 24%, 46%, and 34%, respectively, without causing any significant decrease in maize grain yields. The application of DCD led to increased ammonium (NH4+-N) concentrations while reducing nitrate (NO3–-N). Conversely, using SRF resulted in a decrease in both NH4+-N and NO3–-N concentrations. ConclusionsUsing EENFs at the ideal fertilization rate significantly curtailed yearly N2O emissions without adversely affecting maize yields in a rain-fed plastic mulching spring maize system prevalent in the Loess Plateau. Most N2O emissions occurred post-fertilization, with rainfall events further influencing these emissions. ImplicationsOur findings recommend the incorporation of nitrification inhibitors, such as DCD, as the most effective fertilizer measure for reducing N2O emissions in the rain-fed region of the Loess Plateau.

Maize grain filling characteristics in China: Response to meteorological factors

To investigate the dynamic changes in dry matter accumulation in maize after anthesis, we established a logistic model to describe grain filling characteristics (GFC), and analyzed differences between spring and summer maize, and the influence of meteorological factors. The results showed that the logistic model accurately simulated the dynamic changes in grain growth. For spring maize, the fitted hundred-grain weight at maturity was closely related to the average grain filling rate until maturity, days of the active grain filling period, time of the maximum grain filling rate, and duration of the rapid increase in grain weight. For summer maize, it was closely related to the time of the maximum grain filling rate, days of active grain filling period, duration of gradual grain weight, and the rapidly increasing period. The filling characteristics of spring and summer maize differed because of the different meteorological conditions and biological characteristics. The grain filling duration of spring maize was longer than that of summer maize. The maximum grain filling rate of spring maize occurred later than that of summer maize. Temperature and precipitation were the main meteorological factors affecting the hundred-grain weight of spring maize, whereas temperature was the main factor affecting summer maize. The response of spring maize GFC to meteorological factors was more complex than that of summer maize. These results are important for the development of appropriate strategies for improving maize productivity in China.

Brown manuring in maize (Zea mays): Effects on weed interference and crop productivity

A field experiment was undertaken during rainy (kharif) season 2017 at ICAR-Indian Agricultural Research Institute, New Delhi to study the effects of brown manuring on weeds and maize (Zea mays L.) productivity. Season-long weed infestation (~unweeded control) resulted in the highest reduction (~41%) in grain yield of maize. Among the brown manuring (BM) treatments, growing of 1:1 mixture of Sesbania bispinosa (12.5 kg seed/ha) + Crotalaria juncea L. (12.5 kg seed/ha) supplemented with 2,4-D 0.5 kg/ha applied at 35 DAS, resulted in the highest reduction in weed density (~93%) and dry matter (~94.4%). This BM, in these regards, was comparable with the atrazine + hand weeding (HW) at 35 days after sowing (DAS) and weed-free control treatments. All BM treatments suppressed noxious weed Cyperus rotundus, which was poorly or not controlled by the recommended tank-mixture of atrazine and pendimethalin. Weed-free control resulted in the highest values of maize plant dry-matter (~210.6 g/plant), cob weight (~155.9 g/cob), and grain yield (~6.0 t/ha). The atrazine + HW, Sesbania + Crotalaria (12.5 + 12.5 kg/ha) mixture applied with 2,4-D 0.5 kg/ha at 25 DAS, Sesbania 25 kg/ha with 2,4-D 0.5 kg/ha at 25 DAS, and pendimethalin 0.75 kg/ha + atrazine 0.75 kg/ha treatments were comparable with weed-free control on maize grain yield.

Evaluation of saline water effects on use efficiency and soil nutrient availability of maize (Zea mays L.) under drip fertigation

A field experiment was conducted during the rabi season of 2022-23 at the Saline Water Scheme, Agricultural College Farm, Bapatla. The study’s objective was to evaluate the effects of saline water on nutrient use efficiency and soil nutrient availability in maize under drip fertigation. The experiment consisted of eight treatments and four replications, arranged in a randomized block design. Irrigation with the best available water along with the application of a recommended dose of fertilizer (240-80-80 NPK kg ha-1) recorded the highest uptake of N (88.2 and 62.4 kg ha-1), P (21.2 and 16.20 kg ha-1), and K (25.4 and 126.7 kg ha-1) in grain and stover of maize, respectively, which were at par with the alternate use of fresh water with saline water of 2 dS m-1. Nutrient use efficiencies, i.e., agronomic efficiency (7.4, 18.4, and 18.4 kg kg-1), physiological efficiency (85.2, 225.3, and 159.4 kg kg-1), apparent recovery efficiency (22.5, 17.0 and 48.7 %) and utilization efficiency (15.7, 39.1 and 39.1 kg kg-1) of N, P, and K, respectively, were also observed to be the highest under irrigation with the best available water along with a recommended dose of fertilizer application. Soil pH remained unaffected with saline water irrigation, whereas the EC of the soil was the highest under irrigation with saline water of 4 dS m-1 without the application of fertilizers. Soil-available nitrogen, phosphorous, and potassium were most elevated under irrigation with the best available water, with values of 152.5, 36.3, and 352.8 kg ha-1 respectively. The lowest values of nutrient uptake, nutrient use efficiencies, and soil available nutrients were recorded under irrigation with a water salinity of 4 dS m-1 without applying fertilizers. The use of a cyclical approach in utilizing both freshwater and saline water has demonstrated its effectiveness in mitigating the adverse effects of salts, resulting in enhanced efficiency in nutrient utilization and greater accessibility of soil nutrients.

Improving resilience to high temperature in drought: water replenishment enhances sucrose and amino acid metabolisms in maize grain.

Heat stress poses a significant threat to maize, especially when combined with drought. Recent research highlights the potential of water replenishment to ameliorate grain weight loss. However, the mitigating mechanisms of heat in drought stress, especially during the crucial early grain-filling stage, remain poorly understood. We investigated the mechanism for mitigating heat in drought stress by water replenishment from the 12th to the 32nd days after silking in a controlled greenhouse experiment (Exp. I) and field trial (Exp. II). A significant reduction in grain weight was observed in heat stress compared to normal conditions. When water replenishment was applied to increase soil water content (SWC) under heat stress, the grain yield exhibited a notable increase ranging from 28.4 to 76.9%. XY335 variety was used for transcriptome sequencing to analyze starch biosynthesis and amino acid metabolisms in Exp. I. With water replenishment, the transcripts of genes responsible for trehalose 6-phosphate phosphates (TPP), alpha-trehalase (TRE), ADP-glcpyrophosphorylase, and starch synthase activity were stimulated. Additionally, the expression of genes encoding TPP and TRE contributed to an enhanced conversion of trehalose to glucose. This led to the conversion of sucrose from glucose-1-phosphate to ADP-glucose and ADP-glucose to amylopectin, ultimately increasing starch production by 45.1%. Water replenishment to boost SWC during heat stress also elevated the levels of essential amino acids in maize, including arginine, serine, tyrosine, leucine, glutamic acid, and methionine, providing valuable support to maize plants in adversity. Field trials further validated the positive impact of water replenishment on SWC, resulting in a notable increase in grain yield ranging from 7.1 to 9.2%. This study highlights the vital importance of adapting to abiotic stress and underscores the necessity of developing strategies to counteract its adverse effects on crop yield.

Seasonal variation and uptake pattern of heavy metals in maize

The detrimental impact of heavy metals on human health necessitates a focus on their contamination in the food chain. Heavy metals possess carcinogenic, mutagenic, teratogenic, and endocrine-disrupting properties. The objective of the study was to ascertain how Zn, Pb, Cd, Ni, Co, Cu, Cr, and Hg are accumulated in the roots and grains of maize samples cultivated under the Kano River Irrigation Project during both wet and dry seasons production and subsequently compare the levels of these heavy metals with the recommended permissible limits established by FAO/WHO. Additionally, the research sought to employ Translocation Factors to examine the uptake pattern of heavy metals in maize during the two growing seasons. Maize samples were procured from 10 different locations within the irrigation scheme during 2022 wet season and 2023 dry season harvests. The samples were prepared using standard laboratory protocols and heavy metals were determined using atomic absorption spectrophotometer. The heavy metals accumulation in maize grains was found in the order Zn&gt;Cu&gt;Pb&gt;Ni&gt;Co during wet season production. Cd, Cr, and Hg were not detected in samples collected during the wet season. It is only the concentration of Zn that exceeded the permissible limit in the samples collected during wet season production. The accumulation order during the dry season was Zn&gt;Cu&gt;Cr&gt;Pb&gt;Ni&gt;Co&gt;Cd. Hg was not detected in all the maize grain samples. The concentrations of Zn, Pb, Cd and Cr exceeded permissible limits in maize grains samples collected during dry season production.

Enhancement of Nutritional Substance, Trace Elements, and Pigments in Waxy Maize Grains through Foliar Application of Selenite.

Selenium (Se) is a micronutrient known for its essential role in human health and plant metabolism. Waxy maize (Zea mays L. sinensis kulesh)-known for its high nutritional quality and distinctive flavor-holds significant consumer appeal. Therefore, this study aims to assess the effects of foliar Se spraying on the nutritional quality of waxy maize grains, with a focus on identifying varietal differences and determining optimal Se dosage levels for maximizing nutritional benefits. We employed a two-factor split-plot design to assess the nutritional quality, trace elements, and pigment content of jinnuo20 (J20) and caitiannuo1965 (C1965) at the milk stage after being subjected to varying Se doses sprayed on five leaves. Our findings indicate superior nutrient content in J20 compared to C1965, with both varieties exhibiting optimal quality under Se3 treatment, falling within the safe range of Se-enriched agricultural products. JS3 (0.793) demonstrated the highest overall quality, followed by JS2 (0.606), JS4 (0.411), and JS1 (0.265), while CS0 had the lowest (-0.894). These results underscore the potential of foliar biofortification to enhance the functional component contents of waxy maize grains.

Direct nitrous oxide emissions from a crop rotation of maize and mung bean after different long-term fertilizer applications in Thailand

Nitrous oxide (N2O) is a greenhouse gas primarily released by fertilizers used in crop cultivation. In Thailand, cropland occupies the majority of the arable land but studies on N2O emissions from cropland remain scarce. The present study aimed to evaluate the N2O emissions, soil characteristics, and crop productivity resulting from different long-term fertilizer applications in a crop rotation of maize and mung bean. A long-term experimental field managed through crop residue incorporation combined with different fertilizer applications over 45 years was utilized in this study. It consisted of four distinct treatments: no fertilizer (CON), 134 kg N ha−1 from organic fertilizer (ORG), 188 kg N ha−1 from chemical fertilizer (CHE), and 322 kg N ha−1 from a combination of organic and chemical fertilizers (OAC). Long-term application of chemical fertilizer induced soil acidification, whereas the use of organic fertilizer maintained soil pH and enhanced soil carbon accumulation. Results showed that the OAC, CHE, and ORG practices significantly (p < 0.05) increased direct N2O emissions from the soil, particularly during the maize cultivation period. Annual cumulative N2O emissions were enhanced on average by 204 % (3.22 kg N2O ha−1) in OAC, 181 % (2.98 kg N2O ha−1) in CHE, and 79.4 % (1.90 kg N2O ha−1) in ORG compared with CON (1.06 kg N2O ha−1), indicating that larger N input rates induced larger N2O emissions. Chemical fertilizer induced significantly (p < 0.05) larger and faster N2O emissions than organic fertilizer. When considering N2O emissions per N application rate in all treatments as the emission factor, the use of N fertilizers combined with crop residues in the soil over two years averaged 0.61 % (± 0.13 %). This value was approximately 39 % lower than the default value recommended by the Intergovernmental Panel on Climate Change, which is currently used in Thailand. The consecutive addition of fertilizers significantly (p < 0.05) increased maize grain yield compared with the CON. However, no significant differences were observed among the various fertilizer treatments. Despite all fertilizer applications induced larger N2O emissions, they also produced greater crop yields. Consequently, this study recommended the practice of ORG as a means to mitigate emissions without compromising crop yield and soil quality.

Assessing several fungal contaminants and their associated mycotoxins in maize cultivated on cornfields of Republic of Moldova

Maize is an important crop for the Republic of Moldova and one of the crops most contaminated with mycotoxins. Maize grain obtained from plants cultivated on Moldavian cornfields in 2021 and 2022 were tested for mycotoxigenic risk using qPCR with primers to several fungal genome sequences engaged in mycotoxin synthesis and ELISA test to screen total aflatoxins, fumonisin B1, zearalenone, deoxynivalenol and T-2 toxin. Except for T-2 toxin, the mycotoxin concentrations were under the limits of detection and did not exceed maximum admissible levels for unprocessed grain. Concentrations of T-2 toxin in grain samples did not correlate significantly with the quantity of toxigenic F. sporotrichioides. All of the analysed grain samples were contaminated with at least one toxigenic fungus, and 20% of the samples were infected with seven different species of toxigenic fungi. Accumulation of fungi in maize kernels was affected significantly by the season, and generally a decrease was observed in fungal frequency and quantity under drought conditions. However, several toxigenic Aspergillus and Fusarium fungi that are able to produce aflatoxins and fumonisins under improper storage conditions were found in the kernels during the whole period of monitoring.

Impact of different water regimes on maize grown at two distinctive pedo-climatic locations in Bosnia and Herzegovina

Aim of study: A two-year experiment (2021-2022) was conducted to assess the response of a local maize hybrid BL-43 to different water regimes (full irrigation, deficit irrigation and rainfed) at two distinguished pedo-climatic locations (Aleksandrovac and Butmir) in Bosnia and Herzegovina (BiH).&#x0D; Area of study: The field experiment was located in Aleksandrovac (near Banja Luka) and Butmir (near Sarajevo) in BiH.&#x0D; Material and methods: A randomized block design was adopted at both experimental locations with three replicates. An Excel-based irrigation tool was used to manage crop water requirements and irrigation scheduling.&#x0D; Main results: Crop response to water was affected by site-specific agronomic management, the duration of phenological stages and their interconnection with precipitation events. At both locations, the effect of the water inputs on grain yield was statistically significant confirming the beneficial impact of irrigation. The effect of water stress on yield was particularly pronounced at Aleksandrovac, which was under water and temperature stresses during flowering time. During both seasons and for all water regimes, the total average grain yield was greater at Butmir than at Aleksandrovac for 38% and 27%, respectively.&#x0D; Research highlights: This is the first experimental study conducted in BiH on the effect of irrigation on maize grain production under different pedoclimatic conditions. The study emphasizes the need for knowledge regarding the impacts that climate change is having on the productivity of one of the region's most important crops.

Different Management of Nitrogen Application Affected Growth Characteristic of Maize (Zea mays L)

A field study was conducted during Kharif 2019-20 at Professor Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, Hyderabad, Telangana, India to evaluate different handheld decision support tools for precision nitrogen management in rainfed maize (Zea mays L.). The study utilized a randomized block design and was replicated three times. The eight treatments included applying nitrogen through the State-recommended dose of 200 kg ha-1 in three splits (RDN), using a leaf color chart (LCC) based on N at thresholds 3 and 4, using a soil plant analysis development (SPAD) chlorophyll meter based on N at thresholds 35 and 40, and using a Green Seeker based on N at NDVI 0.6 and 0.8 in comparison with RDN and absolute control. Based on Green Seeker NDVI at threshold 0.8, the results showed that applying nitrogen resulted in considerably greater yields for maize grain (8408 kg ha-1), stover (9923 kg ha-1), and harvest index (45.8%). with higher yield and growth parameter viz., test weight (36.3 g ), No. of grain rows row-1 (36.7), cob length (18.9 cm), plant height (223.7 cm), leaf area (6385.75 cm2) and dry matter accumulation (18193 kg ha-1) as compared to RDN. Similarly, Green Seeker based N at NDVI 0.8 also registered higher net returns (Rs. 118961 ha-1) and B: C ratio (4.05).

Consequential LCA of NPK fertilizers from microbial, animal, plant, and mineral origin highlights resource constraints and environmental impacts

The production and use of mineral fertilizers lead to severe environmental impacts, therefore initiatives such as the European Green Deal promote organic farming and nutrient circularity. However, many organic fertilizers (those containing organic carbon and nutrients of exclusively biological origin) face constraints due to resource availability, and it is paramount to understand their environmental impacts to prevent unforeseen effects. This study employed a consequential life cycle assessment (LCA) to compare the environmental impact of mineral fertilizer to three types of organic fertilizers: animal-, plant-, and innovative microbe-based, considering market constraints and marginal suppliers. Organic fertilizers were complemented with mineral products to yield NPK compound fertilizers containing 1 t of nitrogen, 0.44 t of phosphorus, and 0.83 t of potassium (multi-substance functional unit). The findings reveal that 9 out of the 17 studied organic fertilizers are constained products, and that their demand is met through the supply of mineral fertilizers, soybean meal, and maize or barley grain. Consequently, for the transition to a circular and organic agrifood system, the focus should shift toward untapped resources like microbial fertilizers sourced from food and beverage industry wastewater, and sewage sludge. Constrained markets vary with time and geographical location, emphasizing the importance of context-specific decision-making. The impact of mineral fertilizers is relatively low across impact categories, but the gap between them and energy-intensive organic fertilizers narrows in an industrial symbiosis scenario where waste heat is available. An additional assessment of soil organic carbon estimated the contribution of organic fertilizers to the “4 per 1000" initiative's goal for soil carbon storage. Organic fertilizer application alone only achieves this goal in one scenario (rapeseed meal), but combining it with other management practices like crop rotation offers a promising strategy. The scenario that included fertilizer transport showed the potential for reduced environmental impacts by applying locally available by-products as organic fertilizer instead of imported mineral fertilizers. Overall, the results call for caution when transitioning from mineral to organic fertilizers as their availability and environmental impact are not self-evident.

Microbiological Safety and Nutritional Adequacy of Composite Porridge Flour Used in a Selected School-Feeding Program in Kamuli District, Uganda

By providing nutrient-enriched meals, the Iowa State University-Uganda Program plays a crucial role in combating hunger and improving school attendance by pupils in Kamuli district, Uganda. The lunchtime meals for pupils in primary grades 3 to 7 consist of a blend of maize grains and beans cooked together with vegetables and eggs to enhance their nutritional value. The program introduced a new composite porridge flour (44% maize, 26% millet, and 18% amaranth grain) for feeding pupils from kindergarten to primary grade 2 at break time. However, the microbiological safety of the flour for making the porridge had yet to be assessed. Additionally, though the proportions of the flour ingredients were known, its proximate composition and energy density were unknown. Hence, the porridge’s contribution to each pupils recommended dietary allowance had never been evaluated for adequacy. This study, therefore, assessed the microbiological safety and nutritional adequacy of the composite flour (n = 5 batches). Fungal contamination was determined by spread plating on acidified Potato Dextrose agar. Aflatoxin concentrations were determined by Liquid Chromatography Tandem Mass Spectrometry. Proximate composition was determined following standard methods. Gross energy was estimated using the energy conversion factors. To evaluate nutritional adequacy, the contribution of the porridge flour to pupils’ RDA was compared with the 1998 FAO/WHO RDA guidelines. The mean fungal count (4.4 ± 0.1 log cfu/g) slightly exceeded the acceptable maximum limit (4 log cfu/g), although no aflatoxins were detected, thus indicating satisfactory microbial safety. The flour predominantly contained carbohydrates (81.0% ± 0.7), moderate amounts of protein (8.2% ± 0.1), and crude fat (7.6% ± 0.5) alongside minimal levels of total ash (1.8% ± 0.1) and crude fiber (1.7% ± 0.6). Its contribution to the pupils’ RDA was very minimal owing to the low porridge intake (about 10 g dry matter per pupil per day). Therefore, there is an urgent need to enhance the nutrient profile of the composite flour by incorporating more protein and fiber rich ingredients and increasing the serving size to meet the dietary needs of the pupils. The flour could also be extruded to ensure a higher bulk density of the porridge.

Trait‐dependent plasticity erodes rapidly with repeated intergenerational acclimation in an invasive agricultural pest

AbstractClimate change is associated with increased mean temperatures and amplitudes manifesting both acutely and chronically, triggering organism stress responses that confer fitness costs and/or benefits. The larger grain borer (LGB), Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) is an invasive postharvest agricultural pest. While host shift is its well‐known potential invasive mechanism, how repeated intergenerational stress environments may influence offspring phenotypes is largely unknown. We thus evaluated physiological and ecological performance of LGB following repeated intergenerational acute heat acclimation to insinuate its likely responses to projected increased bouts of heat stress associated with climate change. Parental colonies were acutely heat‐acclimated separately at 35°C and 38°C; 80% RH for 2 h in climate chambers and released onto sterilized maize grain at optimal conditions (32°C, 80% RH). The F1 progenies were, respectively, acclimated at the same conditions and incubated to F2 generation. We then evaluated physiological and ecological performance under optimal conditions across parental, F1 and F2 generations. Our results showed that plasticity was highly trait dependent, and that acclimation did not affect F1 and F2 critical thermal maxima, but did improve critical thermal minima. However, while acclimation improved heat knockdown time at F1, repeated acclimation significantly reduced heat knockdown times at F2, suggesting plasticity erosion with generational repeated acclimations. Acute acclimation negatively affected ecological performance of F1 generations although this was restored with repeated acclimation in F2 populations. Our results suggest that the LGB may inflict more economic damage with repeated heat stress due to generational adaptation to temperature stress. The results contribute to knowledge on pest forecasting modelling under changing climates and provides a framework for phytosanitary adjustments in heat treatment protocols for international grain trade.

Effect of Moringa oleifera Leaf Powder and Seed Oil on Insect Pests of Stored Maize and Cowpea

The leaf powder of Moringa oleifera was applied as direct admixture at 5g, 10g and 15g while the seed oil was applied at 5ml and 10ml to 100g each of Maize and Cowpea grains respectively, while the control was without insecticide application to test for insect mortality., progeny development and damage caused on stored maize and cowpea (Sitophilus zeamais and Callosobruchus maculatus). The experiment was laid out in a Completely Randomized Design (CRD) and results obtained were subjected to analysis of variance (ANOVA) while means were separated using the Least Significant Difference (LSD). The result showed significantly (P&lt;0.05) progeny reduction of adult Sitophilus zeamais and Callosobruchus maculatus using Moringa oleifera leaf powder at different concentration 0, 5g (23.90, 28.62), 10g and 15g respectively. Control (0) recorded the highest number 68.51 in Callosobruchus maculatus, and 56.85 in Sitophilus zeamais. Mortality test result showed that moringa leaf powder significantly(P&lt;0.05) increased the mortality of adult S. zeamais and C. maculatus with increase in concentration after 96 hours of exposure while moringa seed oil offered 100% mortality after 24 hours of exposure. Germination of maize and cowpea was not affected after treatment with moringa leaf powder and seed oil. Contact toxicity result showed significant adult mortality of S. zeamais and C. maculatus on filter paper with 15% mortality in C. maculatus and 10% in S. zeamais. Damage was significantly reduced in treated grains compared with the untreated control. Moringa seed oil was more toxic to S. zeamais and C. maculatus compared to moringa leaf powder and the untreated control. The protective effect of moringa seed oil against S. zeamais and C. maculatus comes principally through oviposition suppression and reduced or complete inhibition of adult emergence, consequently reducing or eradicating infestation risk, damage and loss of maize and cowpea grains in storage. While the use of plant essential oils against storage insect pest is being advocated, the availability, affordability and the tendency of tainting protected grains should be considered.

Functional transgenes in Mexican maize: benefits and risks for insect pest management in Mexico and the United States

Abstract Corn earworm (Helicoverpa zea) and fall armyworm (Spodoptera frugiperda) are major migratory pests of maize (Zea mays) in the United States and Mexico. They are primarily controlled in the United States with genetically engineered (GE) maize, while the 25-yr moratorium on cultivating GE maize in Mexico has forced growers to control these pests with insecticides, where maize productivity remains 35% below the world’s average. The United States annually exports 5% of its maize grain to Mexico, where it provides human food and animal feed. This seed is often sown by smallholder growers, leading to plantings of GE transgene-expressing maize and potential hybridization with local landraces. As a result, transgenes are now present in Mexican maize products and landraces. In this study, we examined the F1 offspring of GE maize to better understand the frequency of different transgenes expressed in maize seeds exported to Mexico. We show that exported seed contains numerous transgenes, including an estimated ~68% epsps expressing resistance to the herbicide glyphosate; ~80% pat and bar expressing resistance to the herbicide glufosinate; and ~82% Bacillus thuringiensis (Bt) genes that effectively protect maize plants from several insect pests. We tested 134 samples, including landraces from 10 Mexican states, and found that 35% expressed resistance to glyphosate and 33% to glufosinate. Many samples containing herbicide resistance also expressed 11%–100% functional Bt transgenes, which can effectively reduce the refuge area provided by Mexican maize and increase the Bt-resistant allele frequency. We discuss ways that the introgression of transgenes could provide pest management benefits to Mexican growers but, at the same time, accelerate the development of Bt-resistance in corn earworm and fall armyworm. Our cost-effective screening methods can be used to determine the introgression of functional herbicide resistance and Bt transgenes in maize.

Construction of Maize Threshing Model by DEM Simulation

This paper proposes a modeling method of maize in threshing. The static friction coefficient and rolling resistance coefficient of the maize grain were measured using the slope method. The maize grain stacking angle test was designed using the central composite design response surface test. A regression model was established based on the simulation results to find the best combination. The results suggested that the modeling method proposed in this paper was effective in improving the accuracy of maize grain simulation compared with previous methods. Furthermore, this paper presents a method to verify the feasibility and reliability of the maize grain cob discrete element model using the distribution of grain in the granary and the final removal rate as the verification method. The results of the actually simulated threshing test were analyzed using a Wilcoxon signed-rank test, heat map analysis, and the Spearman’s rank correlation coefficient. It was found that the DEM model of maize cob is suitable for simulating the maize threshing process. This can aid in further research on the subject.

Exogenous maize grain embryonic extract enriched with some biostimulants confers drought stress tolerance by promoting tomato's growth, photosynthetic efficiency, antioxidant defense, and yield and quality.

Exogenous maize grain embryonic extract enriched with some biostimulants confers drought stress tolerance by promoting tomato's growth, photosynthetic efficiency, antioxidant defense, and yield and quality.

Water productivity at two sowing dates of simple white grain maize hybrids

In Mexico, maize stands out for its economic, food and cultural importance. Since ancient times, attempts have been made to increase maize grain yields with different alternatives, including hybridization. Currently, maize hybridization offers great advantages since from the first simple hybrids it is possible to evaluate important variables such as water productivity. The present work was carried out under field conditions in southern Sonora, in two sowing seasons: December 2022- May 2023 (SD 1) and April-August 2023 (SD 2). The research aimed to evaluate the effect of two sowing dates (SD) on phenology, water requirements, water productivity and grain yield. Three single white grain hybrids (L5 X L7; L1 X L2; L2 X L7) obtained from a dialelic design were evaluated. Phenophase occurrence time, irrigation time and interval, total water volume, evapotranspiration, grain yield and water productivity were the evaluated variables. The results showed that in SD 2 significantly reduced the time of occurrence of phenophases in all hybrids due to the effect of temperature. Irrigation time was significantly shorter in SD 2 compared to SD 1. Similarly, the irrigation interval decreased in SD 2 compared to SD 1 with a significant increase in the irrigation lamina. It was necessary to apply two more irrigations to achieve grain filling. Water productivity showed highly significant differences between hybrids and between sowing dates. The simple hybrid L5 X L7 showed better agronomic performance on both sowing dates, demonstrating tolerance to the increase in temperature on SD 2.