Maize Grain Research Articles

Safe Utilization Effect of Passivator on Mild to Moderate Cadmium Contaminated Farmland

In order to study the safe utilization of acid cadmium （Cd） contaminated soil， light and moderate Cd-contaminated farmland in Shangluo， Shaanxi Province was taken as the research object， and lime， biochar， and calcium magnesium phosphate fertilizer were applied. Through the wheat-maize rotation experiment， the safe utilization effect of different amounts of passivator on Cd-contaminated soil was explored， and the best ratio of passivator was selected. The results showed that： ① the soil quality could be improved to varying degrees by applying the passivator. ② After the application of amendments， the grain yield of wheat and maize increased to different degrees. ③ The lime 2 340 kg·hm-2 （C3） treatment had the best effect， which increased the soil pH of wheat and corn by 1.453 and 1.717 units， respectively， and reduced the available Cd content by 34.38% and 30.20%， respectively. ④ The application of biochar 1 800 kg·hm-2 （B2） treatment had the best effect on reducing the Cd contents in wheat roots， straws， and grains， which were significantly reduced by 53.60%， 38.86%， and 52.96%， respectively， compared with that in CK. The Cd content in wheat grains was reduced to 0.09 mg·kg-1， which was lower than the limit value of wheat Cd （0.1 mg·kg-1） specified in the "National food safety standard food pollutant limit" （GB 2762-2017）. The application of the biochar 1 260 kg·hm-2 （B1） treatment had the best comprehensive effect on reducing the Cd contents of maize roots， straws， and grains， which were significantly reduced by 43.74%， 53.20%， and 94.57%， respectively， compared with that in CK. The Cd content of maize grains was reduced to 0.001 9 mg·kg-1， which was far lower than the limit value of maize Cd （0.1 mg·kg-1） specified in the "National food safety standard food pollutant limit" （GB 2762-2017）. Therefore， under the conditions of the field experiment， considering the influence of various indexes， biochar had the best effect on farmland soil in the wheat-maize rotation area with mild to moderate Cd pollution.

Intercropped Maize and Cowpea Increased the Land Equivalent Ratio and Enhanced Crop Access to More Nitrogen and Phosphorus Compared to Cultivation as Sole Crops

Sub-Saharan African smallholder farmers face challenges due to limited access to commercial fertilizers, affecting food security. Exploring the benefits of intercropping is promising, but evaluating crop performance in specific agroecological contexts is crucial. This study in Vilankulo, Mozambique, conducted over two growth seasons (2018 and 2019), aimed to assess the benefits of intercropping maize (Zea mays L.) and cowpea (Vigna unguiculata L., Walp) (M+C) compared to maize (M) and cowpea (C) as sole crops. Key variables for comparison included dry matter yield (DMY), land equivalent ratio (LER), competitive ratio (CR), tissue nutrient concentration, nutrient recovery, and apparent N fixation (ANF). This study also examined the effects on cabbage (Brassica oleracea L.), cultivated as a succeeding crop, and soil properties. In 2018, maize plants were severely affected by drought and did not produce grain. This year, cowpea grain yields were 2.26 and 1.35 t ha−1 when grown as sole crop or intercropped. In 2019, maize grain yield was 6.75 t ha−1 when intercropped, compared to 5.52 t ha−1 as a sole crop. Cowpea grain yield was lower when intercropped (1.51 vs. 2.25 t ha−1). LER values exceeded 1 (1.91 and 1.53 for grain and straw in 2019), indicating improved performance in intercropping compared to sole crops. In 2019, CR was 1.96 for maize grain and 0.58 for cowpea grain, highlighting the higher competitiveness of maize over cowpea. Cowpea exhibited higher average leaf nitrogen (N) concentration (25.4 and 37.6 g kg−1 in 2018 and 2019, respectively) than maize (13.0 and 23.7 g kg−1), attributed to its leguminous nature with access to atmospheric N, benefiting the growth of maize in intercropping and cabbage cultivated as a succeeding crop. Cowpea also appears to have contributed to enhanced phosphorus (P) absorption, possibly due to access to sparingly soluble P forms. In 2019, ANF in M+C was 102.5 kg ha−1, over 4-fold higher than in C (25.0 g kg−1), suggesting maize accessed more N than could cowpea provide, possibly through association with endophytic diazotrophs commonly found in tropical grasses.

Genetic Analysis of Accumulation of Amylose and Resistant Starch in Subtropical Maize Hybrids

AbstractAmylose and resistant starch (RS) possess numerous industrial applications and health benefits. However, maize grains possess low amylose (<35%) and RS (<5%). To date, no information is available on the genetic variability of amylose and RS in subtropical maize. Here, 21 hybrids developed using half‐diallel mating design are evaluated for starch parameters at three locations. Analysis of variance (ANOVA) revealed a minor contribution for environments for amylose and RS. Amylose (22.2%–49.1%) and RS (1.02%–23.9%) showed wide variation among the hybrids. The experimental hybrids possessed significantly higher amylose (38.1%) and RS (20.9%) over the check hybrids (amylose: 29.1%, RS: 2.3%). PUSA‐AML‐H12, PUSA‐AML‐H18, and PUSA‐AML‐H16 are observed to be the most promising hybrids. Amylose and RS are positively correlated (r = 0.45), while total starch (TS) is negatively correlated with RS (r = −0.53). PMI‐AML‐147, PMI‐AML‐149, and PMI‐AML‐146 are the best general combiners for amylose and RS. Pusa‐AML‐H1, Pusa‐AML‐H12, and Pusa‐AML‐H5 emerged as the best specific combiners for amylose and RS. Both additive and nonadditive variances are important for amylose and RS. This is the first study of amylose and RS in a subtropical maize background, which could be significant in improving amylose and RS.

Crop residues integration with nitrogen rates reduces yield-scaled nitrous oxide emissions and improves maize yield and soil quality

ABSTRACT Maize production requires a large amount of nitrogen (N). However, a greater part of the N used gets lost to the environment as reactive forms including nitrous oxide (N2O). N2O emissions and associated soil-related factors were measured in a maize (Zea mays L.) field in the 5th crop after initiation of the experiment in an annual maize-rice sequence. The treatments comprised two levels of crop residues (no residue, NR vs. 30 cm residue, CR) with four levels of N fertilizers (control; farmers’ practice, FP; national recommended dose, RD, and 125% of RD, 1.25 RD). Mean and cumulative N2O emissions increased with N rate coupled with either residue level. The CR coupled with 1.25 RD had 10% higher N2O emissions than the same rate as NR. In contrast, yield-scaled N2O emissions were equal in 1.25 RD coupled with either residue level. However, higher N2O emissions in CR than in NR can be offset by the corresponding improvement in soil elemental quality, e.g. soil organic carbon, total N, P, K and S. The N2O emission factor, ranged from 0.99 to 1.34, and was higher in CR coupled with 1.25 RD than in any other combination suggesting that optimization of N rate is one of the best options to reduce N2O emissions. Maize grain yield was higher in RD and 1.25 RD than in the farmers’ practice where the former two were similar to each other. Step-wise multiple regression showed that N application rate, soil organic carbon, total N and pH are the dominant factors controlling N2O emissions. Our results suggest that maize production can benefit from residue retention with the current N rate (RD) for better yield, soil quality and N2O mitigation.

Exogenous abscisic acid (ABA) improves the filling process of maize grains at different ear positions by promoting starch accumulation and regulating hormone levels under high planting density

BackgroundHigher planting densities typically cause a decline in grain weight, limiting the potential for high maize yield. Additionally, variations in grain filling occur at different positions within the maize ear. Abscisic acid (ABA) is important for grain filling and regulates grain weight. However, the effects of exogenous ABA on the filling process of maize grains at different ear positions under high planting density are poorly understood. In this study, two summer maize hybrids (DengHai605 (DH605) and ZhengDan958 (ZD958)) commonly grown in China were used to examine the effects of ABA application during the flowering stage on grain filling properties, starch accumulation, starch biosynthesis associated enzyme activities, and hormone levels of maize grain (including inferior grain (IG) and superior grain (SG)) under high planting density.ResultsOur results showed that exogenous ABA significantly increased maize yield, primarily owing to a higher grain weight resulting from an accelerated grain filling rate relative to the control. There was no significant difference in yield between DH605 and ZD958 in the control and ABA treatments. Moreover, applying ABA promoted starch accumulation by raising the activities of sucrose synthase, ADP-glucose pyrophosphorylase, granule-bound starch synthases, soluble starch synthase, and starch branching enzyme in grains. It also increased the levels of zeatin riboside, indole-3-acetic acid, and ABA and decreased the level of gibberellin in grains, resulting in more efficient grain filling. Notably, IG exhibited a less efficient filling process compared to SG, probably due to lower starch biosynthesis associated enzyme activities and an imbalance in hormone contents. Nevertheless, IG displayed greater sensitivity to exogenous ABA than SG, suggesting that appropriate cultural measures to improve IG filling may be a viable strategy to further increase maize yield.ConclusionsAccording to our results, spraying exogenous ABA could effectively improve grain filling properties, accelerate starch accumulation by increasing relevant enzyme activities, and regulate hormone levels in grains, resulting in higher grain weight and yield of maize under high planting density. Our findings offer more evidence for using exogenous hormones to improve maize yield under high planting density.

Effects of Tillage Practices on the Growth and Yield of Maize, in the Guinea Savannah Ecological Zone of Ghana

Abstract: A field study was conducted to investigate the influence of conventional tillage (CVT) and conservation tillage (CST) on various aspects of maize yield parameters and grain yield, using the Wagdaata maize variety. The study was conducted at the experimental farm of Tamale Technical University, located at Northern region, Tamale, Sagnarigu municipality in the Guinea savannah ecological zone of Ghana in 2023 cropping season. A randomised complete block design was used with three replicates. The treatments consisted of two tillage practices: conventional tillage (CVT) and conservation tillage (CST) and a control. The CVT involved plowing the soil to a depth of 15cm using a tractor plough with disk to plow. The CST involved use of hoe to make ridges and the control was direct seeding without loosen the soil. Plant height was evaluated every two weeks by measuring the height of maize to the base of the apex leaf. Other data collected were: maize leaf area. Cob characteristics including ear height, cob weight with husk, fresh cob weight, and dry cob weight, number of cobs per hectare and number of kernels per cob, 1000 seed weight and grain yields. The present study revealed that plant height, maize leaf area and shoot dry weight increased in the ridges than the other tillage practices. Cob characteristics such as ear height, cob weight with husk, fresh cob weight, and dry cob weight, number of cobs per hectare and number of kernels per cob, 1000 seed weight and grain yields was also optimum with the ridges as a against the other tillage practices. The study showed increased grain yield by 66% in the ridge tillage (2,389 kg/ha) over the plough tillage (1,436 kg/ha). The study provides comprehensive insights into the impact of tillage practices on various aspects of maize growth and yield, with ridge tillage emerging as a favorable practice for optimizing maize plant development and overall productivity in the Guinea savannah ecological zone of Ghana.

The Contribution of Climate-Smart Agriculture to Reducing Climate-Related Risks to Rain-Fed Maize Production: Insights from Tanzania’s Semi-Arid and Sub-Humid Regions

Adaptation responses of rain-fed smallholder farming systems to climate change and variability have become more unpredictable. Semi-arid and sub-humid regions are most affected by knowledge gaps on climate change adaptation strategies. Climate-smart agriculture (CSA) practices are crucial because they ensure predictable and effective adaptation responses that reduce crop failures. To determine potential new strategies for farm-level climate change adaptation, this study examined the implications of three CSA practices on rain-fed maize production: crop diversification, intercropping, and planting date adjustment. Plot-level data were obtained from the Tanzania National Panel Survey (TNPS) throughout waves 1 (2008/2009) and 2 (2010/2011). The consistency of the adaptation responses was evaluated using test-retest reliability. The findings showed that intercropping and splitting plots to plant crops other than maize was an analogue for crop diversification and reduced variability of maize grain yields. The panel linear regression model revealed that the yields of maize grains were positively correlated with intercropping and crop diversification (plot division). Moreover, the results of the meta-analysis showed that intercropping, crop diversification, and planting date adjustments could greatly increase smallholder rain-fed maize farmers’ resistance to the effects of climate variability and change. The government and non-governmentalorganizations should be encouraged to provide funding for agricultural extension education, which is a major factor in the implementation of CSA techniques.

Enhancing nitrogen use efficiency and yield of maize (Zea mays L.) through Ammonia volatilization mitigation and nitrogen management approaches

Management of nitrogen (N) fertilizer is a critical factor that can improve maize (Zea mays L.) production. On the other hand, high volatilization losses of N also pollute the air. A field experiment was established using a silt clay soil to examine the effect of sulfur-coated urea and sulfur from gypsum on ammonia (NH3) emission, N use efficiency (NUE), and the productivity of maize crop under alkaline calcareous soil. The experimental design was a randomized complete block (RCBD) with seven treatments in three replicates: control with no N, urea150 alone (150 kg N ha−1), urea200 alone (200 kg N ha−1), urea150 + S (60 kg ha−1 S from gypsum), urea200 + S, SCU150 (sulfur-coated urea) and SCU200. The results showed that the urea150 + S and urea200 + S significantly reduced the total NH3 by (58 and 42%) as compared with the sole application urea200. The NH3 emission reduced further in the treatment with SCU150 and SCU200 by 74 and 65%, respectively, compared to the treatment with urea200. The maize plant biomass, grain yield, and total N uptake enhanced by 5–14%, 4–17%, and 7–13, respectively, in the treatments with urea150 + s and urea200 + S, relative to the treatment with urea200 alone. Biomass, grain yield, and total N uptake further increased significantly by 22–30%, 25–28%, and 26–31%, respectively, in the treatments with SCU150 and SCU200, relative to the treatment with urea200 alone. The applications of SCU150 enhanced the nitrogen use efficiency (NUE) by (72%) and SCU200 by (62%) respectively, compared with the sole application of urea200 alone. In conclusion, applying S-coated urea at a lower rate of 150 kg N ha−1 compared with a higher rate of 200 kg N ha−1 may be an effective way to reduce N fertilizer application rate and mitigate NH3 emission, improve NUE, and increase maize yield. More investigations are suggested under different soil textures and climatic conditions to declare S-coated urea at 150 kg N ha−1 as the best application rate for maize to enhance maize growth and yield.

Above-and below-ground feedback loop of maize is jointly enhanced by plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi in drier soil

Drought is a potent abiotic stressor that arrests crop growth, significantly affecting crop health and yields. The arbuscular mycorrhizal fungi (AMF), and plant growth-promoting rhizobacteria (PGPR) can offer to protect plants from stressful environments through improving water, and nutrient use efficiency by strengthening plant root structure and harnessing favorable rhizosphere environments. When Acaulospora laevis (AMF) and Bacillus subtilus (PGPR) are introduced in combination, enhanced root growth and beneficial microbial colonization can mitigate drought stress. To assess this potential, a pot experiment was done with maize (Zea mays L.) to explore the effects of A. laevis and B. subtilus under different water levels (well-watered = 80 %; moderate water stress = 55 %; and severe water stress = 35 %) on maize yield, soil microbial activities, nutrients contents, root, and leaf functioning. Plants exposed to severe drought stress hampered their root and leaf functioning, and reduced grain yield compared with control plants. Combined use of AMF and PGPR increased root colonization (104.6 %–113.2 %) and microbial biomass carbon (36.38 %–40.23 %) under moderate to severe drought conditions over control. Higher root colonization was strongly linked with elevated ACC (aminocyclopropane-1-carboxylic acid) production, subsequently enhancing water use efficiency (21.62 %–12.77 %), root hydraulic conductivity (1.9 %–1.4 %) and root nutrient uptake under moderate to severe drought conditions. Enhanced nutrient uptake further promoted leaf photosynthetic rate by 27.3 %–29.8 % under moderate and severe drought stress. Improving leaf and root physiological functioning enhanced maize grain yield under stressful environments. Furthermore, co-inoculation with AMF-PGPR reduced cellular damage by lowering oxidative enzyme levels and increasing antioxidative enzyme activities, improving plant performance and grain yield under stressful environments. Conclusively, the synergistic interaction of AMF with PGPR ensured plant stress tolerance by reducing cellular injury, facilitating root-leaf functioning, enhancing nutrient-water-use-efficiencies, and increasing yield under drought stress.

INCIDENCE OF STORAGE FUNGI ACCORDING TO TOPDRESSING NITROGEN AND MAIZE VARIETIES

Maize is the main cereal grown in Brazil and is used mainly for animal feed and food consumption of its derivates. Under favorable environmental conditions, toxigenic fungi such as Fusarium, Aspergillus, and Penicillium spp. could produce mycotoxins in maize grain during plant growth or storage. This study aimed to evaluate the incidence of toxigenic fungi and its relationship with the grain weight of maize varieties grown under high and low topdressing nitrogen. The first factor consisted of 11 open-pollinated varieties, and the second factor of two topdressing nitrogen rates (60 and 180 kg ha-1). After harvesting the experimental units, the following variables were evaluated: 100-grain weight (HGW) and incidence of A. flavus, Penicillium spp., and Fusarium spp. There were differences (p<0.05) among maize varieties for all evaluated variables. There was a significant interaction between varieties and nitrogen for the percentage of seeds infected by A. flavus, Fusarium spp., and HGW. The incidence of fungi and HGW of maize depends on the variety and the topdressing nitrogen used.

Genetic Variability of Tocol Content in a Genebank Collection of Temperate Maize Inbred Lines from Southeastern Europe

Maize is considered a promising candidate for biofortification through breeding, given its widespread cultivation and significance as a food crop. This cost-effective and sustainable approach could be used to increase the content of different tocol compounds, i.e., vitamin E, in maize grain due to the well-documented genetic variability. In the present study, an evaluation of the content of nine different tocol traits was performed in a genebank collection of 88 inbred lines of temperate maize grown at two locations in Croatia in 2019. A large genotypic variability within the studied material was observed for α-tocopherol, γ-tocopherol, δ-tocopherol, total tocopherols, α-/γ-tocopherol ratio, α-tocotrienol, γ-tocotrienol, total tocotrienols and total tocols with corresponding coefficients of variation of 52, 61, 51, 45, 106, 24, 54, 33 and 38%, respectively. Heritability estimates ranged from 0.66 for α-tocotrienol to 0.95 for δ-tocopherol. The content of α-tocopherol, which has the highest vitamin E activity and is therefore most interesting for selection, was not significantly correlated with either grain color or grain type. Comparison of the effects of simulated selection with an intensity of 20% on increased α-tocopherol content using the two selection criteria, absolute α-tocopherol content and α-/γ-tocopherol ratio, showed that the highest absolute α-tocopherol content was a better selection criterion. Indeed, simulated selection based on the absolute α-tocopherol content resulted in a 64% increase in this compound without significantly affecting the total tocopherols, the total tocotrienols, and the α-/γ-tocopherol ratio.

Using olive and apple pomaces for fattening pig diets: Environmental impacts under an attributional and consequential perspective

The livestock sector plays an essential role in anthropogenic greenhouse gas emissions, where fodder crop production has been largely identified as the main contributor to their environmental impact. This research evaluates the attributional environmental impacts of introducing food industry subproducts such as apple and olive pomaces to reduce the proportion of maize grain in the formulation of diets for fattening pigs, according to four alternatives, including the current diet with 69% maize. For this, the life cycle assessment (LCA) methodology has been used to determine the hotspots associated to these changes, considering a cradle-to-gate approach and two functional units: 1 kg of feed diet (FU1) and 1 kg of weight gain (FU2). Furthermore, the potential environmental consequences of using these subproducts for pig diet have also been considered with a consequential LCA methodology. The results show that the best diet was the one containing about 33% maize and 43% subproducts for all categories analysed. In addition, the allocation method used to assign subproduct loads, including mass, economic, and zero-burdens allocation, is crucial to validate the assumptions and recommendations for this strategy. The consequential LCA results suggest that this strategy could involve both positive and negative impacts (considered as environmental credits), depending on the substitutes for the avoided maize stover and the potential displaced bioproducts that could be obtained from these subproducts, mainly for bioenergy production.

Timing is everything: how planting period shapes nutritional quality, mycobiota characteristics, and mycotoxin contamination in maize (Zea mays) grains

Timing is everything: how planting period shapes nutritional quality, mycobiota characteristics, and mycotoxin contamination in maize (Zea mays) grains

Influence of different population densities of Bambara groundnut intercrop and weeding frequency on maize (<i>Zea mays</i> L.) performance

Effective weed management is essential for enhanced productivity of maize. A two-year field experiment was carried out at the Department of Crop Science Demonstration Farm, University of Calabar, Calabar, Nigeria (4.5-5.20 N, 8.0-8.30 E), in the 2019 and 2020 early planting seasons, to evaluate the influence of three population densities of Bambara groundnut [166,666 plants per hectare(B1), 100,000 plants per hectare (B2), 71,428 plants per hectare (B3)] and four hand weeding frequencies [weedy check (WC), one hand weeding (1HW), two hand weedings (2HW) and a weed free check (WFC)] on the performance of maize. The experiment consisted of three replications fitted into a Randomized Complete Block Design (RCBD). Data gathered on maize vegetative and yield characteristics were analysed using analysis of variance (ANOVA) procedures for RCBD (GenStat® statistical package, version 8.1). Significantly different means were compared at 5 % probability level using the Duncan’s New Multiple Range Test (DNMRT). From the results, maize growth and yield performance were significantly (P<0.05) affected by Bambara groundnut populations and the frequency of weeding. Leaving weeds unchecked all through the cultivation season hampered the vegetative and yield performance of maize, resulting in 47.54 % reduction in maize grain yield, compared with the weeded plots. Conclusively, intercropping maize with Bambara groundnut at 71,428 plants per hectare integrated with two hand weedings at 4 and 8 weeks after sowing (WAS), which optimized maize grain yield (3.87 t/ha on the two-year average) is recommended for farmers in the Calabar humid area and its environs.

Can straw recycling achieve sustainable agriculture at the smallholder level? A case in a semi-arid region

Diversified straw recycling practices are essential to achieve sustainable agriculture at the smallholder level. This study comprehensively evaluated the sustainability of two straw recycling models, agro-pastoral-biogas (CCBS) and carbonization (CBBS). The findings demonstrated that the economic indicators (such as spring maize yield and net economic benefits) accounted for a larger proportion of the total score in the CCBS model, indicating that the model is more sustainable for promoting smallholder economic income, while the CBBS model performed even better in carbon sequestration and emission reductions. These results were attributed to the more notable increase in spring maize productivity and the addition of two production units, fattening and biogas digester. However, the sustainability of the CCBS model declined as the straw recycling chain lengthened; the CBBS model had the highest sustainability index. Specifically, maize grain yield and SOC storage increased by 3.86%–11.7% and 11.66%–36.07%, respectively, and soil GHG emissions increased by 20.57% and decreased by 59.9%, respectively, for both models. Despite the substantial economic or environmental benefits, neither model can achieve the win-win goal of sustainability. We conservatively recommend the CCBS model and suggest more specialized smallholder production, but call for more interventions to optimize the CCBS model, as it encompasses multiple development objectives, such as combining planting and breeding, energy substitution, and carbon sequestration-emission reduction, which is more in line with the aspirations of smallholders and other groups.

Comparison of the AquaCrop and CERES‐Maize models for simulating maize phenology, grain yield, evapotranspiration and water productivity under different irrigation and nitrogen levels

AbstractThe CERES‐Maize and AquaCrop models were evaluated for their performance in simulating maize (Zea mays L.) phenology, evapotranspiration (ETc), grain yield and crop water productivity (CWP). Model input data for calibration, validation and simulations were obtained from field experiments conducted from 2011 to 2014 that imposed three different irrigation levels (full irrigation treatment [FIT], limited irrigation treatment [75% FIT] and rainfed control) and five nitrogen (N) management treatments. Both models performed well in simulating the maize phenological stages, with simulated values being within 1–4 days of measured values for both models. Both models simulated grain yield well during the calibration with a normalized root mean squared error (RMSEn) of 5% (0.6 t ha⁻1) for CERES‐Maize and 8% (0.80 t ha⁻1) for AquaCrop. The model error for ETc varied from −2 to +14% for CERES‐Maize and ranged from −3 to +11% for AquaCrop. High N levels resulted in higher accuracy in predicting ETc. The AquaCrop model performed better than CERES‐Maize in simulating irrigated crop production under different N levels under rainfed conditions. The performance of both models for rainfed systems was poorer than their performance in irrigated systems, indicating that both models need further improvements in simulating rainfed maize production systems.

Reduction in rancidity development in fortified whole‐grain maize meal by hot‐air drying of the grain

AbstractBackground and ObjectiveMaize is the major staple in sub‐Saharan Africa. Whole‐grain maize meal (WGMM) is highly susceptible to rancidity development. This work investigated whether rancidity development in micronutrient‐fortified WGMM is retarded by drying the grain of safe moisture content to below this level using a commercial hot‐air grain dryer before milling.FindingsFat acidity (hydrolytic rancidity measure) of WGMM from maize dried to 11.6% moisture and stored for 47 days at 40°C was only 61% of meal from the undried grain control (13.3% moisture). Peroxide value (oxidative rancidity measure) was only 53%. With the exception of riboflavin, there was no reduction in fortificant micronutrients during meal storage. Descriptive sensory evaluation indicated greater similarity to the control for stored maize meal and its stiff porridge from dried maize than for meal and porridge from undried maize.ConclusionsDrying maize grain to 11.6% moisture substantially retards rancidity development in fortified WGMM development, probably by inactivating the grain's lipase and oxidative enzymes, providing a shelf life of at least 20 weeks at 25°C.Significance and NoveltyThis simple process to extend the shelf life of whole‐grain maize meal is implementable by any mill with access to a hot‐air grain dryer.

Characterization of Aspergillus section Flavi associated with stored grains

Increased frequencies of Aspergillus section Flavi and aflatoxins in cereal grains have been seen in recent years due to changes in climate circumstances, such as high temperatures and drought. To assess the microbiological risks of contamination, it is critical to have a reliable and accurate means of identifying the fungi. The main goal of this study was to characterize Aspergillus species from section Flavi obtained from twenty-three samples of barley and maize grains, gathered from different markets in Qena, Egypt, using morphological and molecular techniques. Twenty-three isolates were chosen, one isolate from each sample; they were identified as A. aflatoxiformans (4 isolates), A. flavus (18), and A. parasiticus (1). The existence of four aflatoxin biosynthesis genes was also investigated in relation to the strains’ ability to produce total aflatoxins and aflatoxin B1, focusing on the regulatory gene aflR and the structural genes aflD and aflM. All strains producing aflatoxins were linked to the presence of aflR1 and/or aflR2, except two isolates that exhibited aflatoxins but from which aflR1 or aflR2 were not detected, which may be due to one or more missing or unstudied additional genes involved in aflatoxin production. AflD and aflM genes were amplified by 10 and 9 isolates, respectively. Five samples of barley and maize were contaminated by aflatoxins. Fifteen isolates were positive for producing total aflatoxins in the range of 0.1–240 ppm. Antagonistic activity of Trichoderma viride against A. flavus (F5) was assessed at 31.3%. Trichoderma reduced total aflatoxins in all treated seeds, particularly those subjected to Trichoderma formulation.

Intercropping of Pteris vittata and maize on multimetal contaminated soil can achieve remediation and safe agricultural production

Soil contamination by multimetals is widespread. Hyperaccumulator–crop intercropping has been confirmed to be an effective method for arsenic (As)- or cadmium (Cd)-contaminated soil that can achieve soil cleanup and agricultural production. However, the influencing factors and response of hyperaccumulator–crop intercropping to multimetal-contaminated soil are still unclear. In this study, intercropping of the As hyperaccumulator Pteris vittata and maize was conducted on two typical types of multimetal-contaminated soil, namely, Soil A contaminated by As, Cd, and lead (Pb) and Soil B contaminated by As, Cd, and chromium (Cr). Intercropping reduced As, Cd, and Pb in the maize grains by 60 %, 66.7 %, and 20.4 %, respectively. The concentrations of As, Cd, Pb, and Cr in P. vittata increased by 314 %, 300 %, 447.3 %, and 232.6 %, respectively, relative to their concentrations in the monoculture plants. Two soils with different levels of contamination showed that higher heavy metal content might diminish the ability of intercropping to reduce soil heavy metal risk. No notable difference in soil microbial diversity was found between the intercropped and monocultured plants. The composition of microbial communities of intercropping groups were more similar to those of monoculture P. vittata on two different soils (Soils A and B). An imbalance between the amount of As taken up by the plants and the reduction in As in the soil was observed, and this imbalance may be related to watering, As leaching, and heterogeneity of soil As distribution. Reducing the risk resulting from As leaching and enhancing the efficiency of phytoextraction should be emphasized in remediation practices.

The role of zinc fertilization and its interaction with nitrogen and phosphorus starter fertilization on early maize development and grain yield

The early planting of maize in temperate growing areas leads to yield and quality benefits, although a low soil temperature can affect the early nutrient uptake and delay plant development. Not only can the nitrogen (N) and phosphorus (P) uptake be limited, but that of zinc (Zn) can also be affected. Moreover, the application of N and P at early growth stages can result in an enhancement of maize growth. Two field experiment were carried out in North Italy during the 2012–14 period to: i) evaluate the most effective Zn application strategy by comparing seed, soil and foliar applications with an untreated control; ii) investigate the role of a Zn seed treatment on the early development and yield of maize grown in three different types of soils. The effect of Zn application was compared, in both experiments, to starter NP fertilization in bands at planting, according to a full factorial design. Zn fertilization significantly enhanced the early vigor and yield of the maize, although the effects were less pronounced than those of the NP fertilizer. Among the Zn fertilization strategies, maize growth was quicker for the seed and soil applications than for the foliar application or the untreated control. The former application significantly increased the plant height at stem elongation (+32%), shortened the planting-flowering period by 1 day, and increased the grain yield by 4%. Overall, the application of NP starter fertilizer shortened the planting-flowering period by 4.5 days and increased the yield by 10%, compared to the unfertilized control. In the second experiment, higher plant vigor indices were detected in all the soils for the NP starter fertilization (+22–27%) and for the Zn seed treatment (+3–9%) than in the controls. The NP starter fertilization reduced the grain moisture at harvest by 2.3% and increased grain yield by 14%, while the Zn treatment significantly increased the kernel weight but did not affect the grain yield or the moisture content. The interaction between the NP fertilization and the Zn treatment was never significant. Thus, the positive effect of Zn on the early vigor was an additional benefit to that produced by the starter NP fertilization. The study demonstrated that a Zn application at planting, with both a seed dressing and a soil treatment, significantly enhanced the early growth of different maize hybrids, in different growing seasons and soils, although the use of a NP starter fertilization led to more consistent agronomic benefits. Furthermore, the combination of NP and Zn starter fertilization resulted in a further advantage for all the considered production situations.