Brazilian Agricultural Research Articles

Features of anaerobic digestion plants in the brazilian agricultural sector

• Most of the anaerobic digestion plants in Brazil are in agriculture and livestock. • Agriculture and livestock produce a small part of the biogas of Brazil. • Most anaerobic digestion plants are small. • The number of biogas plants in agriculture and livestock has grown exponentially. • Most of the units produce electricity. In the context of Brazilian agriculture, anaerobic digestion (AD) is an opportunity, and there are technical and economic conditions to explore. Thus, this study investigated the characteristics of anaerobic digestion plants in Brazilian farming. We carried out a descriptive statistical analysis of anaerobic digestion plants in the agricultural and livestock sector in Brazil. The anaerobic digestion plants in operation have increased exponentially from 2003 to 2020. About 79% of the anaerobic digestion plants in Brazil use agricultural and livestock waste, but combined, they only produce 11% of the total biogas; 31% of these plants produce between 150,000 and 200,000 Nm³/biogas per year, and 78% produce less than 500,000 Nm³/biogas per year. About 89% of all AD plants in the agricultural and livestock sector produce electrical energy. For most Brazilian rural properties, a small AD plant capable of producing electricity is ideal. Our results will facilitate the development of technologies focused on the needs of rural properties, and we believe that this is one of the keys to promoting a circular bioeconomy in agriculture.

Análise espaço-temporal de mosca-branca Bemisia tabaci (Genn., 1889) biótipo B (Hemiptera: Aleyrodidae) na cultura da soja, no município de Paragominas - Pará

The objective of this study is to evaluate the progress of whitefly Bemisia tabaci biotype B infestation during the crops of 2015, 2016 and 2017, to identify between crops studied in which they increased or decreased infestation and in which month the infestation was more representative, to identify among the cultivars which one or which are most susceptible to the attack and to map the areas of incidence of the whitefly. The research to obtain the data was carried out in the municipality of Paragominas and the data were obtained from Defense Agency of the State of Pará according to the methodology based on a model predefined by the agency. Climatic data on rainfall (mm) for crops were obtained through a database of the Brazilian Agricultural Research Corporation meteorological station. For statistical analysis of data, a database was built into Microsoft Excel spreadsheets. Data were analyzed through regression analysis and compared by the Tukey and Scott & Knott test. For the preparation of the whitefly infestation maps, the Spatial Analyst extension in the ArcGIS 10.1 software was used. In the studied area, the month of April is the one with the highest incidence of the pest, the crop of 2017 presented greater infestation, the cultivar P99R03 RR was the most susceptible to the attack of whitefly, and the cultivars P98Y51 RR and FT PGM, were more resistant to whitefly (B. tabaci) biotype B than the other cultivars.

Using leaf-based hyperspectral reflectance for genotype classification within a soybean germplasm collection assessed under different levels of water availability

ABSTRACT Because of the major international issue of intellectual property rights over seed technology, time-efficient methodologies that could characterize and monitor soybean genotypes are increasingly needed as they contribute to royalty collection and better management of seed genetics, leading to more efficient production strategies. This research aims at developing models capable of spectrally classifying soybean genotypes, at leaf scale, under different levels of water availability. Leaf reflectance spectra were collected using the Fieldspec 3 Jr. spectroradiometer, a hyperspectral proximal sensor. Two experiments were conducted at Embrapa Soja (Brazilian Agricultural Research Corporation). Experiment I was carried out in a plant growth chamber, using 12 soybean genotypes with different tolerance levels to drought, submitted to irrigation and water deficit treatments, where 214 spectral samples were collected. Experiment II was conducted in a greenhouse, using 164 soybean genotypes (from 15 different countries) with different responses to drought, submitted to irrigation and water deficit treatments, where 6,046 spectral samples were collected. Principal component analysis (PCA) was used to explore the qualitative spectral differences among the evaluated genotypes within each spectral dataset, and the stepwise procedure was carried out to select the wavelengths that best discriminate the soybean genotypes. Linear discriminant analysis (LDA) was used to obtain a model of classification of each leaf-based reflectance spectrum for each soybean genotype by its spectral behaviour. The acquired leaf reflectance was similar among soybean genotypes. The PCA explained over 96% of the spectral variance in the first three principal components, and the stepwise procedure selected 70 and 410 spectral bands in each dataset. In Experiment I, LDA presented an accuracy of 100%. In Experiment II, the LDA classified 149 genotypes with an accuracy of over 90%. The obtained results demonstrate the great potential of the spectral classification of soybean genotypes at leaf scale, regardless of the water status of the plants.

Inovação em cultivares: panorama das proteções e registros da soja no Brasil

Technological innovations applied to seeds has been supported in Brazil. The establishment of legal mechanisms of intellectual protection and rules to commercialize plants and seeds were responsible for the growth of research and development of new crops. The soybean is the main crop produced in the past years in Brazil and, for this reason, the main goal of this research is to show the scenario of innovation technology of soybean seeds, highlighting the protection and records of crops in Brazil. The scope of our analysis reaches the period between 1998 to 2018.The questionnaire survey of quantitative approach and descriptive strategy was collected based on information from CultivarWeb database (in special from SNPC and RNC) from Ministério da Agricultura Pecuária e Abastecimento – MAPA (Ministry of Agriculture, Livestock and Supply). The secondary data were worked on Excel® Software by using descriptive statistics. The result of this questionnaire survey showed that EMBRAPA (Brazilian Agricultural Research Corporation) is the main public institution active in seed innovations and leader with the most important protection certifications and soybean crop records in Brazil. We also observed strong participation from foreign companies in this market, especially the ones that support the protection and record of transgenic soybean crops. We concluded that the number of records of soybean crop commercialization are higher than the protection certification.

Corporate Foresight: The Strategy of Looking to The Future in a Research Organization

Purpose – The purpose of this paper is to present the practice of foresight at a public research organization in Brazil. Theoretical framework – It was used the concept of foresight to research institutes of a public nature, from the perspective of corporate foresight. Design/methodology/approach – A case study was carried out at the Brazilian Agricultural Research Corporation (EMBRAPA). The type of case study adopted was the single case study, with an emphasis on in-depth understanding of the investigated case. The phenomenon studied was the accumulated experiences and foresight practices within a research organization. Findings – EMBRAPA has a formal structure and processes related to foresight, indicating the importance that the company places in foresight exercises to support decision making. To this end, it has been employing several foresight exercises to assist strategic planning, research agenda definitions and identification of emerging and future technologies. Originality/value – According to the literature, it was possible to understand that public research organizations can also use foresight to establish strategic research priorities to answer national and international trends in S&T (Science and Technology) well as to the development and societal needs.

FeedEfficiencyService: An architecture for the comparison of data from multiple studies related to dairy cattle feed efficiency indices

The increased demand for food worldwide, the reduced land availability for livestock production, the increasing cost of animal feed and the need for mitigating livestock-related greenhouse gas emissions have driven the search for animal feeding systems that proves more efficient. To tackle this problem, we propose the use of computational support to help researchers compare data on feed efficiency, therefore improving economic and environmental gains. As a solution, we present an integrative architecture capable of combining heterogeneous data from multiple experiments related to dairy cattle feed efficiency indices. The proposed architecture, called FeedEfficiencyService, classifies animals according to feed efficiency indices and allows visualizations through ontologies and inference engines. The results obtained from a case study with researchers from the Brazilian Agricultural Research Corporation – Dairy Cattle (EMBRAPA) demonstrate that this architecture is a supporting tool in their daily work routine. The researchers highlighted the importance of the proposed architecture as it allows analyzing animal data, comparing experiments, having reliable data analyses, and standardizing and organizing data from experiments. The novelty of our approach is the use of ontologies and inference engines to enable the discovery of new knowledge and new relationships between data from feed efficiency-related experiments. We store such data, relationships, and analyses of results in an integrated repository. This solution ensures unified access to the processing history and data from diverse experiments, including those conducted at external research centers.

Brazilian varieties of acerola (Malpighia emarginata DC.) produced under tropical semi-arid conditions: Bioactive phenolic compounds, sugars, organic acids, and antioxidant capacity.

Acerola fruit has gained prominence for its high nutraceutical value, associated with high levels of ascorbic acid and phenolic compounds. The objectives of this study were to analyze the chemistry composition and antioxidant capacity in seven Brazilian varieties of acerola. All acerola genotypes were harvested at the red ripe maturity stage, and the fruit were subjected to metabolite analyses by High-Performance Liquid Chromatography. The varieties presented high levels of ascorbic acid and malic acid. The main sugars observed in acerola were glucose and fructose. Cyanidin-3-rhamnoside was the main phenolic compound in the fruit (149-682mg/kg FW), which had higher concentration in the varieties BRS 235-Apodi, BRS 236-Cereja, and BRS 237-Roxinha. Other phenolic compounds also observed in the fruit were quercetin-3-glucoside, isorhamnetin, catechin, procyanidin A2, naringenin, hesperidin, chlorogenic acid, and trans-resveratrol. In conclusion, the observed wide range of acerola nutraceutical properties was related to the high genetic variability among genotypes. PRACTICAL APPLICATIONS: Brazil is the world's largest producer, consumer and exporter of acerola, with commercial orchards distributed all over the country. According to the Brazilian Ministry of Agriculture, Livestock and Supply, about eighteen registered varieties of acerola have been produced in the country. Among them are the varieties developed by Breeding Programs at the Brazilian Agricultural Research Corporation (Embrapa). Despite the great diversity of studies about acerola composition, only a few studies have focused on analyzing specific varieties. Therefore, limited information is currently available on the profile of metabolites of commercial interest in acerola varieties, such as sugars, organic acids and some phenolics. This study showed that acerola nutraceutical properties was highly dependent on the genotype.

Is domestic agricultural production sufficient to meet national food nutrient needs in Brazil?

Reducing the impacts of agriculture on the environment is one of the greatest challenges of this century. In Brazil, it is often argued that more land use change is needed to achieve food security. However, analyses seeking to understand the dynamics between agricultural production for exports and food intended for the Brazilian population have not approached the question if national agriculture is sufficient to provide Brazilians with the necessary nutrients, according to nutritional recommendations. In this sense, we sought to combine supply and dietary requirements for food (calories and nutrients) to assess trends in nutrient production and how future population projections and possible changes in diets would affect land necessity for nutritional security. We use sub-national data on agricultural production, population, Food Balance Sheets from FAO, and a compilation of nutritional information on the Brazilian agricultural production. Our results show that, in the last three decades, Brazil produced enough food calories to feed on average 115% of its population. We found that the agricultural land in 2017, without any expansion, is sufficient to feed, at least, 105% of projected population in 2060, considering the same productivity and dietary patterns. In a vegan diet scenario, less than 10% of the land dedicated to agricultural production in the past 30 years would be required. Despite limitations on supplying certain micro-nutrients, a vegan diet would require even less land in the future. We conclude that Brazilian agriculture could deliver enough food to meet Brazilians' nutritional needs without further land expansion. Food production is compatible with environmental conservation in Brazil, especially if meat consumption is reduced.

Estudos ecogeográficos de Eplingiella fruticosa (Salzm. Ex Benth. Harley& J.F.B. Pastore): Uma espécie medicinal do semiárido do Brasil

A Lamiaceae é uma família de plantas com importantes aptidão medicinal, entre elas, a Eplingiella fruticosa (Salzm. Ex Benth. Harley& J.F.B. Pastore). Como a exploração desse vegetal dá-se de forma extrativista, existe um potencial risco de erosão genética, o que torna essencial estudos que incrementem estratégias de conservação, domesticação e melhoramento. O objetivo foi realizar estudos ecogeográficos com vistas a identificar interações do ambiente que possam ser preditivas do crescimento e desenvolvimento da espécie. Foram levantados dados edáficos, climáticos, relevo, geomorfológicos, fitogeográficos e biomas, nos sítios de ocorrência natural, nas mesorregiões do centro-norte, nordeste, metropolitana de Salvador na Bahia e mesorregiões leste e agreste no estado de Sergipe. As informações foram coletadas em visitas in situ e coletados em sites especializados como IBGE, INPE, INMET e EMBRAPA. Os dados foram submetidos a análise estatística (PCA). Concluiu-se que o ambiente de crescimento da espécie, tipifica-se como de solos arenosos, baixa fertilidade, elevado concentração e teor de alumínio (Al+3), nos domínios do bioma caatinga, mata atlântica e agreste dos estados Ba e SE, em uma larga faixa de adaptação às variantes de temperatura, chuva e altitude.

Genetic diversity via REML-BLUP of ex situ conserved macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] ecotypes

Macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.], a palm tree native to Brazil, has a high potential as an alternative source for vegetal oil production. It has several applications in the cosmetics, pharmaceuticals and food industries, and for the production of biofuels. The conservation and characterization of its germplasm are essential for progress in genetic improvement. In this sense, a study of genetic divergence was carried out based on predicted genetic values of 88 accessions form the Active Germplasm Bank of Macauba of EMBRAPA (Brazilian Agricultural Research Corporation). Seven morpho-agronomic characters were observed. The obtained dendrogram generated seven groups. There was a tendency to group accessions according to geographic origin. The graphical dispersion of accession scores plotted in a two-dimensional space showed a pattern correlated to the clusters observed in the dendrogram. The first two principal components (PC1 and PC2) explained 70.4% of the total divergence. The most important traits associated with PC1 and PC2 were the number of fruit bunches and fruit volume, respectively. The application of mixed models in the study of divergence was useful in structuring the germplasm. The structuring of the germplasm is crucial to assist in the choice of parents aiming the selection of recombinant individuals with a superior performance in segregating generations.

Yield Prediction in Soybean Crop Grown under Different Levels of Water Availability Using Reflectance Spectroscopy and Partial Least Squares Regression

Soybean grain yield has regularly been impaired by drought periods, and the future climatic scenarios for soybean production might drastically impact yields worldwide. In this context, the knowledge of soybean yield is extremely important to subsidize government and corporative decisions over technical issues. This paper aimed to predict grain yield in soybean crop grown under different levels of water availability using reflectance spectroscopy and partial least square regression (PLSR). Field experiments were undertaken at Embrapa Soja (Brazilian Agricultural Research Corporation) in the 2016/2017, 2017/2018 and 2018/2019 cropping seasons. The data collected were analyzed following a split plot model in a randomized complete block design, with four blocks. The following water conditions were distributed in the field plots: irrigated (IRR), non-irrigated (NIRR) and water deficit induced at the vegetative (WDV) and reproductive stages (WDR) using rainout shelters. Soybean genotypes with different responses to water deficit were distributed in the subplots. Soil moisture and weather data were monitored daily. A total of 7216 leaf reflectance (from 400 to 2500 nm, measured by the FieldSpec 3 Jr spectroradiometer) was collected at 24 days in the three cropping seasons. The PLSR (p ≤ 0.05) was performed to predict soybean grain yield by its leaf-based reflectance spectroscopy. The results demonstrated the highest accuracy in soybean grain yield prediction at the R5 phenological stage, corresponding to the period when grains are being formed (R2 ranging from 0.731 to 0.924 and the RMSE from 334 to 403 kg ha−1—7.77 to 11.33%). Analyzing the three cropping seasons into a single PLSR model at R5 stage, R2 equal to 0.775, 0.730 and 0.688 were obtained at the calibration, cross-validation and external validation stages, with RMSE lower than 634 kg ha−1 (13.34%). The PLSR demonstrated higher accuracy in plants submitted to water deficit both at the vegetative and reproductive periods in comparison to plants under natural rainfall or irrigation.

Social Profit of Legal Metrology in the Brazilian Electricity Sector

In Brazil, despite of the undeniable importance of metrology in society, there is still no consensus as to the most effective way to “quantify” this statement. The aims of this study is to present a method to quantify the social impact caused by legal metrological control, focusing on voluntary verification and legal metrology expertise in electrical energy meter . In this sense, this article presents a model, developed exclusively for the public sector, with the objective of quantifying the return or economy in favor of society through National Legal Metrology System direct and indirect actions in the Brazilian electricity sector, considering the 2017 year. This model is an adaptation of Social Profit mode the “Brazilian Agricultural Research Corporation – Embrapa”. . Only laboratories under the control of the Legal Metrology Board, through their delegated bodies, which perform or supervise voluntary checks and metrological examinations performed by the technicians of the Brazilian Network of Legal Metrology and Quality – RBMLQ, were considered. Next step, performance indicators were proposed and validated to obtain social profit. The data show that Inmetro’s actions enable a return to society of US$ 32 million for each US$ 1 million of investment in this activity, pointing to the effectiveness of the model in quantifying the social profit of the agency. In a more detailed analysis it was possible to evaluate a potential revenue recovery for the states, throughTaxes, of the order of US$ 400 million, if the actions of expertise and verification are intensified, pointing to a promising horizon of revenue increase for the Brazilian government through the fight against fraud. Preliminary analyzes show both the massive presence and extreme remoteness of the state are not the best management models to be adopted for the electricity sector. The study suggests, at first, a direct correlation of Inmetro intervention and participation actions in partnership with the private sector in the electricity sector and revenue recovery with reduction in the increase of electric bills. Thus, we infer that the presence of the state as regulator in this case can be effective if adapted to reality. Further studies, however, need to be done. Social profit proved to be effective for use in actions to improve public governance, another point to be explored further on.

Embrapa and the construction of scientific heritage in Brazilian agriculture: Sowing memory

AbstractMotivationThe Brazilian Agricultural Research Corporation, Embrapa, is well known for incorporating the Cerrado into Brazil’s modern agriculture through its discoveries of how to improve infertile soils and to develop soybean seeds adapted to the tropics. Known as the Tropical Revolution, Brazil’s own Green Revolution, this past episode continues to define Embrapa’s identity and Brazil’s agricultural science and technology, reinforcing a view of agricultural development while neglecting alternatives.PurposeThis article seeks to understand how Embrapa has carved its name in Brazil’s agricultural history, creating a powerful national brand with global recognition. It explores what constitutes Embrapa’s “organizational heritage,” how this has been built within the organization and to what effect.Approach and methodsTo commemorate Embrapa’s 40th anniversary in 2014, an official history (“Memória Embrapa”) was written, focusing on the success of the organization and the reasons for this. This source has been reviewed, then combined with evidence from interviews with 29 Embrapa researchers about the strengths and shortcomings of organizational heritage.FindingsEmbrapa’s story of success focuses on selected technological breakthroughs, highly trained and motivated scientists, and a sense of mission towards Brazilian society. This omits, however, some successes, challenges and alternative approaches to research that do not fit well with the simplified history. Three such omissions stand out: (1) the official history barely mentions the concerns about the environmental and social impacts of the spread of large‐scale farming—which much of Embrapa’s research had served; (2) Embrapa created a national seed bank, to which indigenous groups demanded access since they had conserved much of the genetic material in the bank (policy was changed to allow indigenous groups access and to promote a dialogue between the scientists and the farmers); and (3), in similar vein, some scientists in Embrapa endeavour to engage with local expertise, with ethnoscience, to enrich and broaden the research.Policy implicationsRooting Embrapa’s brand in history makes the narrative persistent and hard to challenge. This risks creating a simplified, monolithic narrative about Embrapa and Brazilian agriculture that feeds technocratic fixations with high science and transfer of technology as the dominant pathway to agricultural development and food security. This may have been considered necessary in the 1970s, but increasingly the agricultural research agenda must include environmental sustainability and conservation of agricultural biodiversity, climate change, social fairness and a respectful engagement with different ways of researching, including learning from the longstanding practices of farmers.

National-scale spatial variations of soil magnetic susceptibility in Brazil

Brazil presents high soil variability, however, the soil magnetic susceptibility (χ) distribution on national scale is yet to be investigated. Thus, soil data (218 samples from the literature and 36 original samples) were utilized to estimate soil low frequency χ (χlf) across Brazil through machine learning algorithms (Generalized Additive Model Using Splines, Generalized Linear Model, Random Forest and Support Vector Machine) in order to assess the applicability of such methodology on a nationwide scale. Two variable groups were tested: texture and Fe2O3 contents – Group 1; and texture, Fe2O3, Al2O3, SiO2 contents – Group 2. The best performing model was applied to a database containing 3817 and 3973 georeferenced soil samples from superficial and subsuperficial horizons, respectively, obtained from soil surveys conducted by the Brazilian Agricultural Research Corporation. Polynomial Support Vector Machine using Group 2 variables presented the best performance (R2 = 0.91). Variable importance measurements showed that χlf is chiefly related to Fe2O3 and clay content. The spatial distribution of χlf on national scale varied from very high (>150 × 10−6 m3 kg−1) to very low (≤5 × 10−6 m3 kg−1), considering the interpretation bands that we propose for Brazilian soils. Extensive areas of magnetic soils were associated with their formation upon mafic rocks or iron-rich formations. Despite few exceptions, the observed tendency shows that χlf increases parallel to soil red color, drainage and weathering degree, and hence Rhodic Nitisol, Umbric Nitisol, Rhodic Ferralsol and Umbric Ferralsol presented the highest χlf values.

Identification and quantification of potassium (K+) deficiency in maize plants using an unmanned aerial vehicle and visible / near-infrared semi-professional digital camera

ABSTRACT Brazil is one of the largest producers of maize worldwide. However, this production is threatened due to low soil fertility, especially low levels of potassium (K+). K+ is one of the most important nutrients in plant metabolism, acting on enzymatic activation and also on photosynthetic processes. The identification of its deficiency by using traditional methods is difficult with regard to timely restoration of the nutrient to adequate levels. Therefore, the use of low-cost modified cameras attached to Unmanned Aerial Vehicles (UAVs) are important tools for agricultural monitoring. Nevertheless, there are no reports of studies with the purpose of evaluating the monitoring of K+ deficiency in maize crops using multispectral images captured from UAVs. Therefore, this study aimed at exploring the possibility of identifying K+ deficiency and quantifying the nutrient leaf content by using a Vegetation Index (VI). The experiment was carried out at the National Soybean Research Centre (Embrapa Soja, a branch of the Brazilian Agricultural Research Corporation). The experimental plots were constantly managed in order to obtain different conditions of K+ availability to plants, achieving levels that ranged from severe deficiency to an adequate nutrient level. The following treatments were established: severe potassium deficiency (SPD), moderate potassium deficiency (MPD) and adequate supply of potassium (ASP). The evaluations were performed in the Brazilian maize crop referred to as ‘safrinha, at the V7, V12 and R3 developmental stages, with image capture covering the visible and near-infrared region, using two Fujifilm IS PRO digital cameras attached to an UAV. In these development stages, leaves were collected to determine tissue K+ concentration. The images were radiometrically corrected with the support of calibration targets and reference values, using an Fieldspec 3 Jr. spectroradiometer. The VIs comprised the ratio among the red, green and infrared spectral bands, that is, green normalized difference vegetation index (GNDVI), normalized difference vegetation index (NDVI), ratio between infrared and green (GRVI), ratio between green and infrared (GNIR), ratio between red and infrared (RNIR) and ratio between infrared and red (RVI). Regarding all the treatments assessed, the results showed that foliar K+ was statistically different. The VIs were efficient only in differentiating SPD and ASP treatments at all development stages evaluated. However, none were statistically significant for MPD. The linear regressions showed a high coefficient of determination (R 2) and low root mean square error (RMSE) value; the best prediction of K+ concentration obtained was at V12 for regressions with these VIs: GRVI (R 2 = 0.79, RMSE 4.50 g kg−1) and RVI (R 2 = 0.71, RMSE 4.39 g kg−1). The grain yield values showed that SPD caused an average reduction of 5,645.90 kg ha−1 in relation to the ASP. Considering MPD, the grain yield was 1,242.00 kg ha−1 lower in comparison with ASP. In conclusion, estimating foliar K+ content and identifying its deficiency in maize crops based on the VIs of multispectral images from cameras attached to UAVs is possible, which ensures agility to these evaluations in a non-destructive manner, improving efficiency of K+ fertilization and providing farmers with a new tool.

Green Growth and Agriculture in Brazil

This paper addresses Green Growth and Agriculture in Brazil, analysing the National Plan for Low Carbon Emission in Agriculture (ABC Plan). The main focus is to detail the structure and actions proposed and implemented by the ABC Plan, and also to identify its economic, environmental and social effects. Using a qualitative research approach, desk research was conducted through reports, newspaper articles, and official documents from the Brazilian government and the Brazilian Agricultural Research Corporation (EMBRAPA). The outcomes indicated that the ABC Plan did not address the main components of the literature on green growth policies, such as proper training of human resources in sustainable agricultural techniques, and access to financial support for promoting the implementation of sustainable agriculture systems. The lack of participation of local institutions in the creation and implementation of the ABC Plan is also pointed out.

OCCURRENCE OF NOXIOUS WEEDS UNDER DIFFERENT SOIL MANAGEMENT SYSTEMS

The aim of this work was to identify weed species in areas under different soil management systems. The research was carried out in the Brazilian Agricultural Research Corporation experimental area, in the 2017/2018 harvest, in the city of Boa Vista, Roraima State, Brazil. The experimental design was randomized blocks and the treatments included of five soil management systems (native vegetation, minimum tillage, no-tillage, conventional tillage and conventional tillage with crop rotation). Weed collection, identification, counting and drying were performed and then the phytosociological indices (Relative density, relative frequency, relative abundance, importance value index, relative importance value index and dry mass) were calculated. Variance analysis with means compared by Tukey test (P <0.05), group analysis by hierarchical and non-hierarchical method, and principal component analysis were performed. Correlation coefficients of the variables were estimated. No and minimum tillage systems had the lowest weed rates per square meter. The botanical families Poaceae, Fabaceae and Rubiaceae are the most representative in the studied systems. Concerning relative frequency, the species Cyperus flavus stood out in all treatments other than native vegetation.

Identifying critical factors for agility in innovation ecosystems: an exploratory study in the agriculture sector

Organizational agility is the ability of organizations to adapt and respond to changes, it has been cited to explain the internal dynamics and competition in innovation ecosystems. Would it be possible to identify differences in agility as a measure in such environments? The present article investigates the subject, beginning with a systematic literature review that identified critical factors for agility in innovation ecosystems. Next, an exploratory field study was carried out to identify whether such factors could be observed empirically. An innovation ecosystem in the agriculture sector was chosen - the Brazilian Agricultural Research Corporation - Embrapa. The study allowed identifying agility factors in three sublevels of analysis, the last two being observed at Embrapa: Programs and Portfolios, Organizations and Ecosystems. Finally, future research that focuses on better understanding the phenomenon in innovation ecosystems is recommended.

Estudo comparativo da produção da cana-de-açúcar na microrregião de Vitória de Santo Antão/PE, Brasil

A Zona da Mata Pernambucana se destaca por oferecer solos ricos para a plantação da cana-de-açúcar, devido sua grande importância social, econômica e ambiental para o país. A alta representatividade da cana-de-açúcar no valor da produção comparada aos demais produtos das lavouras temporárias, corroboram para a importância econômica na microrregião. Dispondo de dados provenientes do site da Empresa Brasileira de Pesquisa Agropecuária (Embrapa), a presente pesquisa teve como objetivo, analisar se houve diferença significativa quanto à produção de cana-de-açúcar, em toneladas/ha, entre os períodos de 1990-2003 e 2004-2017, na microrregião de Vitória de Santo Antão/PE, Brasil. Para a análise, foi necessário que se avaliasse, de forma independente, os dois períodos. Assim, utilizou-se o software estatístico IBM SPSS STATISTICS 23, a fim de avaliar a normalidade dos dados através do teste de Shapiro-Wilk, o qual indicou que os dados não seguem normalidade ao nível de significância de 0,05. Em conseguinte, foi aplicado o teste de Mann-Whitney, por ser um teste não paramétrico e considerar a independência dos anos. Os resultados obtidos pelo teste, com significância exata de 0,94 indicaram que não há uma diferença significativa entre os períodos, ou seja, a microrregião mantém uma produção média de 326,54 toneladas de cana-de-açúcar a cada período, o que torna viável a permanência do cultivo de cana-de-açúcar para a mesma.

Cold Tolerance in Sugarcane Progenies Under Natural Stress

Cold stress reduces crop yields and quality, limiting agricultural expansion. The objective of this study was to evaluate cold tolerance in sugarcane (Saccharum spp.) progenies based on physiological and biometric characteristics under natural cold stress. The experiment was carried out at a station of the Temperate Climate Research Center, of the Brazilian Agricultural Research Corporation (Embrapa), in Pelotas, Rio Grande do Sul, where 21 full-sib sugarcane progenies were evaluated in an incomplete block design with six replications. Physiological and biometric characteristics were measured after frost events to determine cold tolerance. The components of variance, genetic parameters and correlations were estimated using mixed models (REML/BLUP). The meteorological data recorded on-site showed the occurrence of 13 frost events (0 °C) and a minimum temperature of − 2.9 °C. Genetic variability for cold tolerance was detected between and within progenies. Narrow-sense heritability was moderate for chlorophyll content (0.23), leaf damage (0.26), stalk damage (0.19) and total soluble solids content (0.44), while heritability at the progeny level was high for all traits (> 0.57). The genotypic values for cold tolerance and yield potential were highest in the progenies RB996962 × RB016916, RB016916 × RB996962, RB867515 × RB92579 and RB106802 × RB036088.