Search

This study investigated the effect of gaseous ozone (O3) on the chemical and microbiological properties of whole-plant corn silage. Conducted on a commercial dairy farm in Brazil, maize was ensiled in experimental bag silos and treated with varying levels of O3 (0%, 1.25%, 3.12%, 4.15%, and 6.25%). The findings revealed minimal nutrient losses in starch, non-fiber carbohydrates, crude protein, and total digestible nutrients compared to untreated fresh maize. O3-treated silages exhibited increased levels of ash, ether extract, calcium, and phosphorus. Notably, the application of 3.12% to 4.15% O3 improved microbiological characteristics, significantly reducing mold and yeast populations, which are common issues in farm-produced silage. This study demonstrated that gaseous ozone is a promising additive for enhancing the microbiological quality of corn silage, offering an effective alternative to traditional chemical preservatives. [ABSTRACT FROM AUTHOR]

Context: The productivity of crops is influenced by the available net water balance, which relies on a complex interplay of edaphic and climatic factors. In this sense, rainfall is the leading water input for crop growth and yield, especially in water-scarce regions under semi-arid climates worldwide. Aims: This study aimed to define the optimum cropping calendar and the agroclimatic and agroecological zones for rainfed maize in the state of Ceará, which is predominantly located within the Brazilian semi-arid region, assuming different rainfall scenarios. Methods: We considered the subdivision of the study area into eight homogeneous precipitation regions according to the regional rainfall pattern. The climatic water balance for each region over two decades was calculated from historical weather data series, assuming three rainy scenarios: dry, regular, and rainy. The agroclimatic zoning was defined through the crop water balance results, soil classification, land use and occupation, slope and temperature, weighted through a multi-criteria decision analysis based on the Analytic Hierarchy Process. Key results: The recommended planting period was broader in rainy conditions. However, there may be some dry spells between two 10-day intervals of the calendar, which impair plant growth depending on their intensity. For the dry scenario, the agroclimatic zoning showed that the marginal water deficiency covered 96.55% of the study area. Conclusions: Rainfed maize cultivated under the semi-arid climate of Ceará state is viable in rainy conditions, partially restricted in regular years, and not recommended in dry years. Implications: This study emphasises the importance of climate monitoring in effective planning for rainfed maize cultivation in semi-arid regions. This study aimed to define the optimum cropping calendar and the agroclimatic and agroecological zones for rainfed maize (Zea mays L.) across Ceará state, situated within the Brazilian semi-arid region, assuming different rainfall scenarios: dry, regular, and rainy. The agroclimatic zoning was defined trough the crop water balance results. Our findings demonstrated that rainfed maize cultivated under the semi-arid climate of Ceará state is viable in rainy conditions, partially restricted in regular years, and not recommended in dry years. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the absorption, partitioning, and redistribution of nutrients by phenological stage of the maize crop, under the edaphoclimatic conditions of the municipality of Brejo, Maranh~ao, Brazil. The experiment was carried out in a Yellow Argisol, under a randomized block design, with seven treatments corresponding to the phenological stages V5, V8, VT, R1, R3, R5, and R6, and four replicates. The plant was partitioned into leaves, stalk, reproductive organs (tassel, straw, cob), and grains to determine the concentrations of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn. The accumulation of nutrients in each organ in the different phenological stages was estimated based on the values of dry weight and nutrient concentrations. A slow accumulation of dry weight was observed in the maize plant until the flowering stage (VT), a pattern also observed for the nutrients P, Mg, S, and Cu. Nutrients N, K, Ca, B, Fe, Mn, and Zn showed values close or superior to 50% of the maximum accumulated up to VT. The decreasing order of nutrient accumulation was N>K>P>Mg> S>Ca>Fe>Zn>Mn>Cu>B. The nutrients with the highest harvest rates were P>N>Mg>S>Zn (0.84, 0.74, 0.72, 0.69, and 0.51, respectively). N, K, Ca, B, Zn, Fe, and Mn are the most absorbed nutrients in the initial stage of crop development. The nutrients that are absorbed in greater quantity after flowering are P, S, Mg, and Cu. The degrees day sum showed no effects on the maize crop cycle under the edafoclimatic conditions of this study. [ABSTRACT FROM AUTHOR]

Although nitrogen is the nutrient most required by maize, doses of N lower than those recommended are applied to maize grown in semiarid environments, which limits the achievement of profitable yields. The objective of this study was to evaluate changes in soil fertility, nutritional status and dry matter production of maize plants fertilized with organic and mineral fertilizers in a semiarid region. A factorial experiment was carried out in Sobral, Ceará state, Brazil, in a randomized block design. The factors were two N sources (organic compost and urea), and four N rates: 27.5, 55, 110 and 165 kg ha−1, with three replications. We assessed variables associated with soil fertility, plant nutritional status, chlorophyll content, grain yield and total dry matter production. The highest rates of organic compost resulted in the highest levels of P (17.7 mg dm−3) and K (102.2 mg dm−3) in soil when compared to the control (7.7 and 69.0 mg dm−3, respectively). However, organic compost rates below 110 kg ha−1 of N-equivalent fertilizer were not enough to supply the plants' demand for P and K. Low N rates promoted a decrease in soil inorganic N in the second year of application. Applying urea to maize plants led to greater dry matter production than organic compost in the second consecutive crop season. The use of organic compost at rates lower than 110 kg ha−1 of N-equivalent fertilizer decreases soil fertility and has no impact on maize dry matter production. [ABSTRACT FROM AUTHOR]

Maize is a versatile crop, which allows from the production of whole plant silage to the harvest of grain maize, but it is necessary to verify the genotypes with these potentials according to the region of cultivation. Thus, the objective of this work was to identify the aptitude of maize for biomass for silage and grain in two years of second season cultivation in Dourados-MS. The experiment was conducted at Embrapa Western Agriculture, Dourados, MS, Brazil under field conditions in the experimental design was in randomized complete block in a 6x2 factorial scheme be six maize genotypes (BRS1010, KWS9606, BRS3046, 1P2224, 1Q2383, CAPO) and two growing years (2021 and 2022) with five replications. The agronomic traits of plant biomass for silage (plant and ear heigh, stem diameter number of leaves, green mass yield plant, leaf, steam more tassel and ear, dry matter yield in the plant and efficiency of land) and maize grain (ear diameter ear length, number of grain rows per ear, number of grains per row in ears, hundred seed weight and grain yield) were evaluated. There was an increase in the values of the traits for whole maize plant in the year 2022 compared to the year 2021. The maize genotypes indicated for biomass for silage were BRS3046, KWS9606 and 1Q2383, as for maize grain, the experimental genotypes that are under development, 1P2224 and 1Q2383, are promising options for the region. [ABSTRACT FROM AUTHOR]

Bacterial leaf streak (BLS) of maize (Zea mays), caused by the bacterium Xanthomonas vasicola pv. vasculorum (Xvv), was first reported in Brazil in 2018. In this study, we evaluated 52 species of cultivated plants, cover crops, forage, and grasses that are used in succession or crop rotation with maize, and weeds with natural occurrence in maize-producing regions, to determine their potentials as alternative hosts for Xvv. We investigated (i) the pathogenicity of Xvv based on symptom development, (ii) epiphytic colonization of the bacterium in asymptomatic plants, and (iii) bacterial colonization in plant tissues using scanning electron microscopy (SEM) in symptomatic and asymptomatic species. Ten species, all belonging to the Poaceae family, presented symptoms after Xvv infection, including Avena sativa (cvs. IPR Afrodite and IPR Esmeralda), A. strigosa (cv. IPR 161), Hordeum vulgare (cv. BRS Cauê), Oryza sativa (cv. IPR 117), Brachiaria brizantha (Brizantha and cv. Marandu), Digitaria horizontalis, D. insularis, Echinochloa colonum, Eleusine indica, and Sorghum arundinaceum. Furthermore, epiphytic colonization by Xvv was observed in 23 asymptomatic species. Scanning micrographs revealed that Xvv cells and their aggregates were distributed throughout the leaf surface. In addition, bacterial colonization in the intercellular tissues of the substomatal chambers of white oat, black oat, and maize was observed across the tissue fractures. Despite showing typical symptoms of Xvv infection, SEM examination revealed evidence of Xvv colonization only on the leaf surface of rice. In asymptomatic species, such as rye, sorghum, and millet, a low number of bacterial cells were found on the leaf surface. However, no evidence of internal tissue colonization was observed in millet fractures, suggesting that Xvv survives only epiphytically in this species. [ABSTRACT FROM AUTHOR]

Plants respond indirectly to herbivore injury in a species‐specific way and emit a specific blend of volatiles that are attractive to the enemies of herbivores. We evaluated whether maize plants, Zea mays L. (Poaceae), can recognize herbivory damage from a generalist stink bug, Diceraeus melacanthus Dallas (Hemiptera: Pentatomidae). This species is not a common pest in maize, but is currently found on maize crops in Brazil. We aimed to answer the following questions: (1) does D. melacanthus use maize plant volatiles for host location? (2) Do maize plant chemical volatile profiles change due to feeding by D. melacanthus? And (3) do herbivore‐induced plant volatiles (HIPVs) emitted by maize plants play a role in the foraging behaviour of the generalist stink bug egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Scelionidae)? The results show that females of D. melacanthus do not use constitutive volatiles or HIPVs as host location cues. However, feeding by D. melacanthus activates maize indirect defence, inducing emission of HIPVs and attracting the herbivore's enemy. Thus, strengthening indirect defence of plants can be a strategy to protect crops in the field by recruiting natural enemies through chemical information, as an additional approach to control D. melacanthus within an integrated pest management program. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell 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.)

In no-tillage systems, soil compaction has caused negative impacts on crop productivity and soil quality. The objective of this study was to evaluate the soil physical quality after different crops of the second season: maize, sorghum, and millet in compacted and uncompacted soils, in addition to evaluating the performance of soybean in succession in Rhodic Ferralsol under no-tillage (NT) in the Brazilian Cerrado biome. A field experiment was conducted during the second season of 2019 and the first season of 2019/20 in Rio Verde, Brazil. The experimental design used randomized blocks in a 3 × 2 factorial scheme, with six replications. The first factor corresponded to the cultivation of maize, sorghum, and millet; the second factor was the cultivation of these crops in compacted and uncompacted soils. The physical properties of the soils in the 0–0.1 and 0.1–0.2 m depth layers were evaluated after the second season of cultivation, in addition to the agronomic characteristics of the soybean cultivated in succession. The results indicate that the compaction influenced the soil physical quality, mainly in the 0.1–0.2 m layer, reflecting a decrease in the performance of the soybean crop (i.e., the plant height, number of pods per plant, and grain yield). The use of the second-season crop of millet improved the soil physical properties of penetration resistance and macroporosity and improved the water/air relation. The use of millet provided a reduction of up to 20% in the soil penetration resistance. About 10% more soybean was produced after cultivation in succession to millet compared to maize and sorghum. [ABSTRACT FROM AUTHOR]

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical 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.)

Direct and indirect injury caused by Dalbulus maidis (Hemiptera: Cicadellidae) in corn is an ever-increasing concern in Brazil and other corn-producing countries of the Americas. This highly efficient vector transmits corn stunting pathogens and is of economic concern in the Neotropics, including temperate regions where epidemic outbreaks are now common. Despite the progress made so far, Brazilian corn growers continue to struggle with this pest and its associated pathosystem. In this review, we gathered relevant and updated information on the bioecology, population dynamics, and damaging potential of D. maidis. Our goal was to better understand its intimate association and complex interactions with the host crop and transmitted pathogens. Based on available scientific literature, we identified factors which explain the recent increase in D. maidis occurrence in South America, including the cultivation of corn during multiple growing seasons, overlapping of susceptible crops, and widespread use of genetically modified hybrids. The reasons for the overall inefficiency of current suppression strategies aimed at this pest are also summarized. Finally, a management program for D. maidis and corn stunt disease is proposed, combining strategies such as eradicating volunteer corn, reducing the planting period, using tolerant hybrids, and applying chemical and/or fungal insecticides. Prospects regarding the pest's status are also outlined. Overall, the information presented here will serve as a decision-making guide within Brazilian and South American corn production systems, as well as paving the way for devising novel strategies aimed at suppressing D. maidis populations and limiting the spread of corn stunt disease. [ABSTRACT FROM AUTHOR]

Tillage and cover crops influence soil carbon stocks and nutrient cycling by altering mineralization and nutrient input rates. This study aimed to assess the effects of different tillage systems and winter cover crops on soil carbon stock and maize yield in Southern Brazil. Three tillage treatments were compared: conventional tillage (CT), reduced tillage (RT), and no-tillage (NT). The winter cover crops were: common vetch (Vicia sativa L.), fodder radish (Raphanus sativus L.), and black oat (Avena strigosa L.). Soil sampling was performed 4.5 years after the beginning of the experiment. Samples were taken through the excavation method (0–45 cm depth) and evaluated for organic carbon content and bulk density. NT plots had the highest carbon stock (80.22 ± 0.77 Mg ha−1), regardless of the cover crop. The lowest carbon stock (61.09 ± 0.69 Mg ha−1) was recorded on CT soil under common vetch. Vetch increased maize yield in CT and RT treatments by 10–38% and 26–34%, respectively, but its lower dry matter production and C input led to reduced soil carbon stocks compared with fodder radish and black oat. Our results confirm that soil conservation practices such as NT combined with the use of high input and quality cover crops promote environmental and agronomic benefits, increasing soil carbon stock and maize yield. • The impact of tillage systems and cover crops on soil C and maize yield was measured. • Common vetch increased maize yield by 38% in conventional tillage system but reduced soil C. • No tillage, regardless of cover crop, resulted in higher C stocks than conventional or minimal tillage. • Climate regulation and food production are enhanced by no-tillage and cover crops. [ABSTRACT FROM AUTHOR]

The production of green maize is considerable important for various regions of Brazil. It is vital that breeding programs of public institutions seek to meet the needs of this market sector, which has a relevant social role, mainly on small properties. The aim of this study was to estimate the inbreeding depression and the genetic components (m + a and d) of characters associated with green maize production and quality in three populations of different genetic basis: the variety UFG-Samambaia (P1), and two populations formed by crossing the commercial hybrids (P2 e P3). The S1 progenies of each population, the three S0 populations, and two checks were evaluated in a 14 × 14 triple lattice design. Agronomic and ear quality traits were evaluated. Genetic variability and greater inbreeding depression were observed for most of the traits among the P1 progenies. In P2 and P3, greater inbreeding depression was observed for male flowering, ear weight without straw, ear diameter, ear weight, female flowering, breakage and lodging, and grain color. The traits of ear quality, important for green maize production, had greater inbreeding depression than the agronomic traits, indicating that inbreeding depression and exploitation of heterosis should be considered in the selection process for these traits. [ABSTRACT FROM AUTHOR]

Native genetic resistance is an effective and environmental-friendly alternative to control fungal infections and reduce fumonisin content in maize kernels. Marker-assisted selection can accelerate the genetic gains over breeding cycles. This study aimed to identify genomic regions and candidate genes associated to fumonisin contamination in a panel of tropical maize elite lines. A total of 205 inbred lines were grown under field conditions in Brazil to measure the fumonisin content in grains. The lines were genotyped by sequencing, generating 385,654 high-quality polymorphic single-nucleotide polymorphisms (SNPs). The Genome Wide Association Study (GWAS) identified 40 SNPs located on 19 genomic regions associated to the fumonisin contamination, of which seven were coincident with other studies. Six candidate genes localized within these QTL regions shared functions related with pathogen resistance, six shared functions related with pathogen resistance, including one associated with Fusarium ear rot also identified at bin 10.03 in a previous study. Tropical maize lines resistant to fumonisin contamination were at low frequency in the Embrapa's panel, but most of the resistant lines shared more than 73% of the resistance alleles at SNP loci associated with the trait. Thus, favorable alleles could be potentially used to improve resistance to fumonisin contamination in maize. [ABSTRACT FROM AUTHOR]

Crop growth models are abstract tools that represent a real system, being a simple and important technology to develop studies aiming to improve the yields of the most agricultural crops, like the maize in Brazil. The objective of this study was to analyze the sensitivity of the main AquaCrop model input parameters, as well as their responses in maize yield estimation, in State of Paraná, Southern Brazil. The analyses were performed with the genotype 30R50YH, 2014/15 planted on April 11, 2014. The parameters analyzed refer to crop, soil and soil management. The parameters were modified individually, maintaining the others fixed. With the results, the sensitivity index (SI) was calculated, which allowed the identification of the most sensitive AquaCrop parameters. The parameters related to the crop showed a higher sensitivity, as they were associated with the main equations of the model. The parameters related to the harvest index (HIo ), saturated hydraulic conductivity (KSAT), soil water stress (Ks) and air temperature stress (ATS) did not present sensitivity in the model for the conditions evaluated. According to the SI, the crop coefficient with complete canopy expansion (KcTR,x) was the most sensitive parameter in the model (SI = 1.0777), as it directly affected the maize biomass production and yield formation. [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 African planthopper Leptodelphax maculigera (Hemiptera: Delphacidae) has been recently reported in many places in Brazil in association with maize. Its occurrence in maize production fields in Brazil has brought concerns to the corn production chain regarding the possibility of this planthopper to be a vector for maize bushy stunt phytoplasma (MBSP), corn stunt spiroplasma ( Spiroplasma kunkelii ), maize rayado fino virus (MRFV), and maize striate mosaic virus (MSMV). The phytoplasma and spiroplasma, which are bacteria belonging to the class Mollicutes, and the two viruses are associated with the corn stunt disease complex. Given the presence of the African planthopper species and the corn stunt complex in Brazil, we further investigated the abundance of this planthopper species in the State of Santa Catarina, Brazil, and whether the planthopper can carry the four pathogens. We inspected 12 maize production fields in different municipalities in the state for 20 weeks, using two yellow sticky traps for each maize field. The sticky traps were replaced weekly. A total of 130 specimens of L. maculigera were captured, with a great discrepancy in quantity among locations and weeks. We detected the mollicute MBSP and the viruses MRFV and MSMV in L. maculigera , whereas S. kunkelii was absent in the assessed African planthopper samples. The molecular detection of the phytoplasma and the viruses in field-collected African planthoppers is strong evidence that this insect species has the ability to acquire those pathogens through feeding from the phloem of diseased maize plants. Nonetheless, transmission capacity needs to be experimentally proven to assert L. maculigera as a vector for the corn-stunting pathogens., Competing Interests: The author(s) declare no conflict of interest.

Plant growth-promoting endophytic microorganisms in agriculture have been expanding in Brazil and are an excellent strategy to face the challenges of current agriculture, such as reducing production costs with fewer environmental impacts, without detriment to productivity. However, little is known about the factors that can affect the colonization of endophytic such as inoculant concentration and mineral fertilization. The present study aimed to evaluate the influence of these factors on soybean and maize crops and found that for soybean crops, the highest Bacillus subtilis concentration of 1 x 104 and 1 x 1010 CFU ml-1 promoted the highest number of recovered bacteria, when there was no mineral fertilization. However, mineral fertilization limited the number of recovered bacteria, suggesting that mineral fertilization interferes with endophytic colonization. For maize crops, the highest number of recovered bacteria occurred from the concentration of 1 x 106 CFU ml-1, not differing from the highest concentrations. A mineral fertilization dose of 25% promoted the greatest B. subtilis recovery compared to the other treatments. Regarding plant development, the highest microbial inoculum concentrations did not necessarily promote greater positive growth promotion effects compared to the concentration of 1 x 104 CFU ml-1 for both crops. The results also suggest that the higher number of endophytic bacteria recovered in the plant does not necessarily affect plant growth in the same proportion. For soybean plants, there is a strong tendency that with the increase in the B. subtilis inoculant concentration, the need for mineral fertilization doses to achieve the same plant development is consequently increased, and inoculations with 1 x 105 and 1 x 106 CFU ml-1 with fertilization doses between 44% and 62% are the ideal combinations for greater plant development. In maize plants, the best growth promotion response (height) was obtained using inoculation concentration of 1 x 10² and 1 x 1010 CFU ml-1, increasing according to the increase in fertilization doses. The findings suggest, for soybean crop, that these high inoculum concentrations required more photosynthetic metabolites from the plants and more nutrients from the soil. Thus, the need for mineral fertilization for plant growth must be increased. [ABSTRACT FROM AUTHOR]

Forage grasses cultivation in production system with soybean and maize is an alternative to improve tropical weathered soils quality in Brazil. The aim of the study was to evaluate the effects in the production systems involving cultivation of Urochloa brizantha cv. Piatã, in monoculture or in succession with soybean and maize crops, on organic matter and structuring of soil in Brazilian savanna. The experiment was implemented in the 2010/2011 season. The treatments consisted of nine production systems and a native forest (savanna) as a reference area. In March 2017, soil sampling was carried out for C and N analysis, physical and chemical fractionation of SOM and aggregate stability. Production systems influenced total organic carbon (TOC) and aggregate stability, mainly in the surface layers, leading to changes in SOM quality. TOC was 31% lower in monoculture soybean production system, when compared to native savanna area, in the 0.00–0.20 m layer. The agricultural production systems influence organic matter quality and soil aggregates stability. For the Brazilian savanna conditions, grain cultivation systems under no-tillage that integrate Urochloa brizantha cv. Piatã contribute to the soil quality improvement. Soybean monoculture generally provides worse soil quality indices compared to other agricultural production systems. [ABSTRACT FROM AUTHOR]

The agricultural use of arbuscular mycorrhizal fungi, such as Rhizoglomus intraradices, can increase the efficiency of phosphate fertilization for the benefit of the corn plant and grain nutrition. In this study, a field experiment was conducted in an area of Selvíria/MS, Brazil, in the years 2019 and 2020, to verify the effects of reduced doses of phosphorus combined with the inoculation of corn seed with R. intraradices on corn plant growth and grain nutrient contents. The experiment was laid in a randomized block design in subdivided plots with four repetitions and twenty treatments resulting from combining five doses of P2O5 (0%, 25%, 50%, 75%, and 100% of the recommended dose) with four doses (0, 60, 120, and 180 g ha−1) of an inoculant containing R. intraradices. Leaf and kernel macro- and micronutrient contents were evaluated. The foliar P content in 2020 was a function of the interaction between phosphate fertilization and AMF inoculation, with the highest leaf P content observed at the 100% of P2O5 combined with AMF inoculation between 120 and 140 g ha−1. In the grains Mg content, an interaction was observed between the two factors in 2020 and the response surface, showing that the highest Mg content was obtained when maximum doses of P2O5 and maximum doses of inoculant were combined. A response surface showed that, in 2020, the highest leaf Zn content occurred when 35–55% P2O5 is applied with no inoculation and when P2O5 is limited to 20–30%, and there is inoculation with doses between 90 and 150 g ha−1. Phosphate fertilization increased foliar K (2019) and Mg (2020) contents, with maximum points at doses of 76.57% and 88.80%, respectively. [ABSTRACT FROM AUTHOR]

The exploitation of natural resources for agriculture is growing to fulfill the demand for food, which requires the rational use of inputs for sustainable production. Brazilian agricultural production stands out on the international scene. For instance, corn is one of the most exported products in Brazil, which is possible through the planting in the second crop season within a year, called the "off-season". In addition to being a technique that allows soil conservation, it also reduces the use of inputs and soil tillage. The agricultural production systems require a large amount of energy throughout their processes, mainly through inputs and fuels. Energy flows allow for the identification of the efficiency of the production system and, consequently, its sustainability. Indicators regarding net energy gain per area (Energy balance) and energy profitability (Energy Return on Investment) were applied. The first-season system presented higher energy demand when compared to the second-season system, with a difference of 10.24 GJ ha−1 between the conventional ones and 10.47 GJ ha−1 between the transgenic ones. However, the indicators showed higher energy efficiency in the transgenic off-season corn production, in which the return on energy was 55% higher, and the energy incorporation was 35% lower when compared to conventional first-season corn. [ABSTRACT FROM AUTHOR]

BACKGROUND: Since the last decade, Dalbulus maidis has become the primary pest in cornfields, particularly due to its ability to transmit plant pathogens. Dalbulus maidis is the main vector of the corn stunt spiroplasma and maize bushy stunt phytoplasma. However, there is little information available on this pest. Understanding its spatial dynamics may allow us to determine how its infestations begin and to identify its colonization patterns, dispersal, and the role of landscape structure on D. maidis dynamics. Thus, this study aimed to investigate within‐field spatial distribution and the factors associated with D. maidis abundance in five commercial fields. RESULTS: In all fields, higher infestations occurred at the boundaries of the central pivot, showing a clear edge‐biased distribution. Ranges varied from 100.4 to 611.8 m, and our models' overall fit indicated strong to moderate spatial dependency. Additionally, correlation analyses indicated a positive effect of air temperature on the population of D. maidis. Conversely, rainfall negatively affected D. maidis. CONCLUSION: This study provides essential guidance for improving D. maidis integrated pest management at regional and local scales. Based on its high dispersal ability, our study suggests the need for a legislative or regulatory method of control for D. maidis, especially in regions where corn has more than one growing season. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The use of metabasalt powder in the soil can promote remineralization and increase crop yield. Therefore, this study was conducted with the objective of investigating the residual effect of metabasalt rock powder after one year of application on the agronomic performance of the maize crop. The experimental design used was a randomized block with four application rates of metabasalt powder (0, 3, 6 and 9 tha-1) and six replications. The metabasalt powder used is a residue from an amethyst stone mining company in Rio Grande does Sul, Brazil. At the physiological maturity of the crop, plant height, ear insertion height, ear length, ear diameter, number of grain rows per ear, number of grains per row, thousand grain mass and grain yield of maize were measured. The application of metabasalt powder resulted in increase in the number of grains per row, thousand grain mass and grain yield of the maize crop. The application of 6.0 tha-1 of metabasalt rock powder resulted in the highest maize grain yield. [ABSTRACT FROM AUTHOR]

Simple Summary: The fall armyworm (Lepidoptera: Noctuidae) is one of the main pests of corn and cotton in South American countries, but it can also feed and survive on castor bean. These plants are cultivated in Brazil in an intercropping and/or succession system in small and large rural properties, at different times of the year near to each other, what can facilitate the movement of this pest and make it difficult to control. The results obtained are promising and confirm our hypothesis that the consumption of host crops less suitable for the fall armyworm can impair its development, survival and reproduction, reducing its infestation in the next host. The polyphagy of Spodoptera frugiperda (Lepidoptera: Noctuidae) renders its control difficult because variations in the phenology of host plants grown in different seasons of the year and near each other can facilitate the movement of this pest between crops. The objective of this work was to examine certain biological characteristics of S. frugiperda fed on an artificial diet or on cotton, castor bean, or corn leaves. The experimental design was in randomized blocks, with four treatments represented by S. frugiperda caterpillars fed an artificial diet (T1) or pieces of cotton (T2), castor bean (T3) or corn (T4) leaves with five replications (five caterpillars per replication). The duration and survival of the egg, larva, pre-pupa, pupa and egg-adult period and the reproductive characteristics of this insect were determined. The survival, development and reproduction data of S. frugiperda originated from individuals reared with cotton and castor bean leaves were lower than those fed on corn leaves or an artificial diet. The number of nonviable eggs laid by females originated from caterpillars fed on castor bean leaves was higher than those fed on cotton and corn leaves or an artificial diet. The very higher number of unviable S. frugiperda eggs resulting from castor leaves can reduce outbreaks of this pest in cotton and corn crops after the cultivation of that plant, or by intercropping with this plant, in the main producing regions of Brazil. [ABSTRACT FROM AUTHOR]

Many species in the Fusarium fujikuroi Species Complex (FFSC) have an affinity for grass species, with whom they live in an endophytic association or cause disease. We recovered isolates of Fusarium from agriculturally important grasses in Africa and Brazil, and characterized them with morphological markers, mating type, and Amplified Fragment Length Polymorphisms (AFLPs). We also conducted multi-locus phylogenetic analyses based on partial DNA sequences of translation elongation factor-1α (TEF1), β-tubulin (TUB), and the second largest subunit of RNA polymerase (RPB2) gene regions. Sexual cross fertility was used to test the biological species concept and the sexual stage of F. madaense is described. A novel species within the FFSC, Fusarium mirum , that is different from the other known species in the complex, was formally described. Fusarium mirum , F. madaense , and Fusarium andiyazi are a tightly intertwined species trio that are morphologically identical, but phylogenetically distinguishable, and amongst whom interspecific genetic exchange may still occur. These three species are so close that they cannot be reliably distinguished if only sequences of the TEF1 gene are used. In pathogenicity tests, all tested isolates of F. madaense from sugarcane, sorghum, maize, millet and Brachiaria could induce stalk rot in sorghum, maize and millet, and pokkah boeng in sugarcane. This study increases our understanding of the diversity of species within the FFSC that cause disease in tropical grasses or act as endophytes, and their geographic distributions. The genetically close relationship between F. mirum , F. madaense , and F. andiyazi provides an opportunity to study and identify factors underlying their limited inter-specific cross-fertility and sympatric speciation. • Described a new species, F. mirum , closely related to F. madaense and F. andiyazi • Demonstrated pathogenicity of F. madaense and F. mirum on multiple known hosts • TEF-1 is very highly polymorphic amongst F. mirum , F. madaense and F. andiyazi • Some strains identified as F. andiyazi based on TEF-1 probably are F. madaense [ABSTRACT FROM AUTHOR]

The presence of volunteer corn plants among soybeans, both resistant to glyphosate, has increased in recent years in Brazil. The objective of this study was to quantify the impact on the agronomic performance in RR soybeans by the presence of volunteer RR corn in field conditions. The experiment was conducted in Tiradentes do Sul (RS), 2018/19 harvest. The experimental design used in the experiment was randomized blocks with four replications: control in the clean (only soybean) and eight densities of volunteer corn in soybean crop with 1, 2, 3, 4, 5, 6, 7 and 8 corn plants m-2. In the physiological maturation of soybean, plant height, number of lateral branches, stem diameter, height of insertion of the first pod, number of pods plant-1 and grain yield were evaluated. All variables analyzed were negatively affected by the increase in the density of volunteer corn infestation, where the variables grain yield and number of pods plant-1 were the most affected, 63% and 81%, respectively. The presence of volunteer corn has a high capacity to reduce the yield of soybeans in the proportion of 500 kg ha-1 plant-1 of corn m-2, and even at low densities, it needs control. [ABSTRACT FROM AUTHOR]

The use of organomineral fertilizer can promote increments of organic matter and affect the enzymatic activity of the soil. The objective of this research was to evaluate the effect of organomineral and mineral fertilizer with humic substances on soil organic matter fractions and enzymes activities. The study was set up in a Xanthic Ferrasol, in the Cerrado region, Brazil. Treatments consisted of two fertilizers and four rates of P fertilizer. The following fertilizers were studied: mineral fertilizer enriched with humic substances (03% of N, 25% of P2O5, 08% of K2O, with 1% humic substance); and granulated organomineral produced from poultry litter and mineral fertilizer (MAP – mono-ammonium phosphate, with 26.6% of P2O5 and 18.2% of organic carbon). Five rates of P were also evaluated (0, 20, 40, 60, and 80 kg ha−1 of P2O5). The crop production, soil organic matter fraction and enzymes were assessed in the 2014/2015 and 2015/2016 growing seasons. Contents of the total organic carbon, particulate organic carbon, humic acid, fulvic acid, and maize and soybean grain yield were positively influenced by the fertilizer application. Fertilization treatments did not affect the enzymes activities, but they showed positive correlations with particulate organic carbon. [ABSTRACT FROM AUTHOR]

The cultivation of special corns, such as baby corn, has had a positive influence on the economy of the country. Despite its importance, there is still a need for studies aimed at increasing production and planting areas of the crop. Phytosanitary studies are of particular interest, as the cultivation of such crops is susceptible to a series of pathogens, such as Bipolaris maydis, Exserohilum turcicum, and Puccinia polysora. The use of resistant cultivars is the most effective way to prevent the occurrence of these diseases. Thus, the present study aimed to identify popcorn lines that have the potential for baby corn production and are resistant to the main leaf diseases that affect the crop. The experiment was conducted in randomized blocks with four replications of 30 lines in each area, during two planting seasons. The area was located at the Federal Institute of Espírito Santo (IFES) Campus of Alegre, situated in Rive district, Espírito Santo State, Brazil. Using the obtained data, the area under the disease progress curve was obtained. Subsequently, analysis of the joint variance of the data was conducted, and when a significant effect was found, a grouping of means test was conducted. The Mahalanobis distance for each pair of lines was also calculated, and the genetic distance matrix was used to construct a dendrogram using the UPGMA method. Considering the averages obtained for the three diseases (Southern corn leaf blight, Northern corn leaf blight, and Southern rust), lines L61, L63, L65, L683, L684, L685, L691, L694, and L695 were identified as possible donors of resistance alleles for multiple diseases. Multivariate analysis efficiently grouped the lines L61, L63, L684, L685, and L691, which are described as most resistant in the univariate analysis. [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.)

Conservation agriculture plays an important role in the sustainability of production systems, notably for globally significant crops such as cotton. This study explores the integration of the no-tillage system (NTS) with integrated pest management (IPM) by incorporating cover crops. The aim is to assess the impact of these living or dead covers on the management of insect populations, the indices diversity of phytophagous insects and natural enemies, and to investigate the population fluctuation of these arthropods, considering a variety of crops in the NTS before and after cotton planting. The trial, conducted over two consecutive cropping seasons in Mato Grosso do Sul State, Brazil, employed a randomised block design with four repetitions. The treatments included cover crops with the highest potential for use in the region, such as millet ( Pennisetum glaucum glaucum L.), corn ( Zea mays L.), brachiaria ( Urochloa ruziziensis ), black velvet bean ( Stizolobium aterrimum ), forage sorghum ( Sorghum bicolor L.), and white oats ( Avena sativa L.) and a mix of white oats with brachiaria. The results indicated that the black velvet bean stands out as the most effective cover crop, providing the best performance in terms of non-preference to the attack of the evaluated pest insects. Conversely, brachiaria proves to be more susceptible to infestations of Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), and Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). The study underscores the relevance of the judicious choice of cover crops in IPM and in promoting agricultural biodiversity, creating a strategic tool to enhance the sustainability and efficiency of the cotton production system in the context of the NTS.

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.)

This work aims to characterize the arbuscular mycorrhizal association between maize genotypes and the effects of soil physical–chemical attributes on the symbiosis. A preliminary greenhouse assay evaluated five maize landraces and five conventional modern genotypes in non-sterile, low-P soil. Sixty days after sowing, we measured plant height, stem diameter, shoot and root dry biomass, root colonization structures, and shoot P concentration and total accumulation. In a second stage, a 2-year on-farm study evaluated how soil physical–chemical attributes in fields with three plant genotype groups affected the arbuscular mycorrhizal fungal symbiosis in a maize diversity microcenter in Southern Brazil. We collected soil and plant material in farms growing landrace, conventional modern genotypes, or genetically modified (GM) maize. There were five collection points at each group, and we measured mycorrhizal colonization, soil physicochemical attributes, and shoot phosphorus concentration. The greenhouse study showed that genotypes have different growth strategies for root production and shoot growth. No differences in mycorrhizal colonization rates occurred among landraces and modern maize genotypes in the low-P soil. The field study showed that soil and climate conditions had a more marked effect on mycorrhizal root colonization than plant genotype groups (landrace, conventional modern genotypes, or GM maize). [ABSTRACT FROM AUTHOR]

Emission of nitrous oxide (N2O) can be reduced using enhanced efficiency nitrogen fertilizers (EEFs), such as urease inhibitors and coating technologies. In this study, we evaluated the potential of EEFs to reduce N2O emissions in maize in a clayey Inceptisol subjected to no-till management under summer subtropical conditions, in southern Brazil. The EEF sources used included urea containing N-(n-butyl) thiophosphoric triamide (UR-NBPT), polymer-coated urea (UR-pol), in addition common urea (UR), nitrate (CN) and control treatment without the application of nitrogen fertilizer. N2O emissions were assessed using the static chamber method during one maize season and analyzed through non-linear regression, using a logistic model. The accumulated emission was 0.817, 0.613, 0.457 and 0.393 kg N2O ha−1, for CN, UR, UR-pol and UR-NBPT, respectively. The maximum daily emission of N2O did not vary between amidic forms, however for CN it occurred on the 4th day after application (DAA), while for urea forms it occurred on average at 5.3 DAA. The average N2O emission factor (FE-N2O) was 0.51%, approximately half the standard factor proposed by the Intergovernmental Panel on Climate Change (IPCC), which is 1%. The application of nitrogen increased the maize yield in relation to the control, but the sources of nitrogen did not differ, with an average yield of 10,455 kg ha−1. Based on our findings, the use of UR-NBPT and UR-pol in subtropical agroecosystems provides environmental benefits, by reducing N2O emissions in comparison with conventional nitrogen fertilizers (CN and UR), however, the EEFs did not offer agronomic advantages in maize yield. [ABSTRACT FROM AUTHOR]

Insecticides typically are used to control Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) larvae in corn crops; however, both eggs and larvae are affected by these applications. The purpose of this study was to evaluate the effects of 9 insecticides commonly used on corn crops in Brazil on ovicide and embryonic development of S. frugiperda. The insecticides were applied with an airbrush to the outer surface of eggs at 72, 96, 120, 144, and 168 h after oviposition. Larval emergence rates then were calculated. Eggs in the control and the alpha-cypermethrin and methomyl + novaluron treatment were evaluated by light microscopy to investigate possible histological changes in the embryos. The insecticides methomyl + novaluron, chlorantraniliprole + lambda-cyhalothrin, and deltamethrin reduced the emergence rate of S. frugiperda larvae. A mixture of alphacypermethrin and methomyl + novaluron did not affect the embryonic development of S. frugiperda; however, methomyl + novaluron-treated larvae did not emerge. Therefore, the insecticides methomyl + novaluron, chlorantraniliprole + lambda-cyhalothrin, and deltamethrin have an ovicidal effect and may be recommended for managing S. frugiperda. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the main cereal crops grown around the world and is widely used as food, feed and raw material in various industries. However, the crop is sensitive to weather conditions, and this causes large variations in yield between crop seasons. Suboptimal irrigation can be used to secure reasonable yields with increased water productivity. For maize grown offseason in the Cerrado biome of Brazil, there is little knowledge about the benefits of suboptimal irrigation. This study was designed to evaluate the effect of different irrigation amounts and two Brachiaria cultivars intercropped with maize on maize grain yield, biomass production for silage and water productivity in the second crop season. The study was conducted at Embrapa Milho e Sorgo Experimental Station, Sete Lagoas, MG, Brazil, in 2018 and 2019. Six irrigation levels were obtained by using a line-source sprinkler irrigation system. The irrigation levels used ranged from 94% to 11% of the cumulative reference evapotranspiration (ET0) in 2018, and from 90% to 34% of ET0 in 2019. Suboptimal irrigation above a certain level did not cause a significant decrease in silage biomass (59% and 71% of the ET0, in 2018 and 2019, respectively) and grain productivity (48% and 60% of the ET0, in 2018 and 2019, respectively). Additionally, there was an increase in crop water productivity and irrigation water productivity, for biomass of both silage and grains. The results demonstrate the potential of suboptimal irrigation as a strategy to reduce water resource usage while maintaining acceptable productivity levels. [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.)

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.)

Biscuit bran (BB) is a co-product with worldwide distribution, with Brazil as the second largest cookie producer in the world with 1,157,051 tons. We evaluate the impact of completely replacing corn with BB on the characteristics and morphometry of carcass of purebred and crossbred Morada Nova lambs using machine learning techniques as an auxiliary method. Twenty male lambs from two genetic groups (GG) were used: purebred red-coated Morada Nova (MNR) and crossbred MNR × white-coated Morada Nova (MNF1). Supervised and unsupervised machine learning techniques were used. No interaction (P > 0.05) was observed between diets (D) and genetic groups (GG) and no simple isolated effect was observed for carcass characteristics, qualitative-quantitative typification of the Longissimus dorsi muscle, weight of non-carcass components, weight and yield of commercial cuts and carcass morphometric measurements. The formation of two horizontal clusters was verified: (i) crossed lambs with corn and BB and (ii) purebred lambs fed corn and BB. Vertically, three clusters were formed based on carcass and meat characteristics of native lambs: (i) thermal insulation, body capacity, true yield, and commercial cuts; (ii) choice, performance, physical carcass traits, and palatability; and (iii) yield cuts and non-carcass components. The heatmap also allowed us to observe that pure MN lambs had a greater body capacity when fed BB, while those fed corn showed superiority in commercial cuts, true yields, and non-carcass components. Crossbred lambs, regardless of diet, showed a greater association of physical characteristics of the carcass, performance, palatability, and less noble cuts. Crossbred lambs, regardless of diet, showed a greater association of physical characteristics of the carcass, performance, palatability, and less noble cuts. BB can be considered an alternative energy source in total replacement of corn. Integrating of machine learning techniques is a useful statistical tool for studies with large numbers of variables, especially when it comes to analyzing complex data with multiple effects in the search for data patterns and insights in decision-making on the farm., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Aiming at increasing productivity and maintaining the equilibrium of the corn crop system, the objective of this work was to analyze the phenotypic correlations of cowpea as an alternative of green manure in corn crop. The study was conducted in rural Mineiros, GO, Brazil. The soil was classified as Quartzarenic Neossol. The experimental design was randomized blocks in factorial 6x2, corresponding to 6 corn hybrids [Syn7613, 20A78, DKB310, CD3770, P3250 and P3646] in two fertilization methods [(Green Manure System - GMS: Caupi bean straw - Vigna unguiculata L.) and (Conventional Fertilization System - CFS: formulated 8-25-15)], in 4 repetitions. In the implementation of CFS, 480 kg ha-1 of formula 8-25-15 were used; whereas for the GMS, 231 kg ha-1 of MAP and 124 kg ha-1 of KCl were used to compensate for the P and K elements of the CFS. The cultural management pertinent to pest control were performed using the best practices of integrated pest management. The obtained data were submitted to the assumptions of the statistical model, verifying the normality and homogeneity of the residual variances, as well as the additivity of the model. Uni and multivariate models were used. The analyzes were performed at the interface Rbio and R, besides the Software Genes. It was identified in the analysis of phenotypic correlations that the CD3770 corn hybrid was efficient when used cowpea as an alternative of green manure. [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.)

Maize silage is the main conserved roughage used in animal feed in Brazil and improving its quality has great relevance. The aim of this experiment was to evaluate the characteristics of maize silage, containing different percentages of soybean biomass. In this way, different percentages of soybean green biomass added to maize ensilage (0, 10, 20, 30 and 40% - experiment 1 and 0, 10, 20, 30, 40 and 50% in experiment 2) were evaluated. Experiments were laid out as a completely randomized. Variables were submitted to analysis of variance and when it present significance was applied regression analysis. Silage ashes increased as soybean biomass increased. Regarding to the neutral and acid detergent fiber and the amount of total digestible nutrients, there was no effect of the treatments. At experiment 1, silage crude protein increased from 7.5 to 12.6% from sole maize silage to the silage with 39.2% of soybean dry biomass, which represent an increase of 67.24%. At experiment 2, it increased from 6.77 to 12.09%, which represent 78.58% more protein at the treatment with 50% of soybean green biomass (41% dry matter of soybean) in relation to the sole maize silage. At experiment 2, for every 1% increase in soybean dry matter biomass addition, there was an increase of 0.1% of maize silage crude protein. The addition of soybean biomass to corn silage increases the ashes and crude protein content of silage. [ABSTRACT FROM AUTHOR]

Soybean is the main agricultural crop in the State of Mato Grosso do Sul, Brazil. It is primarily cultivated in a crop succession system, in wich soybean is grown in spring/summer, followed by corn or graminaceous pastures in autumn/winter as a second crop. Due to the intensive cultivation, new phytosanitcuy problems have arisen, among them the root-lesion nematode, Pratylenchus brachyurus, which besides causing damage to plant roots, can be important gateway for other soil pathogens. The recent occurrence of high nematode popidation densities has brought great concern due to the limited resistant soybean genotypes available. Besides, the use of nematicides only reduces nematodes popidations temporarily. A viable alternative for the control ofsoil nematodes could be the use ofCrotalaria spp. in succession or rotation with soybean. Crotalaria is immune or a bad host to the nematode, besides having high capacity of biological nitrogen fixation. Thus, the objective of the present research was to define the best way of insertion of this legume as a second crop in soybean production systems to reduce the population density of the root-lesion nematode. Two experiments were carried out: one in the field, in an infested area, and other in a greenhouse. In both experiments, the treatments were: 1) Zea mays, 2) Brachiaria brizcmtha cv. Xaraés,, 3) Z. mays + Crotalaria spectcibilis, 4) Z. mays + C. ochroleuca, 5) B. brizantha cv. Xaraés + C. spectabilis, 6) B. brizantha cv. Xaraés + C. ochroleuca, 7) C. spectabilis, and 8) C. ochroleuca. The effect of the treatments was evaluated by estimating the number ofnematodes in the roots ofautumn/winter crops, as well as in the roots of the soybean cidtivated in the sequence. The cultivation of both Crotalaria species provided suppression ofthe nematode population. However, when intercropped with corn or Xaraés palisade grass, the suppressive effect of Crotalaria was supplanted by com and Xaraés palisadegrass susceptibility to the root-lesion nematode. [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 Agronomía Colombiana is the property of Universidad Nacional de Colombia 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 Applied Technology for Agricultural Science / Revista Brasileira de Tecnologia Aplicada nas Ciências Agrárias is the property of Brazilian Journal of Applied Technology for Agricultural Science 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 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.)

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., (© 2023. Sociedade Entomológica do Brasil.)

The corn cropping system can influence the natural enemy identity and the number of Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae) individuals infesting the cartridge, ear and stem of this plant. The objectives were to identify the S. frugiperda natural enemies and differences in the number of individuals infesting the cartridge, ear and stem of corn plants under conventional and organic cropping systems, in Brazil after an initial collection of adult males through semiochemical traps. We also evaluated key morphometrical parameters of the larva and factors contributing with the viability of S. frugiperda. A total of 16 and 136 adult males was trapped, and 1,124 and 1,112 larvae was recovered from conventional and organic systems with 4.7 and 6.7% of them parasitized by dipteran and hymenopteran, respectively. Most of the parasitoids recovered had occurrence in both cropping systems, except Cremastinae and Ophion flavidus Brullé, 1846 (Hymenoptera: Ichneumonidae), which were recorded only in organic and Campoletis sp. (Hymenoptera: Ichneumonidae) only in conventional corns. The number of parasitoids recovered was similar in corn plant samples between both cropping systems. A total of 152 and 31 larvae was recovered from corn ears under conventional and organic systems, respectively. Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) was recovered from all samples under conventional system. The larva length was overall similar between cropping systems. Parasitism by dipteran and hymenopteran, infection by microorganisms, larva mortality by undetermined causes, and differences in viability of S. frugiperda stages were factors contributing with the supression of this pest. The new associations and parasitoids reported represent possibilities of expanding the biological control strategies to manage S. frugiperda in corn crops.

The present study aimed to evaluate the influence of increasing levels of corn straw replacement of sorghum silage on average daily gain, loin eye area, subcutaneous fat thickness, weight of commercial cuts, leg tissue composition, and physico-chemical characteristics of the meat from F1 Santa Inês × Dorper lambs maintained in a feedlot system. Treatments consisted of 0, 33, 66 and 100% corn straw replacement of sorghum silage. There were thirty-six 150-day-old male lambs. Corn straw replacement of sorghum silage in lamb feed reduced the average daily gain and weight of the ribs, besides promoting a quadratic influence on leg fat content. However, there was no influence on commercial carcass cuts, leg muscle index, leg tissue composition, and physico-chemical characteristics of the meat. Thus, corn straw can be used as alternative feedstuff for sheep rations to improve the production of high-quality sheep meat in semi-arid regions.