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Water stress can lead to physiological and morphological damage, affecting the growth and development of popcorn. The objective of this study was to identify the yield potential of 43 popcorn lines derived from a Latin American germplasm collection, based on agronomic and physiological traits, under full irrigation (WW) and water deficit conditions (WS), aiming to select superior germplasm. The evaluated agronomic traits included the ear length and diameter, number of grains per row (NGR) and rows per ear (NRE), grain yield (GY), popping expansion (EC), volume of expanded popcorn per hectare (VP), grain length (GL), width, and thickness. The physiological traits included the chlorophyll, anthocyanin, and flavonoid content in the leaves. The genetic variability and distinct behavior among the lines for all the agronomic traits under WW and WS conditions were observed. When comparing the water conditions, line L292 had the highest mean for the GY, and line L688 had the highest mean for the EC, highlighting them as the most drought-tolerant lines. A water deficit reduced the leaf greenness but increased the anthocyanin content as an adaptive response. The GY trait showed positive correlations with the VP, NGR, and GL under both water conditions, making the latter useful for indirect selection and thus of great interest for plant breeding targeting the simultaneous improvement of these traits.

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Corn is the second most cultivated crop in Brazil, the number-one country in pesticide consumption. Chemical control of weeds is performed using herbicides such as S-metolachlor with pre- and post-emergence action and thus the toxicity of herbicides constitutes a matter of great concern. The present investigation aimed to examine the effects of an S-metolachlor-based herbicide on Lactuca sativa L. (lettuce) and Zea mays L. (maize) utilizing various bioassays. The test solutions were prepared from commercial products containing the active ingredient. Seeds from the plant models were exposed in petri dishes and maintained under biochemical oxygen demand (BOD) at 24°C. Distilled water was negative and aluminium positive control. Macroscopic analyses (germination and growth) were conducted for both plant species, and microscopic analysis (cell cycle and chromosomal alterations) were performed for L. sativa root tip cells. Detrimental interference of S-metolachlor-based herbicide was noted with lettuce for all parameters tested reducing plant germination by over 50% and the germination speed by over 45% and showing a significant decrease in mitotic index, from 16.25% to 9,28% even on the lowest concentration tested. In maize, there was no significant interference in plant germination; however, speed of germination was significantly hampered, reaching a 51.22% reduction for the highest concentration tested. Data demonstrated that the herbicide was toxic as evidenced by its phyto- and cytotoxicity in L. sativa L. and Z. mays L.

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Maize tortilla is the best-recognized food product of Mexican gastronomy. Artisanal maize tortillas (AMT) are prepared with native maize varieties and a traditional process. The aims of this study were to identify sensory attributes, texture, and color in AMT that allow them to be differentiated from commercial tortillas, and to determine the chemical and mineral composition of both types of tortillas. Six landraces related to four Mexican maize races were used. Two commercial tortillas were included as references (tortillería and supermarket). Tortillas were subjected to sensory analysis by the modified Flash technique, texture and color were measured objectively and chemical and mineral analysis of all tortillas were evaluated. Lime taste and lime smell attributes were relevant to differentiate AMT from commercial tortillas; aftertaste and fracturability attributes were highly associated to supermarket tortillas. The fracturability attribute of tortillas is consider undesirable for taco preparation. Five of the six AMT were characterized by the presence of a layer, a characteristic that is associated with traditional tortilla made by Mexican consumer. Regarding chemical composition, supermarket tortillas exhibited the highest dietary fiber content (17.09%), but showed 30% more Na than AMT, with the exception of tortillas from Purepecha native variety. Besides, supermarket tortilla had 48.9% less Ca than AMT. The sensory attributes relevant to differentiate native maize tortillas from the commercial maize tortilla references were appearance, smell, and taste, while textural and color attributes played a lesser role.

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Zea mays L is a crucial crop for Brazil, ranking second in terms of production and sixth in terms of exports. In Brazil, the second season, or off-season, accounts for 80 % of the overall maize output, which primarily occurs after the soybean main season. A maize yield forecast model for the off-season was developed and implemented throughout Brazilian territory due to its importance to the country's economy and food security. The model was built using multiple linear regressions that connected outputs simulated from a land surface model used in large-scale analysis for agriculture (JULES-crop), to agrometeorological indicators. The application of the developed model occurred every 10 days from the sowing until the maturation. A comparison of the forecasting model was verified with the official off-season maize yields for the years 2003-2016. Agrometeorological indicators during the reproductive phase accounted for 60 % of the interannual variability in maize production. When outputs simulated by JULES-crop were included, the forecasting model achieved Nash-Sutcliffe modeling efficiency (EF) of 0.77 in the maturation and EF = 0.72 in the filling-grain stage, suggesting that this approach can generate useful predictions for final maize yield beginning on the 80th day of the cycle. Outputs of JULES crop enhanced modeling performance during the vegetative stage, reducing the standard deviation error in prediction from 0.59 to 0.49 Mg ha-1.

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Pigmented corn is a gramineae food of great biological, cultural and nutritional importance for many Latin American countries, with more than 250 breeds on the American continent. It confers a large number of health benefits due to its diverse and abundant bioactive compounds. In this narrative review we decided to organize the information on the nutrients, bioactive compounds and phytochemicals present in pigmented corn, as well as their effects on human health. Phenolic compounds and anthocyanins are some of the most studied and representative compounds in these grasses, with a wide range of health properties, mainly the reduction of pro-oxidant molecules. Carotenoids are a group of molecules belonging to the terpenic compounds, present in a large number of pigmented corn breeds, mainly the yellow ones, whose biological activity incorporates a wide spectrum. Bioactive peptides can be found in abundance in corn, having very diverse biological effects that include analgesic, opioid and antihypertensive activities. Other compounds with biological activity found in pigmented corn are resistant starches, some fatty acids, phytosterols, policosanols, phospholipids, ferulic acid and phlobaphenes, as well as a great variety of vitamins, elements and fibers. This review aims to disseminate and integrate the existing knowledge on compounds with biological activity in pigmented corn in order to promote their research, interest and use by scientists, nutrition professionals, physicians, industries and the general population.

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The growing demand for gluten-free products requires the study of alternatives to produce nutritionally and technologically favorable foods. The aim was to evaluate the content and antioxidant capacity of gluten-free bread enriched with whole flour of purple maize (PM) and how starch and bioaccessibility of antioxidant compounds were modified during in vitro digestion. Gluten-free bread was prepared with the addition of 34%, 50%, and 70% PM, and white maize bread served as control. The content of total polyphenols, anthocyanins, and antioxidant capacity through FRAP and TEAC was measured. Specific volume, crumb texture, and starch digestibility were determined in the breads. Simultaneously, in vitro digestion and dialysis by membrane were performed to evaluate the bioaccessible and potentially bioavailable fraction. Bread with 34% PM had a similar specific volume and crumb texture to the control, but higher content of polyphenols (52.91 mg AG/100 g), anthocyanins (23.13 mg c3-GE/100 g), and antioxidant capacity (3.55 and 5.12 µmol tr/g for FRAP and TEAC, respectively). The PM breads had a higher antioxidant content and capacity and higher slowly digestible and resistant starch than the control. These parameters increased as the PM proportion rose. After digestion, anthocyanins were degraded, polyphenols and antioxidant capacity decreased, but they remained potentially bioavailable, although to a lesser extent. Bread with 34% shows acceptable technological parameters, lower starch digestibility, and contribution of bioactive compounds with antioxidant capacity. This indicates that purple maize flour represents a potential ingredient to produce gluten-free bread with an improved nutritional profile.

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This study reports the first occurrence of Leptodelphax maculigera (Stål, 1859) in Brazil and the Americas. Until now, this species has not been reported outside of Africa. The notification occurred in the State of Goiás in species of agronomic importance, as corn, Brachiaria, elephant grass, cultivar BRS Capiaçu and beans. The identification of the species was carried out through the morphological analysis of the male terminalia. This species has been found in maize plants, were sharing the same space with another wellknown species of great economic importance to crop, Dalbulus maidis (DeLong & Wolcott). Thus, the confirmed presence of L. maculigera in Brazil and the morphological distinction of the two species are key factors for establishing Integrated Pest Management (IPM) in the areas where it is found.

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Bacterial inoculants have been used in agriculture to improve plant performance. However, laboratory and field requirements must be completed before a candidate can be employed as an inoculant. Therefore, this study aimed to evaluate the parameters for inoculant formulation and the potential of Bacillus subtilis (B70) and B. pumilus (B32) to improve phosphorus availability in maize (Zea mays L.) crops. In vitro experiments assessed the bacterial ability to solubilize and mineralize phosphate, their adherence to roots, and shelf life in cassava starch (CS), carboxymethyl cellulose (CMC), peat, and activated charcoal (AC) stored at 4 °C and room temperature for 6 months. A field experiment evaluated the effectiveness of strains to increase the P availability to plants growing with rock phosphate (RP) and a mixture of RP and triple superphosphate (TS) and their contribution to improving maize yield and P accumulation in grains. The B70 was outstanding in solubilizing RP and phytate mineralization and more stable in carriers and storage conditions than B32. However, root adherence was more noticeable in B32. Among carriers, AC was the most effective for preserving viable cell counts, closely similar to those of the initial inoculum of both strains. Maize productivity using the mixture RPTS was similar for B70 and B32. The best combination was B70 with RP, which improved the maize yield (6532 kg ha-1) and P accumulation in grains (15.95 kg ha-1). Our results indicated that the inoculant formulation with AC carrier and B70 is a feasible strategy for improving phosphorus mobilization in the soil and maize productivity.

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In this study, the metabolic adjustments performed by maize (Zea mays L.) seminal roots exposed to 25 µM Cd2+ or 25 µM Cu2+ at pre-emergence are compared, focusing on the proteomic changes after metal exposure. Root width was increased, and root length was decreased after 72 h of metal treatment. Both metals induced H2O2 accumulation and lipid peroxidation in the root tip. These changes were accompanied by increases in lipoxygenase activity and 4-hydroxy-2-nonenal content. NMR spectroscopy revealed that the abundance of 38 water-soluble metabolites was significantly modified by Cd and Cu exposure; this set of metabolites comprised carboxylic acids, amino acids, carbohydrates, and unidentified phenolic compounds. Linoleic acid content significantly decreased in Cu-treated samples. The total amount of proteins detected in maize root apexes was 2,171. Gene ontology enrichment analysis of the differentially accumulated proteins was performed to detect pathways probably affected by metal additions. Both metals altered redox homeostasis, up-regulated oxylipins biosynthetic process, and shifted metabolism towards the oxidative pentose-phosphate in the root apexes. However, the methionine salvage pathway appears as a key metabolic module only under Cd stress. The integrative analysis carried out in this study suggests that most molecular features behind the reprogramming of maize root tips to cope with cadmium and copper toxicity are common, but some are not.

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Abstract Southern corn leaf blight (SCLB) is one of the most important corn leaf diseases. Appropriate management strategies and the use of resistant cultivars allow disease control. Therefore, knowing the aspects related to the pathogen and the response of hosts makes it possible to design efficient strategies for selecting genotypes resistant to this disease. In this sense, the objective was to carry out the Bipolaris maydis isolate characterization, evaluating the pathogenicity in different popcorn lines and the symptoms generated in the host after inoculation. The isolate characterization consisted of the macromorphological evaluation of the colonies and the micromorphological evaluation of the conidia in the PDA medium. An experiment was carried out in a greenhouse to evaluate the pathogenicity of the isolate, using 20 inbred lines of popcorn in a randomized block design with four replicates. Inoculation was carried out by spraying leaves, with a suspension containing 1.0 x 104 conidia.ml-1 of the CF/UENF 501 isolate of B. maydis. An incidence assessment and three assessments of disease symptom severity were performed, with seven days intervals between evaluations. The morphological characterization data of the isolate were analyzed using descriptive statistics, and for disease severity, the linear regression model was applied the first-degree model. The variance analysis was performed for the linear and angular coefficients obtained for each treatment. When a difference was found, the Scott-Knott clustering algorithm at 5% significance was applied. The isolate had gray-green colonies, a cottony appearance, and an irregular shape. The lines L353, L354, and L624 show more resistance at the beginning and throughout the evaluations. The high virulence of the CF/UENF 501 isolate made it possible to differentiate the lines in terms of disease intensity and the pattern of symptoms presented.

Resumo Mancha-de-Bipolaris é uma das mais importantes doenças foliares do milho. Estratégias de manejo adequadas e o uso de cultivar resistente permitem o controle da doença, mas para tanto, conhecer os aspectos associados ao patógeno e a resposta do hospedeiro é necessário para traçar estratégias eficientes para seleção de genótipos resistentes a essa doença. Neste sentido, objetivou-se realizar a caracterização do isolado de Bipolaris maydis avaliando a patogenicidade em diferentes linhagens de milho-pipoca e os sintomas gerados no hospedeiro a partir da inoculação. A caracterização do isolado consistiu na avaliação macromorfológica das colônias e micromofológica dos conídios em meio nutritivo BDA. Para avaliação da patogenicidade do isolado foi conduzido um experimento em casa de vegetação utilizando 20 linhagens endogâmicas de milho-pipoca, com delineamento em blocos casualizados, com quatro repetições. A inoculação foi realizada por meio de pulverização em folhas, com uma suspensão contendo 1,0 x 104 conídios.ml-1 do isolado CF/UENF 501 de B. maydis. Foi realizada uma avaliação de incidência e três avaliações de severidade dos sintomas da doença, com o intervalo de sete dias para cada avaliação. Os dados da caracterização morfológica do isolado foram analisados por meio da estatística descritiva e para severidade da doença foi aplicado o modelo de regressão linear de primeiro grau. Realizou-se a análise de variância para o coeficiente linear e angular obtido para cada tratamento e quando constatada diferença aplicou-se o agrupamento de médias de Scott-knott a 5% de significância. O isolado apresentou colônias com coloração cinza esverdeado, aspecto algodonoso e forma irregular. As linhagens L353 e L354 e L624 estão entre as linhagens que apresentaram maior resistência no inicio e ao longo das avaliações. A elevada virulência do isolado CF/UENF 501 possibilitou diferenciar as linhagens quanto a intensidade da doença, bem como o padrão dos sintomas apresentados.

RESUMO

Endophytic bacteria play a crucial role in plant development and adaptation, and the knowledge of how endophytic bacteria assemblage is influenced by cultivation site and plant genotype is an important step to achieve microbiome manipulation. This work aimed to study the roots and stems of endophytic bacteriome of four maize genotypes cultivated in two regions of the semi-arid region of Pernambuco - Brazil. Our hypothesis is that the endophytic community assemblage will be influenced by plant genotypes and cultivation region. Metabarcoding sequencing data revealed significant differences in alfa diversity in function of both factors, genotypes, and maize organs. Beta diversity analysis showed that the bacterial communities differ mainly in function of the plant organ. The most abundant genera found in the samples were Leifsonia, Bacillus, Klebsiella, Streptomyces, and Bradyrhizobium. To understand ecological interactions within each compartment, we constructed co-occurrence network for each organ. This analysis revealed important differences in network structure and complexity and suggested that Leifsonia (the main genera found) had distinct ecological roles depending on the plant organ. Our data showed that root endophytic maize bacteria would be influenced by cultivation site, but not by genotype. We believe that, collectively, our data not only characterize the bacteriome associated with this plant and how different factors shape it, but also increase the knowledge to select potential bacteria for bioinoculant production.

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Southern corn leaf blight (SCLB) is one of the most important corn leaf diseases. Appropriate management strategies and the use of resistant cultivars allow disease control. Therefore, knowing the aspects related to the pathogen and the response of hosts makes it possible to design efficient strategies for selecting genotypes resistant to this disease. In this sense, the objective was to carry out the Bipolaris maydis isolate characterization, evaluating the pathogenicity in different popcorn lines and the symptoms generated in the host after inoculation. The isolate characterization consisted of the macromorphological evaluation of the colonies and the micromorphological evaluation of the conidia in the PDA medium. An experiment was carried out in a greenhouse to evaluate the pathogenicity of the isolate, using 20 inbred lines of popcorn in a randomized block design with four replicates. Inoculation was carried out by spraying leaves, with a suspension containing 1.0 x 104 conidia.ml-1 of the CF/UENF 501 isolate of B. maydis. An incidence assessment and three assessments of disease symptom severity were performed, with seven days intervals between evaluations. The morphological characterization data of the isolate were analyzed using descriptive statistics, and for disease severity, the linear regression model was applied the first-degree model. The variance analysis was performed for the linear and angular coefficients obtained for each treatment. When a difference was found, the Scott-Knott clustering algorithm at 5% significance was applied. The isolate had gray-green colonies, a cottony appearance, and an irregular shape. The lines L353, L354, and L624 show more resistance at the beginning and throughout the evaluations. The high virulence of the CF/UENF 501 isolate made it possible to differentiate the lines in terms of disease intensity and the pattern of symptoms presented.

Mancha-de-Bipolaris é uma das mais importantes doenças foliares do milho. Estratégias de manejo adequadas e o uso de cultivar resistente permitem o controle da doença, mas para tanto, conhecer os aspectos associados ao patógeno e a resposta do hospedeiro é necessário para traçar estratégias eficientes para seleção de genótipos resistentes a essa doença. Neste sentido, objetivou-se realizar a caracterização do isolado de Bipolaris maydis avaliando a patogenicidade em diferentes linhagens de milho-pipoca e os sintomas gerados no hospedeiro a partir da inoculação. A caracterização do isolado consistiu na avaliação macromorfológica das colônias e micromofológica dos conídios em meio nutritivo BDA. Para avaliação da patogenicidade do isolado foi conduzido um experimento em casa de vegetação utilizando 20 linhagens endogâmicas de milho-pipoca, com delineamento em blocos casualizados, com quatro repetições. A inoculação foi realizada por meio de pulverização em folhas, com uma suspensão contendo 1,0 x 104 conídios.ml-1 do isolado CF/UENF 501 de B. maydis. Foi realizada uma avaliação de incidência e três avaliações de severidade dos sintomas da doença, com o intervalo de sete dias para cada avaliação. Os dados da caracterização morfológica do isolado foram analisados por meio da estatística descritiva e para severidade da doença foi aplicado o modelo de regressão linear de primeiro grau. Realizou-se a análise de variância para o coeficiente linear e angular obtido para cada tratamento e quando constatada diferença aplicou-se o agrupamento de médias de Scott-knott a 5% de significância. O isolado apresentou colônias com coloração cinza esverdeado, aspecto algodonoso e forma irregular. As linhagens L353 e L354 e L624 estão entre as linhagens que apresentaram maior resistência no inicio e ao longo das avaliações. A elevada virulência do isolado CF/UENF 501 possibilitou diferenciar as linhagens quanto a intensidade da doença, bem como o padrão dos sintomas apresentados.

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The development of hybrid plants can increase the production and quality of blue corn, and, thus, satisfy its high demand. For this development, it is essential to understand the heterotic relationships of the germplasm. The objectives of this study were to determine the effects of general (GCA) and specific (SCA) combining ability, as well as the reciprocal effects (REs) on the yields of 10 blue corn lines, and to select the outstanding lines. Diallel crosses were generated with 10 lines and evaluated at the Valle de México Experimental Station in Chapingo, Mexico, and Calpulalpan, Tlaxcala, Mexico. There were differences (p ≤ 0.01) in the hybrids, Loc, effects of GCA, SCA, and REs, and in the following interactions: hybrids × Loc, GCA × Loc, SCA × Loc, and RE × Loc. For GCA, lines Ll, L4, L6, and L9 stood out, with significant values of 3.4, 2.9, 2.9, and 3.1, respectively. For SCA, the hybrids featured were L4 × L10, L2 × L10, L1 × L10, L7 × L8, and L2 × L6, with values of 3.0, 2.5, 2.3, 2.3, and 2.2, and yields of 11.2, 10.2, 10.4, 10.4, and 10.5 t ha-l, respectively. There were no significant REs in these lines. Considerable effects of GCA and SCA were detected; therefore, we concluded that native populations had favorable dominance and additive genetic effects that could be used to support the development of high-yielding lines and hybrids.

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Low rainfall rates are becoming increasingly frequent because of climate change, causing droughts and threatening world food security. For popcorn, drought is the most limiting abiotic factor for plant's growth and development. Thus, the water deficit directly impacts for crop productivity. Based on knowledge of the genetic basis of traits involved in stages of popcorn germination and seedling development under water stress, genotypes with potential for adaptation to adverse growing conditions can be selected early. Therefore, data on genetic effects and combining ability of 10 popcorn parents were compiled to propose breeding strategies for the development of cultivars with greater adaptation to water stress in the early stages. Forty-five diallel hybrids were evaluated under two different water regimes, that is, water stress and full irrigation. This corresponded to a water retention capacity of 25% and 70% of the germination paper. The plants were watered daily as needed for seven days. A range of factors were evaluated, that is, germination traits including the germination speed index and germination on the seventh day; shoot traits including length and dry weight; and root system including length, dry weight, root-to-shoot ratio, maximum root number, root network area, specific and root network length, and root volume. Breeding for drought adaption in the early stages of popcorn development can be successful when hybrids are used, because of the genetic effects of dominance (ϕs). These control the traits evaluated at the seedling stage. The combinations L61 x P2 and L71 x P3 were recommended, in view of the more successful performance estimated for traits related to the shoot and root system.

RESUMO

For popcorn, obtaining and identifying haploids are still challenging steps. We aimed to induce and screen haploids in popcorn using the Navajo phenotype, seedling vigor, and ploidy level. We used the Krasnodar Haploid Inducer (KHI) in crosses with 20 popcorn source germplasms and five maize controls. The field trial design was completely randomized, with three replications. We assessed the efficacy of induction and identification of haploids based on the haploidy induction rate (HIR) and false positive and negative rates (FPR and FNR). Additionally, we also measured the penetrance of the Navajo marker gene (R1-nj). All putative haploids classified by the R1-nj were germinated together with a diploid sample and evaluated for false positives and negatives based on vigor. Seedlings from 14 females were submitted to flow cytometry to determine the ploidy level. The HIR and penetrance were analyzed by fitting a generalized linear model with a logit link function. The HIR of the KHI, adjusted by cytometry, ranged from 0.0 to 1.2%, with a mean of 0.34%. The average FPR from screening based on the Navajo phenotype was 26.2% and 76.4% for vigor and ploidy, respectively. The FNR was zero. The penetrance of R1-nj ranged from 30.8 to 98.6%. The average number of seeds per ear in temperate germplasm (76) was lower than that obtained in tropical germplasm (98). There is an induction of haploids in germplasm of tropical and temperate origin. We recommend the selection of haploids associated with the Navajo phenotype with a direct method of confirming the ploidy level, such as flow cytometry. We also show that haploid screening based on Navajo phenotype and seedling vigor reduces misclassification. The origin and genetic background of the source germplasm influence the R1-nj penetrance. Because the known inducers are maize, developing doubled haploid technology for popcorn hybrid breeding requires overcoming unilateral cross-incompatibility.

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Corn grains are a major source of both the bioactive carotenoids zeaxanthin and lutein. Current methods to quantify these substances have some disadvantages related to sustainability and sample throughput. This work aimed to develop a green, efficient, rapid, and reproducible analytical method to quantify these xanthophylls in corn grains. Solvents recommended by the CHEM21 solvent selection guide were screened. The extraction by dynamic maceration and separation by ultra-high-performance liquid chromatography were optimized by design of experiments. Then, the entire analytical procedure was validated and compared with procedures used for the same purpose, including an official one, and applied to different corn samples. The proposed method was demonstrated to be greener, equal to or more efficient, faster, and more reproducible than the comparative methods. The extraction step could be scaled up for industrial production of zeaxanthin- and lutein-enriched extracts, as it uses only compatible food grade ethanol and water.

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Colombian purple corn Zea mays L. by-products have been chemically characterized. To achieve this, after Amberlite XAD-7 purification and Sephadex LH-20 fractionation, the accurate anthocyanin and flavonol profile using UHPL-DAD-ESI-MS, total monomeric anthocyanin (TMA), polyphenols using Folin-Ciocalteau reduction capacity (FCRC), and antioxidant activity (DPPH and TEAC) of each fraction were performed. Cob and leaves illustrated a more complete flavonoid profile and a higher content of anthocyanins and flavonols, strongly related to the highest reducing power and radical scavenging activity compared to grains. Furthermore, the most antioxidant fractions corresponded to the higher molecular weight compounds. The cob and leaves were enriched in cyanidin-3-O-glucoside, cyanidin-3-O-malonyl-hexoside, and peonidin-3-O-glucoside, peonidin-3-O-(6''-malonyl-glucoside). The purification and fractionation allowed us to establish the chemical and antioxidant characterization, and the resulting revalorization, of purple corn by-products for the first time, and to have available pure fractions of Zea mays L. for a wide diversity of industries.

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The association with Azospirillum brasilense promotes better growth and development in corn plants due to biological N fixation, the capacity to help in the synthesis of phytohormones and to improve the use of nutrients by crop plants. However, there aren't specific recommendations for the use of inoculation in baby corn crop. Thus, this study aimed to evaluate the effects of seed inoculation with A. brasilense, associated with nitrogen fertilization management, on the agronomic performance and chemical quality of baby corn grown in three summer growing seasons (2014/2015; 2015/2016 and 2016/2017). The evaluated treatments consisted of combination of five levels of seed inoculation (0.0, 50, 100, 150 and 200 mL 60,000 seeds-1) based on Azospirillum brasilense, two levels of nitrogen fertilization at sowing time (0.0 and 30.0 kg of N ha-1) and two levels of nitrogen in topdressing (0.0 and 110.0 kg of N ha-1), applied at the V4 stage of the popcorn hybrid IAC 125. The characteristics evaluated were: leaf area index (LAI), leaf nitrogen content (LNC), total husked spikelets yield (HSY) and commercial spikelets yield (CSY), and the chemical characteristics of the commercial spikelets: crude protein content (CPC), starch content (STC) and total sugar content (TSC). The inoculation, when combined with nitrogen fertilization, provided positive responses for LAI and provided an average increment of 6 kg ha-1 to CSY for every 10 mL 60,000 seeds-1 of inoculant added to the seeds. The LNC, CPC, STC and TSC weren't affected by seed inoculation. Nitrogen fertilization provided increments for all characteristics evaluated, except for TSC, which was negatively affected by nitrogen topdressing. The baby corn crop responded positively to seed inoculation with Azospirillum brasilense, combined with Nitrogen fertilization.

RESUMO

Tropical legumes are used to prepare mixed silages to enrich the crude protein (CP) content. In This context, objective of this study was to evaluate the dynamics of fermentation and quality of maize silage with different levels of Pigeon pea. The experimental design was entirely randomized, with four repetitions. The treatments comprised maize silages with six levels of added Pigeon pea (0, 20, 40, 60, 80, and 100%), calculated based on natural matter. The maize hybrid and Pigeon pea varieties used were B 2800 PWU and Cajanus cajan cv. BRS Mandarin, respectively. For the silage, the maize and Pigeon pea were harvested when they reached 335.7 g kg-1 dry matter (DM) and 281.3 g kg-1 DM, respectively. The results revealed that the added of up to 40% Pigeon pea in maize silages promote nutritive increment without compromising their fermentative profile of the silage. Exclusive Pigeon pea silage (100%) undergoes fermentative losses that compromise the silage quality. Therefore, mixed silages of maize with Pigeon pea, with appropriate levels of addition, are a viable alternative to increase the nutritive value of silages, mainly the CP content, contributing to reducing the cost of acquisition of protein salts.

As leguminosas tropicais têm sido utilizadas para a confecção de silagens mistas para enriquecer os teores de proteína bruta (PB). Neste contexto, o objetivo deste estudo foi avaliar a dinâmica da fermentação e qualidade da silagem de milho com níveis de feijão guandu. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Os tratamentos foram constituídos da silagem de milho com seis níveis de feijão guandu (0; 20; 40; 60, 80 e 100%), calculado com base na matéria natural. O híbrido de milho e a variedade de feijão guandu utilizados foram o B 2800 PWU e o Cajanus cajan cv. BRS Mandarim, respectivamente. Para a ensilagem, o milho e o feijão guandu foram colhidos quando atingiram 335,7 g kg-1 de MS (matéria seca) e 281,3 g kg-1 MS, respectivamente. Os resultados mostraram que a adição de até 40% de feijão guandu na ensilagens de milho promove incremento nutritivo sem comprometer o seu perfil fermentativo da silagem. Silagem exclusiva de feijão guandu apresenta perdas fermentativas que compromete a qualidade da silagem. Portanto, silagens mistas de milho com feijão guandu, combinadas com níveis adequados de adição, torna-se alternativa viável para incrementar o valor nutritivo da silagem, principalmente os teores de PB, contribuindo com redução do custo com aquisição de sais proteínados.

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RESUMO

Tropical legumes are used to prepare mixed silages to enrich the crude protein (CP) content. In This context, objective of this study was to evaluate the dynamics of fermentation and quality of maize silage with different levels of Pigeon pea. The experimental design was entirely randomized, with four repetitions. The treatments comprised maize silages with six levels of added Pigeon pea (0, 20, 40, 60, 80, and 100%), calculated based on natural matter. The maize hybrid and Pigeon pea varieties used were B 2800 PWU and Cajanus cajan cv. BRS Mandarin, respectively. For the silage, the maize and Pigeon pea were harvested when they reached 335.7 g kg-1 dry matter (DM) and 281.3 g kg-1 DM, respectively. The results revealed that the added of up to 40% Pigeon pea in maize silages promote nutritive increment without compromising their fermentative profile of the silage. Exclusive Pigeon pea silage (100%) undergoes fermentative losses that compromise the silage quality. Therefore, mixed silages of maize with Pigeon pea, with appropriate levels of addition, are a viable alternative to increase the nutritive value of silages, mainly the CP content, contributing to reducing the cost of acquisition of protein salts.(AU)

As leguminosas tropicais têm sido utilizadas para a confecção de silagens mistas para enriquecer os teores de proteína bruta (PB). Neste contexto, o objetivo deste estudo foi avaliar a dinâmica da fermentação e qualidade da silagem de milho com níveis de feijão guandu. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Os tratamentos foram constituídos da silagem de milho com seis níveis de feijão guandu (0; 20; 40; 60, 80 e 100%), calculado com base na matéria natural. O híbrido de milho e a variedade de feijão guandu utilizados foram o B 2800 PWU e o Cajanus cajan cv. BRS Mandarim, respectivamente. Para a ensilagem, o milho e o feijão guandu foram colhidos quando atingiram 335,7 g kg-1 de MS (matéria seca) e 281,3 g kg-1 MS, respectivamente. Os resultados mostraram que a adição de até 40% de feijão guandu na ensilagens de milho promove incremento nutritivo sem comprometer o seu perfil fermentativo da silagem. Silagem exclusiva de feijão guandu apresenta perdas fermentativas que compromete a qualidade da silagem. Portanto, silagens mistas de milho com feijão guandu, combinadas com níveis adequados de adição, torna-se alternativa viável para incrementar o valor nutritivo da silagem, principalmente os teores de PB, contribuindo com redução do custo com aquisição de sais proteínados.(AU)

Assuntos