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【Objective】Establishing a universal PCR detection system would address the issue of inconsistent amplification systems and reaction conditions of different events, thereby enhancing the efficiency of event detection.【Method】In this study, we analyzed and compared the differences in amplification systems and reaction conditions of qualitative and quantitative PCR detection methods for the specificity of transgenic material events. The most widely used PCR systems and conditions parameters were selected as unified parameters to validate the PCR qualitative detection methods for different maize events in the laboratory.【Result】General PCR amplification system: Total volume 25.0 μL, 25 mmol/L MgCl2 solution 1.5 μL, 2.5 mmol/L dNTPs mixed solution 2.0 μL, final concentration of upstream and downstream primer 0.4 μmol/L, Taq DNA polymerase 0.025 U/μL, 25 mg/L DNA template 2.0 μL, LOD 0.1%. Reaction conditions: Denaturation at 94℃ for 5 min, 35 cycles of denaturation at 94℃ for 30 s, annealing at 58℃ for 30 s, extension at 72℃ for 30 s, and final extension at 72℃ for 7 min. Universal real-time fluorescent qualitative PCR amplification system: Total volume 20.0 μL, 25 mmol/L MgCl2 solution 2.0 μL, dNTPs mixed solution (2.5 mmol/L each) 1.6 μL, final concentration of upstream and downstream primers and probe 0.4 μmol/L, Taq DNA polymerase 0.04 U/μL, 25 mg/L DNA template 2.5 μL, LOD 0.1%. Reaction conditions: denaturation at 95℃ for 5 min; 95℃ denaturation 15 s, 60℃ annealing extension 60 s, 40 cycles.【Conclusion】This system and its associated amplification system and reaction conditions can be used to detect different event materials. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Maize (Zea mays L.) is one of the most versatile multi-purpose crop used as feed and food crop beside other no-food uses. During 2023 year a field experiment in a randomized complete block design with three replications and fourteen treatments was carried out in the Agricultural and Research Station Caracal with the aim of evaluation of weed control in maize, using new generation herbicides. The treatments were composed of isolated and associated herbicides and all were considered selective in maize via pre-emergence (PRE) and post-emergence (POST) applications. The efficacy evaluation was done at 7, 14, 21 and 28 days since each treatment targeting CHEAL, HIBTR, DATST, POLSS, CONAR, ECHCG, SETVI, SORHA, CYNDA, DIGSA, MATSS, AMBEL, GALPA, POROL, SOLNI. Results revealed that, among the herbicidal treatments, the best efficacy was recorded by SAE 053 H/01 + Baracuda doze p.c. 1.2 + 0.5; SAE 053 H/01 + Nico 40 OD doze p.c. 1.2 + 0.5; SAE 053 H/01 + Baracuda +Nico 40 OD doze p.c. 1.2 + 0.5 + 0.5. [ABSTRACT FROM AUTHOR]

Genotypic studies using molecular markers, such as genomic prediction (GP), have been implemented in maize (Zea mays L.) breeding, leading to a better understanding of significant traits. Pythium root and stalk rot (RSR) resistance is an important trait in maize bred in Japan. The study aims to (1) develop a GP model for Pythium RSR resistance in maize bred within the Japanese public sector and (2) utilize GP to analyze untested maize germplasms for Pythium RSR resistance via a combined training set derived from different heterotic groups (dent and flint). Through 1,000 repetitions of sampling and five-fold cross-validation, a high average prediction accuracy (r = 0.695, 95% confidence interval: 0.682-0.708) was achieved across populations. Prediction accuracy improved as the number of markers increased, but it eventually reached a plateau that exceeded 1,000 markers. The population component and linkage disequilibrium between markers confirmed previous reports. These findings show the feasibility of GP, even with a small population (N = 41) and marker size (approximately 1,000). Several old inbred lines were identified with lower predicted RSR scores, indicating their potential as breeding materials. This is the first report on the prediction of maize Pythium RSR resistance using GP and emphasizes new possibilities for addressing Pythium RSR resistance in maize breeding. [ABSTRACT FROM AUTHOR]

Copyright of Caspian Journal of Environmental Sciences is the property of University of Guilan & Association of Universities of the Caspian Region States and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

DNA methylation is an important epigenetic regulatory mechanism, it regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factor(s) to DNA. In this study, a novel methyltransferase 2a gene (Zmet2a) was cloned in maize and identified by polymerase chain reaction-base (PCR-base) using a bioinformatics strategy. The Zmet2a cDNA sequence is 2739 bp long and translates to 912 amino acid peptides. The Zmet2a protein revealed that it contains BAH and CHROMO structural domains, is a non-transmembrane protein that is hydrophilically unstable, and has no signal peptide structure. Meanwhile, we verified the biological roles of Zmet2a using transgenic Arabidopsis overexpressing Zmet2a and Zmet2a -knockout maize. Transgenic Zmet2a Arabidopsis thaliana showed highly significant advancement in flowering time, and Zmet2a -knockout maize showed advancement in flowering time, with significant changes in several traits. Altogether, these report the role of Zmet2a in the regulation of flowering time, which will lay a foundation for revealing the biological function and epigenetic regulation mechanism of Zmet2a in the growth, development and flowering of maize. Supplementary Material Supplementary Material File [ABSTRACT FROM AUTHOR]

Deep placement of controlled-release urea is an effective fertiliser management strategy for improving the maize productivity, but it is not clear whether and how controlled-release urea depth affects the stem and root lodging of spring maize. Two consecutive years of field experiments were conducted to elucidate stem and root lodging properties and their relationship between grain yield and lodging behaviours under various controlled-release urea placement depths. Results depicted that compared to broadcast nitrogen treatment (D0), deep controlled-release urea significantly decreased the stem lodging rate by 34.7-80.4%, which contributed to improving the mechanical characteristics of the internode by optimising the internode diameter and dry matter in the third basal internode as well as higher lignin content. In addition, due to a greater and deeper root system (root dry weight, root surface area, root length and root width) as well as larger angle, diameter, and tension of aerial root that significantly decreased root lodging rate (37.0-88.4%). Furthermore, deep placement of controlled-release urea significantly increased the 100-grain weight, grain number and harvested index by constructing a deeper and larger root system, which significantly improved maize grain yield by 14.2-38.5%, and the nitrogen use efficiency increased by 4.8-10.7%. The highest grain yield, nitrogen use efficiency and lowest lodging rate occurred in controlled-release urea placement depths of 15 cm. Hence, our study suggests that controlled-release urea placement depths of 15 cm were an efficient nitrogen fertiliser management strategy to improve crop productivity as well as lodging resistance in spring maize. [ABSTRACT FROM AUTHOR]

The replacement of Caatinga by extensive agriculture has led to soil degradation in maize (Zea mays L.) growing areas. The objective of this study was to evaluate the effects of soil correction in association with Azospirillum brasiliense to replace nitrogen (N) fertilizer on the vegetative growth of two maize genotypes cultivated on degraded soil. The soil was collected in an area undergoing desertification in Irauçuba, Ceará state, Brazil. A 2x2x5 factorial experiment was carried out in blocks: two soil fertility levels (corrected and uncorrected soil in terms of fertility), two maize genotypes (BRS Caimbé and BRS Gorutuba), and five nitrogen sources (control, inoculation with A. brasilense, inoculation with A. brasilense + 50 kg ha-1 of N, 50 kg ha-1 of N, and 100 kg ha-1 of N). BRS Gorutuba genotype showed greater adaptability to the growing conditions evaluated. However, macronutrient concentration did not affect maize dry matter yield. The response of maize inoculated with A. brasiliense suggests the inoculation efficacy, supported by the N accumulation and the effect on plant growth. The dry matter yield in A. brasilense inoculated plants was equivalent to using N fertilizer. Therefore, the inoculation of BRS Gorutuba maize grown on degraded soil with A. brasilense is a promising alternative for farmers in semi-arid regions. [ABSTRACT FROM AUTHOR]

The goal of this study is to establish the impact of tillage (reversible to a depth of 25-28 cm and irreversible to a depth of 25-28, 15-18 and 5-8 cm) and the fertilizing products such as LEANUM and VITAMIN O7 (liquid and powdered, respectively) for growing Hemingway and Harmonium hybrids with FAO 280 and 380 on the leaf area duration (LAD) and the concentration of chlorophyll a and b. The leaf area duration was measured by the method of M. I. Orlovskyi and calculated using the formula. The content of chlorophyll a and b in maize leaves was determined using the ULAB 102 Spectrophotometer. In general, the effect of biofertilizer treatment on the leaf can be noted by increasing the leaf area duration. Thus, for Harmonium, with any variant of tillage, the leaf area duration increased on the variants of foliar treatment. And on irreversible tillage for three years, an increase in the leaf area duration was noted with the use of pre-sowing inoculation with the studied fertilizing products, one treatment with LEANUM foliar, and a combined treatment with LEANUM + 1 LEANUM. It is worth noting that disking to a depth of 5-8 cm only led to a decrease in the leaf area duration during the cultivation of Harmonium. However, when growing Hemingway, almost all variants had a positive effect on the leaf area duration, with the exception of inoculation (when using both fertilizing products). An interesting fact is that in most cases, an increase in the leaf area duration led to a decrease in the concentration of chlorophyll a, but did not lead to a decrease in the total concentration of chlorophylls a and b, due to an increase in the concentration of chlorophyll b. It should be noted that biofertilizer treatment and tillage significantly affected the concentration of chlorophyll a and chlorophylls a and b, but chlorophyll b was not affected by tillage. When growing Hemingway, neither biologics nor tillage had any effect, while other pigments had a significant effect. [ABSTRACT FROM AUTHOR]

This study aimed to ascertain the differences in the nutritional composition of maize grains by analysing their lipid, protein, fatty acid, triacylglycerol, and sugar content before and after undergoing an accelerated aging (AA) test. Additionally, phytochemicals (total pigments, phenolics and flavonoids), as well as antioxidant potential of maize grains were evaluated through ABTS•+ scavenging capacity and ferric reducing power (FRP) assays. Maize was cultivated in Serbia during the 2017 season, employing two growing systems (conventional and organic). Although minimal differences were observed in protein and lipid content, the grains proved to be an excellent source of polyunsaturated fatty acids and triacylglycerols with ECN44 fraction being predominant. The total soluble sugar content was low, while starch content was significantly higher. HPLC analysis confirmed a considerably higher prevalence of non-reducing disaccharides compared to reducing disaccharides. Maize grains emerged as a substantial source of chlorophyll a (0.53-4.38 µg/g DW), phenolics (1498.9-1931.3 mg FAE/kg DW), and flavonoids (85.7-381.9 mg QE/kg DW). All tested extracts exhibited satisfactory abilities to neutralize free ABTS•+. The FRP assay revealed a significantly higher ability to reduce Fe3+-ions in conventionally produced grains. According to the Blunt-Altman test, all analysed parameters showed considerable similarity, except for chlorophylls a and b. Principal component analysis (PCA) revealed that grains exposed to the AA test were mainly separated based on chlorophyll a, C20:0, C18:1n-9, MUFA, carotenoids, lipids content. Conversely, conventional untreated grains were primarily distinguished by their pentose, hexose and chlorophyll b content, while in the case of organic samples, disaccharides (both reducing and non-reducing) and soluble sugars were the main differentiating factors. The present preliminary study can serve as foundational research for future investigations aimed at comprehending alterations in nutrients and phytochemicals induced by accelerated aging tests. However, it should be supplemented and expanded upon by subsequent studies in the future. [ABSTRACT FROM AUTHOR]

The amalgamation of nanotechnology and biotechnology holds immense potential for developing innovative and essential products beneficial to mankind. Nanoparticles, particularly iron nanoparticles, exhibit the capacity to enhance plant growth and yield in various crops. Rather than employing nanomaterials alone, combining them with beneficial microorganisms can offer a more effective approach to promoting plant growth and yield. Piriformospora indica, a versatile endophytic fungus serves as a biofertilizer, bioregulator, stimulant, and biocontrol agent upon colonizing plant roots. The present study focuses on the synthesis and characterization of iron-modified multiwalled carbon nanotubes, mesoporous carbon, and alumina materials and their impact on the growth and yield of Zea mays L. in conjunction with Piriformospora indica under greenhouse conditions. The nanomaterials were prepared using the impregnation method and were characterized to confirm their nano size. Under greenhouse conditions, plants treated with nanomaterials and colonized by Piriformospora indica exhibited improvements in root length (≌2.5 times), shoot length (≌1.8 times), root biomass (≌3.5 times), shoot biomass (≌ 2.3 times), chlorophyll content (≌ 3 times), proline accumulation (≌ 2.5 times), and a reduction in lipid peroxidation compared to untreated Zea mays L. plants. This suggests that the combined application of nanomaterials and the multifaceted fungus can positively influence plant growth and yield. [ABSTRACT FROM AUTHOR]

There is a growing interest in developing agricultural practices that can improve crop performance while preserving natural resources. Plant biostimulants are thought to play a role in reaching this goal, in particular by increasing the nitrogen use efficiency. However, a notable research gap exists concerning the effects of foliar applications of natural zeolites as plant biostimulants on crop performance. To address this knowledge gap, a greenhouse experiment was set up in order to study the response of maize and wheat traits, specifically the biomass productivity and nitrogen uptake, as well as the response of soil extracellular enzymes to the foliar applications of a natural zeolite in combination with different levels of nitrogen fertilization, that is, 100%, 75%, and 50% of the optimal dose. Foliar application of zeolite in wheat and maize plants led to an increase in root nitrogen concentration of about 10%, particularly at the lowest nitrogen fertilization rate. This response was accompanied by an increase in aboveground to belowground uptake nitrogen ratio. Furthermore, there was a significant reduction of about 20% in root biomass in both crops with zeolite application across the entire nitrogen fertilization gradient. These plant-level responses were associated with a significant increase in the activity of carbon-degrading and nitrogen-degrading enzymes at the soil level in response to zeolite applications. Our findings provide a compelling proof-of-concept for the beneficial effects of foliar-applied zeolite as a biostimulant for crops, emphasizing the critical need for additional field research to validate our greenhouse results. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

SUMMARY: Seed number and harvesting ability in maize (Zea mays L.) are primarily determined by the architecture of female inflorescence, namely the ear. Therefore, ear morphogenesis contributes to grain yield and as such is one of the key target traits during maize breeding. However, the molecular networks of this highly dynamic and complex grain‐bearing inflorescence remain largely unclear. As a first step toward characterizing these networks, we performed a high‐spatio‐temporal‐resolution investigation of transcriptomes using 130 ear samples collected from developing ears with length from 0.1 mm to 19.0 cm. Comparisons of these mRNA populations indicated that these spatio‐temporal transcriptomes were clearly separated into four distinct stages stages I, II, III, and IV. A total of 23 793 genes including 1513 transcription factors (TFs) were identified in the investigated developing ears. During the stage I of ear morphogenesis, 425 genes were predicted to be involved in a co‐expression network established by eight hub TFs. Moreover, 9714 ear‐specific genes were identified in the seven kinds of meristems. Additionally, 527 genes including 59 TFs were identified as especially expressed in ear and displayed high temporal specificity. These results provide a high‐resolution atlas of gene activity during ear development and help to unravel the regulatory modules associated with the differentiation of the ear in maize. Significance Statement: This article will provide a full transcriptional landscape of maize ear during its whole development period. [ABSTRACT FROM AUTHOR]

In maize, blue and red light are key environmental factors regulating cell-cycle progression. We used transcriptomics to investigate and compare differential gene expression under the four light conditions: red light, blue light, red converted to blue and blue converted to red. A total of 23 differentially expressed genes were identified. The gene–gene interaction analysis indicated a significant interaction between four unidentified genes, 100191551 , pco143873 , 100284747 and pco060490 , and cell-cycle-related genes. Using multiple sequence alignment analysis and protein structure comparisons, we show here that these four unidentified genes were characterized as ALP1-like , ALP1 , cyclin P1-1 and AEBP2 , respectively. By constructing a protein–protein interaction network, we inferred that 100191551 and pco143873 are potentially regulated to avoid DNA damage by abiotic stress response factors in the cell cycle. The gene 100284747 regulates the cell cycle in response to phosphate starvation signalling. The gene pco060490 potentially negatively regulates the cell cycle through the mediation of Histone H3 and CYCD6 in response to red light. In conclusion, the cell-cycle-related genes are sensitive to blue and red light, and four novel functional genes may be involved in the cell cycle. [ABSTRACT FROM AUTHOR]

The menace of low soil nitrogen poses a significant challenge to maize production in sub-Saharan Africa, necessitating the development of high-yielding hybrids with increased nitrogen (N) tolerance. Two hundred and forty (240) maize hybrids were evaluated across eight environments at Zaria and Mokwa in Nigeria during the 2020 and 2021 growing seasons, encompassing both low- and optimum-N conditions. The primary objective of the study was to identify high-yielding, stable, and low-N-tolerant hybrids for potential adoption in Nigeria. The study results underscored the significant impact of nitrogen availability on various agronomic traits, causing a substantial 53% reduction in grain yield. Significant genetic variation was observed among hybrids for most measured traits. SMLW146 × IITA1878, SMLW147 × SAM50M and SMLW147 × IITA1878 were the highest-yielding hybrids across the test environments with a yield advantage of 48.2%, 46.6% and 43.1%, respectively over the best check. GGE biplot analysis identified Mokwa Low-N 2021 (MLN21) and Mokwa optimum-N 2021 (MOP21) as discriminating and representative environments for selecting superior hybrids. SMLW147 × SAM50M emerged as the most stable low-N tolerant hybrid with the highest yield performance. Conversely, hybrid SMLW147 × IITA1878 produced a high yield across environments but was unstable. The study concludes by recommending SMLW147 × SAM50M for cultivation across both low- and optimum-N conditions, while SMLW147 × IITA1878 is specifically recommended for cultivation in optimum-N environments. Anthesis-silking interval, plant aspect, ear aspect, and ear height were identified as the most suitable secondary traits for selecting hybrids for high grain yield under low-N conditions. [ABSTRACT FROM AUTHOR]

The field experiment was conducted on one of the private farms located in Al- Musauib project area, 40 km north of Babylon Governorate, during the spring and autumn seasons of 2022. To know the effect ofspraying gibberellin and thiamine and spraying stages on the growth and yield of corn. The experiment wasimplemented according to the split plots arrangement, and the treatments were distributed using the Randomized complete block design (R.C.B.D) with three replicates. The data were analyzed statistically according to the analysis of variance method, and the arithmetic means were compared using the least significant difference test (L.S.D) at a probability level of 0.05. Where the main plot included three stages of addition and they were (the stage of formation of 4 leaves, the stage of formation of 8 leaves, the stage of flowering) and symbolized by the symbols (A1, A2, A3). The subplot included spray concentrations and were as follows: spraying with distilled water only, gibberellin at a concentration of 100 mg.L-1 and thiamine (vitamin B1) at a concentration of 100 mg.L-1 and the interaction between gibberellin at a concentration of 100 mg.L-1 and thiamine 100 mg.L-1, and symbolized by (B0, B1, B2, B3) and the results were asfollows :The stage of formation of 8 leaves (A2) excelled significantly and gave the highest average for most of the studied traits and for both season, respectively. Total plant yield (181.07 and 175.01) kg.ha-1, biological yield (548.81 and 529.83). 3 treatments were significantly excelled on the rest of the other treatments and gave the highest mean of the two roots, respectively, for the traits of plant height (141.97 and 146.26) cm, leaf area (6778.96 and 6718.31) cm², stem diameter (2.55 and 2.41) cm, total plant yield (201.56 and 195.49) kg.ha-1, biological yield (625.71 and 605.90). The results also showed that the interaction between the study factors had a significant effect. The interaction treatments (A2 + B3) excelled and gave the highest values for most growth, yield and qualitative traits. [ABSTRACT FROM AUTHOR]

The objective of this work was to adapt the FT Raman spectroscopy analysis in the differentiation of haploid and diploid kernels in maize, developing a new efficient, agile, precise, and nondestructive methodology. The main difference observed in FT Raman readings was a peak in the region between 1600 and 1700 cm−1 in possibly haploid kernels. It was possible to correlate the characteristics of the kernels with the presence of the R1‐nj gene and the readings obtained in the Raman spectrometry technique. Most of the kernels previously classified as haploid showed positive values for principal component analysis (PCAs), indicating a correlation in the identification of haploids by the techniques adopted. The identification of haploids by R‐Navajo was superior to FT Raman. However, FT Raman spectroscopy is an agile analysis technique that enables the development of non‐invasive and non‐destructive analytical methods in maize kernels, in addition to providing relevant information about the chemical structures present in the composition of the samples. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The agricultural production system faces two main challenges: sustainability and climate change. For greater profitability, they must trade off against one another. To reduce the dependence on non-renewable resources, agricultural energy efficiency needs to be increased. Additionally, weed control is crucial to sustainability. In order to evaluate the energy balance, major energy indicators and profitability of maize under various weed control strategies, the current study was carried out. Therefore, a field experiment was carried out at farmers’ field in Kurmalur village of Perambalur District, Tamil Nadu, India during Kharif season of 2021 in order to evaluate different weed management practices on production and energy analysis of maize. The field experiment was laid out with ten treatments with three replications. The treatments consist of control, hand weeding on 15 and 30 DAS, pre-emergence application of atrazine, post emergence application of tembotrine, 2,4-D, halosulfuron methyl, Tembotrine, Mesotrione + Atrazine. Pre emergence application of Atrazine 1 kg/ha on 3 DAS fb Post emergence application of Tembotrine 105 g/ha on 20 DAS recorded the highest grain (4469 kg/ha) and straw yield (5708 kg/ha) with Net energy (156860 MJ/ha) and Energy Use Efficiency (14.55). [ABSTRACT FROM AUTHOR]

The use of biofertilizers applied via the foliar route has been highlighted as a positive nutrition complement, with variable responses according to the interaction between the plant (phenological phase), product composition (origin and processing) and year of cultivation. In this study, the objective was to evaluate the agronomic performance of corn under foliar application of biofertilizer in different phenological stages. The experiments were conducted for two consecutive years in the state of Minas Gerais (Uberlândia, Brazil), using two hybrids P30K75 and Status in 2018 and 2019, respectively. The nutritional managements were: (i): foliar biofertilizer at the dose of 0.5 L ha−1 in stage V4 (FBF 0.5 V4); (ii): foliar biofertilizer at the dose of 1.0 L ha−1 in stage V4 (FBF 1.0 V4); (iii) foliar biofertilizer at the dose of 0.5 L ha−1 in the V4 stage and 0.5 L ha−1 in the V8 stage (FBF 1.0 V4), and Control without biofertilizer application. All treatments were performed in the two years of cultivation. The application of foliar biofertilizer based on natural fungal extract and nutrients is favorable to corn productivity. The application of 0.5–1.0 L ha−1 in stage V4 generates increments between 9.9 and 13.8% in productivity. [ABSTRACT FROM AUTHOR]

Maize silage is a key component of feed rations in dairy systems due to its high forage and grain yield, water use efficiency, and energy content. However, maize silage nutritive value can be compromised by in-season changes during crop development due to changes in plant partitioning between grain and other biomass fractions. The partitioning to grain (harvest index, HI) is affected by the interactions between genotype (G) × environment (E) × management (M). Thus, modelling tools could assist in accurately predicting changes during the inseason crop partitioning and composition and, from these, the HI of maize silage. Our objectives were to (i) identify the main drivers of grain yield and HI variability, (ii) calibrate the Agricultural Production Systems Simulator (APSIM) to estimate crop growth, development, and plant partitioning using detailed experimental field data, and (iii) explore the main sources of HI variance in a wide range of G × E × M combinations. Nitrogen (N) rates, sowing date, harvest date, plant density, irrigation rates, and genotype data were used from four field experiments to assess the main drivers of HI variability and to calibrate the maize crop module in APSIM. Then, the model was run for a complete range of G × E × M combinations across 50 years. Experimental data demonstrated that the main drivers of observed HI variability were genotype and water status. The model accurately simulated phenology [leaf number and canopy green cover; Concordance Correlation Coefficient (CCC)=0.79-0.97, and Root Mean Square Percentage Error (RMSPE)=13%] and crop growth (total aboveground biomass, grain + cob, leaf, and stover weight; CCC=0.86-0.94 and RMSPE=23-39%). In addition, for HI, CCC was high (0.78) with an RMSPE of 12%. The long-term scenario analysis exercise showed that genotype and N rate contributed to 44% and 36% of the HI variance. Our study demonstrated that APSIM is a suitable tool to estimate maize HI as one potential proxy of silage quality. The calibrated APSIM model can now be used to compare the inter-annual variability of HI for maize forage crops based on G × E × M interactions. Therefore, the model provides new knowledge to (potentially) improve maize silage nutritive value and aid genotype selection and harvest timing decision-making. [ABSTRACT FROM AUTHOR]

Argentina is globally recognized as both producer and exporter of maize, the most important cereal crop in the country. Several potyviruses affect the production of various crops, including maize. In this work, the complete nucleotide sequences of the RNA genome of three potyviruses, johnsongrass mosaic virus (JGMV), maize dwarf mosaic virus (MDMV) and sugarcane mosaic virus (SCMV), isolated from maize were obtained by next‐generation sequencing (Illumina technology). The JGMV, MDMV and SCMV viral genomes were 9780, 9807 and 9729 nucleotides long, respectively. The polyprotein organization of each of potyvirus genome was determined; their sequences showed high values compared with polyprotein sequences of the other isolates reported worldwide (> 76.1% at the nucleotide sequence and > 85% at the amino acid sequence). The results of this work are the first data in Argentina of complete genome sequences of potyviruses obtained from maize and the first obtained for JGMV and MDMV. [ABSTRACT FROM AUTHOR]

Five direct and reciprocal early hybrids, five direct and reciprocal late hybrids and a total of their 12 parental inbred lines were used in order to test reciprocal effects among hybrids in early germination phase and seed quality of their parental inbred lines. Five hybrids were of early maturity FAO 300-400 group, and five of late maturity FAO 500-600 group. In the early group one line of Lancaster origin (L1) was in common, and in direct crosses used as male parent, while in reciprocal crosses as female parent. The same case was with late hybrids where another Lancaster line (L2) was in common. In 2015 and 2016 all the material was multiplied in hand pollination and after six months of storage three tests according to ISTA standards were performed: standard germination test (SGT), cold-test (CT) and vigor radicle test (RE). According to the Analysis of variance, a strong reciprocal effect was found among early hybrids for four out of five parameters in RE and SGT, while it was found only for RE in late hybrids. However, in CT none of the parameters had significant reciprocal effect. Two tested Lancaster inbreds were superior in the hybrids over non-Lancaster lines when used as maternal components, while as lines per se they did not display such superiority. Mid-parent heterosis (MPH) ranged from -62.32% to 211.11% in RE test, with an average of 44.26%; from -10.15% to 17.93% in SGT test, with an average of 6.27%, and from -5.31% to 4.49% in CT, with an average of 0.64%. Significant differences of MPH were found for nine pairs of reciprocal hybrids for RE, three pairs for SGT and seven pairs for CT. This shows that reciprocal differences in MPH were higher as the applied level of stress during early seed growth raised. All the results showed very complicated mode of inheritance of tested traits in the early developmental stages of young plants, including the phenomenon of heterosis which is expressed already at the germination stage. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this work was to assess the effects of A. brasilense inoculation on seeds on the yield performance of maize and black oat as a function of nitrogen rate over a 3-year succession. The experiment was conducted from 2015 to 2018 under field conditions. Maize was grown for three growing seasons in rotation with two seasons of black oat at the same experimental site. A randomized block design with a split-plot arrangement was used. Main plots consisted of A. brasilense inoculation (inoculated and uninoculated plants) and subplots of four nitrogen rates (0, 40, 80, and 120 kg ha-1). Maize plants were evaluated for biometric parameters, yield, and yield components at flowering. Black oat plants were analyzed for dry matter yield at flowering. The inoculation of A. brasilense in maize and black oat seeds in succession does not promote productivity nor does it favor the nitrogen fertilization of these cultures. [ABSTRACT FROM AUTHOR]

The most widely used production systems in the Cerrado region are soybean (Glycine max)-corn (Zea mays) and soybean-corn intercropped with ruzigrass [Urochloa ruziziensis (Syn. Brachiaria ruziziensis)]. Thus, these systems may require a higher supply of mineral nitrogen (N) fertilizer. Therefore, the objective of this study was to evaluate the agronomic traits of two corn cultivars grow in the second-crop harvest in different environments, production systems, and N application rates in an Oxisol in the Cerrado region of Mato Grosso do Sul. The experimental design was a randomized block arranged in a split-split plot with three replicates. Plots consisted of two environments (UFMS 1 and UFMS 2), subplots consisted of two production systems [corn alone (monoculture) or corn intercropped with U. ruziziensis, and sub-subplots of five N application rates in topdressing (0, 40, 80, 120, or 160 kg N/ha). Urea was used as the source of N (45% N), and it was applied 30 days after emergence (DAE). Two corn cultivars (NS50 and Invictus Viptera 3) were used. During the flowering period of corn (i.e., after the emergence of female inflorescence), the relative chlorophyll index, leaf N concentration, plant height, and ear insertion height were recorded. At physiological maturity, the ear insertion height, ear length, number of grain rows per ear, number of grains per row, ear diameter, mass of one thousand grains, and grain yield were measured. The corn grain yield is lower in the system intercropped with U. ruziziensis when compared to the cultivation of corn alone (monoculture). In addition, the environment with greater soil base saturation and N availability (UFMS 2) results in a distinct response for the corn cultivar used; thus, a greater grain yield is expected from cultivar Viptera 3 in this environment. The maximum agronomic efficiency for corn grain yield is obtained with 102 to 123 kg N/ha for the Viptera 3 and NS50 PRO cultivars, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The modification of starch with the heat moisture treatment (HMT) method increases the level of type 3 resistant starch, which is used to develop functional foods such as analog rice. Therefore, this study aims to analyze the physicochemicals of analog rice made of modified arrowroot starch (Maranta arundinacea L.) and corn flour (Zea mays L.) with seaweed (Gracilaria sp.). It was conducted using a factorial randomized block design method of two factors. The first factor was the difference in the ratio of the composition of modified arrowroot and corn flour, which consisted of three levels, namely 30:70, 40:60, and 50:50. Meanwhile, the second factor was the concentration of seaweed porridge with three levels, namely 1 %, 2 %, and 3 %. The results showed that increasing the proportion of modified arrowroot starch and the concentration of seaweed porridge reduced water, fat, protein, and ash contents but increased analog rice resistant starch levels. Furthermore, the antioxidant activity of analog rice also increased after steaming. This study has proven that using modified arrowroot starch, corn flour, and the addition of seaweed can improve the functional properties of analog rice. [ABSTRACT FROM AUTHOR]

Background: Though modern high yielding and synthetics developed through maize heterosis are replacing low-yielding maize populations worldwide, it has shown little impact in Kashmir due to poor adaptability and expensive seed cost. Nevertheless, retaining popularity due to adaptability, more resistance to natural factors, early maturity, good grain quality, great food and fodder value and ability to thrive best under low input conditions, landraces are going out of farmer's domain and becoming extinct owing to low yielding potential, low resilience to some biotic stresses and lower sensitivity to inputs. For developing high yielding, climate-resilient cultivars and broadening of the genetic base, efficient and rapid identification and introgression of novel and favourable alleles dispersed among the landraces are necessary. Methods: Seventy maize landraces from different parts of Kashmir valley designated as K-L1 to K-L70 were subjected to genetic analysis for thirteen important agronomic traits viz. days to 50% tasselling, days to 50% silking, anthesis-silking interval, plant height, ear height, days to maturity, ear diameter, kernel rows per ear, kernels per row, prolificacy, shelling percentage, yield per hectare and 100-grain weight. The least significance increase was calculated to evaluate best performing landraces and clustering of landraces was done using Mahalanobis D2 analysis through Tocher's method. The experimentation was carried out at Dryland Agriculture Research Station Budgam during the years 2019 and 2020. Result: Significant differences for all agronomic traits except anthesis-silking interval and prolificacy depicted the presence of significant genetic variability. The least significant increase calculations allowed the evaluation of best-performing landraces for specific traits and Mahalanobis D2 analysis through Tocher's method led to clustering landraces into 14 clusters with cluster I having the highest 23, followed by cluster VI with 14, cluster II and cluster III each with 9, cluster VIII with 6 genotypes and rest 9 clusters being monogenotypic. Intra and inter-clustering distance and cluster means suggest utilizing genotypes belonging to clusters with wider statistical distances for crossing in hybridization programme to produce segregates with extensive variation resulting in higher heterosis. [ABSTRACT FROM AUTHOR]

To evaluate the effect of planting method (PM), planting date (PD), and cultivar (CV) on the grain and herbage yield, irrigation water use efficiency for herbage (IWUEH) and grain (IWUEG), and grain quality of maize, a two-year field study was conducted at the Research Farm of Seed and Plant Improvement Institute, Karaj, Iran, during the 2017 and 2018 growing seasons. The experiment was arranged as split-plot factorial with three planting dates, including PD1 (July 1st), PD2 (July 11th), and PD3 (July 23rd) as main plots. Three planting methods, including direct seeding (DS), seed hydro-priming (HP), and transplanting (TP), were factorially combined with two maize cultivars (S.C.704 and S.C.260) as sub-plots. The highest herbage and grain yields (76685 and 7369 kg ha-1, respectively) and the maximum IWUE for herbage and grain production (13.1 and 1.21 kg m-3, respectively) were found in the TP. The CV S.C.704 obtained a higher grain yield (GY) on PD1 than that of S.C.260, but as planting was delayed, the GY of S.C.704 was affected more negatively in both years. Delay planting enhanced IWUEH, but not IWUEG. The highest IWUEG was obtained from TP on each PD. The CV S.C.260 in delay planting resulted in better IWUEG in both years. The highest and lowest contents of crude protein, starch, ash, crude fiber, and oil were obtained from hydro-primed and transplanted maize, respectively. In conclusion, the yield in the transplanting method had superiority over DS and HP. Also, HP was found to be the optimal PM to enhance the grain quality of maize in delayed planting. Furthermore, selecting S.C.260 as a high-yielding hybrid on delayed planting is suggested. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The identification of genomic regions associated with root traits and the genomic prediction of untested genotypes can increase the rate of genetic gain in maize breeding programs targeting roots traits. Here, we combined two maize association panels with different genetic backgrounds to identify single nucleotide polymorphisms (SNPs) associated with root traits, and used a genome-wide association study (GWAS) and to assess the potential of genomic prediction for these traits in maize. For this, we evaluated 377 lines from the Ames panel and 302 from the Backcrossed Germplasm Enhancement of Maize (BGEM) panel in a combined panel of 679 lines. The lines were genotyped with 232 460 SNPs, and four root traits were collected from 14-day-old seedlings. We identified 30 SNPs significantly associated with root traits in the combined panel, whereas only two and six SNPs were detected in the Ames and BGEM panels, respectively. Those 38 SNPs were in linkage disequilibrium with 35 candidate genes. In addition, we found higher prediction accuracy in the combined panel than in the Ames or BGEM panel. We conclude that combining association panels appears to be a useful strategy to identify candidate genes associated with root traits in maize and improve the efficiency of genomic prediction. [ABSTRACT FROM AUTHOR]

Common smut, caused by Ustilago maydis (DC.) Corda, is a destructive fungal disease of maize worldwide; it forms large tumors, reducing corn yield and quality. However, the molecular defense mechanism to common smut in maize remains unclear. The present study aimed to use a leading maize inbred line Ye478 to analyze the response to U. maydis inoculation. The histological and cytological analyses demonstrated that U. maydis grew gradually to the host cells 6 h post-inoculation (hpi). The samples collected at 0, 3, 6, and 12 hpi were analyzed to assess the maize transcriptomic changes in response to U. maydis. The results revealed differences in hormone signaling, glycometabolism, and photosynthesis after U. maydis infection; specific changes were detected in jasmonic acid (JA), salicylic acid (SA), ethylene (ET), and abscisic acid (ABA) signaling pathways, glycolysis/gluconeogenesis, and photosystems I and II, probably related to defense response. MapMan analysis demonstrated that the differentially expressed genes between the treatment and control groups were clustered into light reaction and photorespiration pathways. In addition, U. maydis inoculation induced chloroplast swelling and damage, suggesting a significant effect on the chloroplast activity and subsequent metabolic process, especially hexose metabolism. A further genetic study using wild-type and galactinol-sucrose galactosyltransferase (gsg) and yellow-green leaf-1 (ygl-1) mutants identified that these two U. maydis-induced genes negatively regulated defense against common smut in maize. Our measurements showed the pathogen early-invasion process, and the key pathways of both chlorophyll biosynthesis and sugar transportation were critical modified in the infected maize line, thereby throwing a light on the molecular mechanisms in the maize-U. maydis interaction. [ABSTRACT FROM AUTHOR]

The analysis of main additive effects and multiplicative interaction is commonly used in the evaluation of the genotype x environment interaction, however, its application can be used for other purposes, as it is performed in the presentresearch, which uses this technique in the selection of inbred lines, testers and hybrids in maize topcrosses. Thisresearch determined the effect of the inbred lines x testers interaction through the analysis of main additive effects and multiplicative interaction, verifying their efficiency in the selection of inbred lines, testers and hybrid combinations in topcrosses. The trials were carried out in the 2015/16 and 2016/17 crop seasons, with a complete block design, with three replications. Thirty S3 maize inbred lines were evaluated in crosses with the AG8025, P30B39, MLP102, 60.H23.1 and 70.H26.1 testers forming 150 hybrids topcrosses. The trait evaluated was grain yield. The adaptability and stability of testers and inbred lines were evaluated by the methodology of analysis of main additive effects and multiplicative interaction directed to the interaction of testers x inbred lines. The 96.3 inbred line has the most homogeneous performance and the highest grain yield, considering the crossing with all testers in both environments. The 70.H26.1 tester is considered the most stable and the most recommended for topcrosses. The best specific combinations were 96.3 x 70.H26.1 and 96.3 x 60.H23.1. [ABSTRACT FROM AUTHOR]

Formulating optimum quantity of nitrogen fertilization is highly necessary to attain higher yields in maize. As per soil fertility, the right dosage has to be formulated for each region with consciousness on the soil and environmental health. A field experiment was conducted during 2018-19 under mild tropical plain agroclimatic conditions of Arunachal Pradesh, India to investigate the effect of different nitrogen doses on growth and yield of maize. The experiment was laid out under randomized block design with five replicated plots for each treatment. The nitrogen through urea was supplied with different doses of 0, 100, 120, 150 and 180 kg/ha. The crop was evaluated for plant height, number of leaves, leaf length, number of kernels per cob, number of rows per cob, and total grain yield. The results revealed that the variables such as plant height, number of leaves, leaf length, number of kernels per cob, number of rows per cob and total grain yield were significantly (P<0.05) affected by the different levels of nitrogen doses. Number of leaves, leaf length and crop yield were highest in 180 kg/ha (nitrogen dose), while lowest in control which significantly increased with higher nitrogen doses. This result showed that nitrogen with higher doses was more effective than low doses for maize crop. Nitrogen fertilization at 180 kg/ha exerted a significantly higher and positive effect on maize growth and can be recommended for the region. [ABSTRACT FROM AUTHOR]

Climate change can trigger excessive rainfall, making mechanized soybean harvesting unfeasible. The off-season maize cultivation can benefit from soybean-maize rotation system, inoculated with Bradyrhizobium spp. strains, as a potential biological source of nitrogen (N). To meet the nutritional demand of maize crops, N fertilization management is essential. Recent research has sought to understand how maize cultivars respond to mineral N application. In this work, we used a modern methodology to select maize cultivars with greater response to different application inputs of mineral N fertilizer, including N derived from soybean crop residues. We used the Manhattan distance to verify the similarity between the responses of four maize cultivars (30F53VYHR, AG8700 PRO3, B2433PWU, and SYN7G17 TL) that were either unfertilized or fertilized with 40, 80, 120, and 160 kg N ha−1. The Technique for Order of Preference by Similarity to the Ideal Solution method was applied to select the most responsive cultivar. Among the four maize cultivars, SYN7G17TL and AG8700PRO3 are more responsive to N fertilizer application in medium and high-fertility agricultural soils, respectively. When soil fertility levels are disregarded, the AG8700PRO3 cultivar has greater potential response to N fertilization, agreeing with previous studies. The proposed approach is easy to use and adapt and provides an appropriate mechanism for selecting maize cultivars sown in areas with soybean residues, thus contributing to more sustainable planting as it adequately assesses nitrogen management. [Display omitted] • New methods for cultivar selection are crucial for efficient nitrogen management; • Corn cultivars vary with nitrogen. Our selection method is inevitable. • Our method aid in precise cultivar selection for nitrogen responsiveness; • The cultivars response varies with fertility. Our selection method is necessary; • The results agree with previous studies, validating the selection methodology; [ABSTRACT FROM AUTHOR]

The agricultural land in the Indian Himalayan region (IHR) is susceptible to various spells of snowfall, which can cause nutrient leaching, low temperatures, and drought conditions. The current study, therefore, sought an indigenous psychrotrophic plant growth-promoting (PGP) bacterial inoculant with the potential to alleviate crop productivity under cold and drought stress. Psychrotrophic bacteria preisolated from the night-soil compost of the Lahaul Valley of northwestern Himalaya were screened for phosphate (P) and potash (K) solubilization, nitrogen fixation, indole acetic acid (IAA) production, siderophore and HCN production) in addition to their tolerance to drought conditions for consortia development. Furthermore, the effects of the selected consortium on the growth and development of wheat (Triticum aestivum L.) and maize (Zea mays L.) were assessed in pot experiments under cold semiarid conditions (50 % field capacity). Among 57 bacteria with P and K solubilization, nitrogen fixation, IAA production, siderophore and HCN production, Pseudomonas protegens LPH60, Pseudomonas atacamensis LSH24, Psychrobacter faecalis LUR13, Serratia proteamaculans LUR44, Pseudomonas mucidolens LUR70, and Glutamicibacter bergerei LUR77 exhibited tolerance to drought stress (-0.73 MPa). The colonization of wheat and maize seeds with these drought-tolerant PGP strains resulted in a germination index >150, indicating no phytotoxicity under drought stress. Remarkably, a particular strain, Pseudomonas sp. LPH60 demonstrated antagonistic activity against three phytopathogens Ustilago maydis, Fusarium oxysporum, and Fusarium graminearum. Treatment with the consortium significantly increased the foliage (100 % and 160 %) and root (200 % and 133 %) biomasses of the wheat and maize plants, respectively. Furthermore, whole-genome sequence comparisons of LPH60 and LUR13 with closely related strains revealed genes associated with plant nutrient uptake, phytohormone synthesis, siderophore production, hydrogen cyanide (HCN) synthesis, volatile organic compound production, trehalose and glycine betaine transport, cold shock response, superoxide dismutase activity, and gene clusters for nonribosomal peptide synthases and polyketide synthetases. With their PGP qualities, biocontrol activity, and ability to withstand environmental challenges, the developed consortium represents a promising cold- and drought-active PGP bioinoculant for cereal crops grown in cold semiarid regions. • Out of 57 isolates, 11 psychrotrophic bacteria exhibited efficient PGP abilities. • Six strains resist drought stress, promoting seed germination without phytotoxicity. • Pseudomonas protegens LPH60 exhibited biocontrol activity against phytopathogens. • Consortium treatment significantly boosts wheat and maize foliage and root biomass. • Genomic data asserted the presence of genes contributing to plant-beneficial traits. [ABSTRACT FROM AUTHOR]

Purpose: The objective was to evaluate soluble sources of silicon (Si) applied through fertigation in mitigating water deficit in maize plants. Another objective was to determine the physiological and nutritional effects involved. Methods: The study was carried out in a greenhouse in pots filled with Oxisol. The treatments were arranged in a 3 x 2 factorial scheme, consisting of Si supply from soluble sources: sodium and potassium silicate stabilized with sorbitol (Si-alkali), potassium silicate (Si-K), plus the control (absence of Si); and two soil water regimes: 70% (without deficit) and 30% (severe water deficit) of soil water retention capacity. The experiment used a randomized block design, with six replications. Si was supplied at a concentration of 2 mmol L-1, applied through fertigation. Four applications were performed, starting at 12 days after seedling emergence. Results: The soluble sources of Si applied through fertigation promoted the uptake of this element by maize plants even under water restriction. Si mitigated the damage caused by severe water deficit in maize plants because it kept the relative leaf water content, decreased the cell leakage index, and preserved the content of photosynthetic pigments, which increased quantum efficiency of photosystem II, content and use efficiency of macronutrients, thus leading to greater growth and biomass. Conclusion: The damage caused by severe water deficit in plants can be mitigated by using a relatively low supply of Si through fertigation. Si addition in irrigated crops improves the use of water resources, proving to be a strategy for sustainable agricultural production. [ABSTRACT FROM AUTHOR]

The fungus Aspergillus flavus causes serious damage to maize grains and its by-products, such as tortilla. Currently, animal and plant derivatives, such as chitosan and propolis, and plant extract residues, respectively, are employed as alternatives of synthetic fungicides. The objective of this research was to evaluate the efficacy of several formulations based on propolis-chitosan-pine resin extract on the in vitro growth of A. flavus, the growth of maize grain plantlets and the quality of stored tortillas at 4 and 28 °C. The most outstanding formulation was that based on 59.7% chitosan + 20% propolis nanoparticles + 20% pine resin extract nanoparticles; since the in vitro conidia germination of A. flavus did not occur, disease incidence on grains was 25–30% and in tortillas, 0% infection was recorded, along with low aflatoxin production (1.0 ppb). The grain germination and seedling growth were markedly reduced by the nanocoating application. The percentage weight loss and color of tortillas were more affected by this coating compared to the control, and the rollability fell within the scale of non-ruptured at 4 °C and partially ruptured at 28 °C. The next step is to evaluate the toxicity of this formulation. [ABSTRACT FROM AUTHOR]

Over the past century of maize (Zea mays L.) breeding, grain yield progress has been the result of improvements in several other intrinsic physiological and morphological traits. In this study, we describe (i) the contribution of kernel weight (KW) to yield genetic gain across multiple agronomic settings and breeding programs, and (ii) the physiological bases for improvements in KW for US hybrids. A global-scale literature review concludes that rates of KW improvement in US hybrids were similar to those of other commercial breeding programs but extended over a longer period of time. There is room for a continued increase of kernel size in maize for most of the genetic materials analysed, but the trade-off between kernel number and KW poses a challenge for future yield progress. Through phenotypic characterization of Pioneer Hi-Bred ERA hybrids in the USA, we determine that improvements in KW have been predominantly related to an extended kernel-filling duration. Likewise, crop improvement has conferred on modern hybrids greater KW plasticity, expressed as a better ability to respond to changes in assimilate availability. Our analysis of past trends and current state of development helps to identify candidate targets for future improvements in maize. [ABSTRACT FROM AUTHOR]

The nutritional status of plants affects the multitrophic plant-insect interactions, however to date, there is little evidence about such maize (Zea mays L.)- aphids interaction related to soil nitrogen content (N). Maize was cultivated under sufficient (15 mM) or limited (0.15 mM) nitrogen supply. We conducted the behavioural trials using a four-arm olfactometer and found that Rhopalosiphum padi L. preferred the maize grown under high-nitrogen conditions. The volatile organic compounds (VOCs) from maize were obtained from the plants grown under different nitrogen conditions and analyzed by gas chromatography-mass spectrometry (GC-MS). The relative amounts of (z)-2-hexenol, benzaldehyde and decane were significantly higher under highnitrogen (15 mM) conditions than under low-nitrogen (0.15 mM) conditions (limited) nitrogen supply) and these VOCs attracted the wingless aphids. Under low-nitrogen conditions, higher contents of farnesol, cadinol, aristolene and acetic acid were found, however, the farnesol and acetic acid repelled the aphids. Furthermore, Electroantennogram (EAG) studies confirmed that aphid antennae responded to these compounds. Expressions of certain key genes associated with the synthetic pathways of (E)-2-hexenol, benzaldehyde, acetic acid and copaene were verified by Quantitative Real-time polymerase chain reaction (qRT-PCR). The chemical ecology of the interactions between maize (Zea mays) and aphids (R. padi) under different nitrogen doses was investigated to formulate the new pest management strategies. [ABSTRACT FROM AUTHOR]

Response of foliar rates of macronutrients in corn under nitrogen fertilization and the effects of waste of co-inoculation with Azospirillum brasilense in soybeans are evaluated. Soybean was planted in two treatments, namely, inoculation of seeds with Bradyrizobium japonicum, with and without co-inoculation with Azospirillum brasilense, followed by corn. Treatments for corn crop consisted of a combination of residual inoculation of Bradyrhizobium japonicum and the residual co-inoculation with Azospirillum brasilense within the band (main factor) applied to soybean seeds and five doses of N (0, 50, 100, 150 and 200 kg ha-1) applied to second harvest, consorted with Urochloa ruziziensis in the splits (secondary factor). Foliar rate of N, P, K, Ca, Mg and S for corn crops was determined. Efficiency of nitrogen usage (EUN), recovery of applied nitrogen (RNA), agronomic efficiency of applied N (EA) and physiological efficiency (EF) were determined. Data underwent analysis of variance and means of quality factor (inoculation) were compared by F test, whilst polynomial regression was applied for quantitative factor (N doses). Corn inoculation residue did not increase the rate of corn foliar N. However, there was an increase according to the dose of applied N. In the case of other nutrients (P, Ca, Mg), foliar increase of nutrients was detected in most doses when compared to co-inoculation and interaction between inoculation factors and N doses. There was no increase in K and S when compared to co-inoculation residue. Residual co-inoculation with Azospirillum brasilense in soybean improves corn physiology cultivated in succession and generates plants with greater production potential coupled to greater stress tolerance. [ABSTRACT FROM AUTHOR]

Corn has great relevance worldwide due to its economic and social importance. Its production grows every harvest, and determining traits directly related to the grain yield is essential for crop management. The hypothesis of this study is that structural equation modelling (SEM) and factor analysis allow us to identify agronomic variables and vegetation indices (VIs) that most contribute to grain yield. Thus, the objective was to identify which agronomic traits and VIs are most associated with grain yield in corn using SEM and factor analysis. Field experiments were carried out during the 2017/2018 and 2018/2019 crop seasons. The experimental design was in randomized blocks with three replicates in a factorial scheme. The following agronomic traits were evaluated: ear length (EL), number of rows per ear (NRE), number of grains per row (NGR), plant height, ear insertion height, stem diameter, and grain yield. The VIs evaluated were: Normalized Difference Vegetation Index (NDVI), Normalized Difference Red Edge (NDRE), Green Normalized Difference Vegetation Index, Soil-Adjusted Vegetation Index (SAVI). Data were subjected to factor analysis and structural equation modelling. The EL, NGR, and NRE were the agronomic traits that most related to corn yield. The VIs most related to yield were NDVI, NDRE, and SAVI. By identifying which agronomic variables and VIs are the most related to grain yield in corn, this study contributes to the decision-making process on HTP in corn and consequently to a higher efficiency of corn breeding programs aiming at selecting high-yielding genotypes. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The light attenuation process within a plant canopy defines energy capture and vertical distribution of light and nitrogen (N). The vertical light distribution can be quantitatively described with the extinction coefficient (k), which associates the fraction of intercepted photosynthetically active radiation (fPARi) with the leaf area index (LAI). Lower values of k correspond to upright leaves and homogeneous vertical light distribution, increasing radiation use efficiency (RUE). Yield gains in maize (Zea mays L.) were accompanied by increases in optimum plant density and leaf erectness. Thus, the yield-driven breeding programs and management changes, such as reduced row spacing, selected a more erect leaf habit under different maize production systems (e.g. China and the USA). In this study, data from Argentina revealed that k decreased at a rate of 1.1% year–1 since 1989, regardless of plant density and in agreement with Chinese reports (1.0% year–1 since 1981). A reliable assessment of changes in k over time is critical for predicting (i) modifications in resource use efficiency (e.g. radiation, water, and N), improving estimations derived from crop simulation models; (ii) differences in productivity caused by management practices; and (iii) limitations to further exploit this trait with breeding. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effectiveness of arbuscular mycorrhizal fungi (AMF) in the absorption of nutrients in trapping culture and its effects on the growth and biomass production of corn (Zea mays L.) and sorghum (Sorghum sp.). Soil samples with rhizosphere were collected from three different places: Bambusa sp., Cichorium intybus L., and Pinus merkusii. The density and genus of AMF spores were evaluated. AMF effectiveness was tested using six levels of rhizosphere and two species (corn and sorghum) of plants with a 2×6 factorial experiment with eight replications of each treatment. Six types of rhizospheres were: (i) bamboo rhizosphere (Bambusa sp.) (T1), (ii) control for T1 (C1), (iii) chicory rhizosphere (C. intybus L.) (T2), (iv) control for T2 (C2), (v) Pine rhizosphere (P. merkusii) (T3), and (vi) control for T3 (C3). The control treatment was derived from sterilized planting media. The results showed that the root rhizosphere of Bambusa sp. had more density and diversity of AMF spores than the root rhizosphere of C. intybus L. and P. merkusii. At the end of the trapping culture, the host plants sorghum and corn increased the density of spores in the carrier medium or propagules of the three rhizosphere types. The difference in the amount of initial AMF had a significant (p<0.05) effect on plant height, the number of leaves, and the biomass production of trapping plants. It can be concluded that more density and colonization of arbuscular mycorrhizal spores show higher growth and biomass of trapping plants. [ABSTRACT FROM AUTHOR]