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, Milton Garcia Costa, Eric Victor De Oliveira Ferreira, Nilda Leonor Pezo Peréz, Henrique Da Silva Barata, , Heráclito Eugenio Oliveira da Conceição, Sérgio Dias Do Espírito Santo
Published: 30 May 2021
Journal of Agricultural Studies, Volume 9, pp 1-13; doi:10.5296/jas.v9i3.18577

Abstract:
The use of cover crops has become a common practice in oil palm plantations, ensuring greater sustainability to agroecosystems, increasing nutrient cycling and providing greater savings in the use of mineral fertilizers. In this sense, the objective of this study was to evaluate the accumulation of macronutrients (N, P, K, Ca, Mg and S) in tropical kudzu plants (Pueraria phaseoloides L.) in oil palm plantations. The experiment was carried out in the municipality of Tailândia, Pará State, using a completely randomized experimental design, four replications and seven treatments (ages of oil palm). The accumulation of macronutrients was obtained through the product of nutrient concentrations and the dry matter of the aerial part of the living, dead and total cover of tropical kudzu. The order of total accumulation of cycled nutrients by legumes was Ca, N, K, Mg, P and S. Tropical kudzu cultivation, as a cover plant, contributes to nutrient cycling in oil palm plantations, but this benefit decreased with the age of palm oil trees.
Lucas De Oliveira Soares Rebouças, Julianna Paula Do Vale Figueiredo, Maria Carla Da Silva Campelo, Jovilma Maria Soares De Medeiros, Renata Bezerra Gomes Rebouças, Clodomiro Alves-Junior, Jean Berg Alves Da Silva, Patrícia De Oliveira Lima
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 521-536; doi:10.5296/jas.v9i2.18341

Abstract:
This study aimed evaluating the effects of cold plasma on the quality attributes of Pacific white shrimp (Litopenaeus vannamei). Shrimp were divided into 4 sample groups: one control and the remaining groups subjected to cold plasma at frequencies of 5, 10, and 15 kHz, respectively, during 10 minutes of application followed by evaluation of chemical, physical, microbiological, and sensorial characteristics. Cold plasma contributed significantly to the maintenance of shrimp quality during storage, delaying the melanization process, microbial growth, improving the physicochemical and sensorial qualities of the samples. Exposure of white shrimp to non-thermal plasma at 15 kHz promoted better physicochemical, microbiological, and sensorial results, and increased the shelf life of samples by 5 days, suggesting that the treatment is effective to preserve the quality of shrimp.
Caris Dos Santos Viana, Marcelo De Almeida Guimarães, Hozano De Souza Lemos Neto, Ítalo Marlone Gomes Sampaio, Ana Régia Alves De Araújo Hendges, Janiquelle Da Silva Rabelo
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 505-520; doi:10.5296/jas.v9i2.18344

Abstract:
The aim of this study was to evaluate the competitive ability and physiological aspects of arugula intercropped with different aromatic condiment species. The study was carried out at the Teaching Garden of the Federal University of Ceará, Brazil. A randomised complete block design was used, with four replications and seven treatments: T1 (single arugula), T2 (arugula intercropped with coriander), T3 (arugula and parsley), T4 (arugula and garlic chives), T5 (single coriander), T6 (parsley) and T7 (garlic chives). A physiological evaluation was made of the arugula only. Competitive ability was obtained by calculating the aggressivity index, simplified aggressivity, competitive ratio and compensation ratio. The leaf area index and specific leaf area were calculated. No difference was seen between the treatments with arugula for the physiological factors net photosynthesis, stomatal conductance, rate of transpiration and instant carboxylation efficiency under evaluation within each crop cycle, but there was a difference between the two cycles. The coriander showed the highest aggressivity index and competitive ratio, and was considered more competitive than the arugula, with a higher compensation ratio. As an intercrop, the arugula showed greater competitive ability than the parsley and garlic chives. The greatest leaf area and leaf area index in the arugula plants were seen when intercropped with coriander.
Helton Devison De Lima Silva, Antônio Veimar da Silva, João Henrique Barbosa da Silva, Edson De Souza Silva, José Fidelis Dos Santos Neto, Misael Mendes Soares, Carla Michelle da Silva, Fabio Mielezrski
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 445-461; doi:10.5296/jas.v9i2.18529

Abstract:
Maize (Zea mays) is a cereal widely used in human and animal feeding worldwide, with great socioeconomic importance. This study aimed to evaluate the growth, productivity, and absorption of macro and micronutrients of maize under the application of biostimulant, sulfur, and zinc in a Gleisolo Háplico soil in a microclimate region of the semiarid state of Paraíba, Brazil. The experiment was carried out in a complete randomized block design, a 2x2x2 factorial scheme with eight treatments, and four replications was used. The first factor corresponded to treatment with biostimulant (Presence and absence); the second to sulfur (Presence and absence); and the latter to zinc (Presence and absence). Growth, yield, and macro and micronutrient absorption data were evaluated. Data were submitted to analysis of variance and the means compared by the Tukey test at 5% probability. The number of rows per ear and ear diameter responded positively when the biostimulant was used. Maize under foliar fertilization with zinc nitrate did not show yield increase. The application of sulfur promoted an increase in almost all variables, including yield. The combined application of the three products influenced only the number of rows per ear. The application of sulfur separated or together with biostimulant provided an increase in the absorption of some nutrients by the leaf such as copper, N and K. As a result of fertilization with sulfur, which provided an increase in leaf absorption, mainly of N, also promoted a significant increase in all student variables, including grain productivity.
Wanêssa Tavares Campos Corsini, Fábio Dos Santos Corsini, Marina Ariente Angelocci, Luciana De Paula Naves, Leandro Carlos Paiva, Adriano Bortolotti da Silva, Bruno Cesar Goes, Fernando Ferrari Putti
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 272-282; doi:10.5296/jas.v9i2.18328

Abstract:
World market is increasingly expanding in food production. Coffee has been underscored within the new scenario and positively impacts the economy of the country, together with other crop types. Current analysis assesses the insertion index of new technological resources and the fastness of the production process of coffee culture on small coffee plantations in the south of the state of Minas Gerais, Brazil. Field study comprised the analysis of 225 farms by an open and closed questionnaire. Data, analyzed by cluster analysis, revealed that small farms have invested in technologies and data access technology for harvest and production processing. Corroborating other scientific investigations, the above activity decreased the labor force and consequently triggered an increase in profits for small producers.
Daniel Pereira da Costa, Claudiana De Lima Castilho, Uclédia Roberta Alberto dos Santos, Tainára Cunha Gemaque, Leandro Fernandes Damasceno, Jô De Farias Lima, Kleber Campos Miranda Filho
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 57-72; doi:10.5296/jas.v9i2.18159

Abstract:
The color is an important factor to distinguish the commercialized Amazon river prawns. The accumulation of pigments in the body can vary according to the prawn’s diet. In this work, ethanolic extracts of “buriti” and annatto rich in pigments were obtained and tested comparatively with synthetic astaxanthin in the feeding of adults of Macrobrachium amazonicum, together with a control group without pigments and a newly captured wild group. Levels of body pigments were measured using UV reflective spectroscopy and external staining by colorimetry. Differences were observed in the accumulation of astaxanthin in body tissues, differences in saturation between genders and that annatto extract has greater stability in the feed after water immersion (P˂0.05). Further studies are recommended to verify the ideal dosage of natural pigments in relation to synthetic astaxanthin that benefits the productive development of prawns.
Daniel Pereira da Costa, Claudiana De Lima Castilho, Uclédia Roberta Alberto dos Santos, Tainára Cunha Gemaque, Leandro Fernandes Damasceno, Jô De Farias Lima, Kleber Campos Miranda Filho
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 32-56; doi:10.5296/jas.v9i2.18156

Abstract:
The inclusion of natural extracts and solution of synthetic astaxanthin in the Macrobrachium amazonicum diet were tested to verify their effect on performance, body indexes and total accumulation of astaxanthin in the reproductive tissues and gametes of this crustacean in comparison with newly captured wild animals. The experiment was randomized in blocks (five treatments with three replicates). Four groups were submitted, during 20 days, to diets in recirculation tanks: control diet (CONT); diet containing natural extract of “buriti” (CAR); diet with inclusion of natural “urucum” extract (BIXN), diet with synthetic astaxanthin (ASTX) and NATURAL group (not fed with ration). 180 prawns were used, with 60 males (6.08±1.96 g) and 120 females (4.55±1.03 g) distributed in five groups containing four males and eight females each. There were no significant differences in performance and body indexes. The number of released spermatozoids, live spermatozoids, body and egg pigmentation was higher in BIXN and ASTX treatments. The ASTX treatment was superior to the NATURAL group in the body pigmentation of females and eggs and release of spermatophores by males. These results demonstrate that the use of natural and artificial carotenoid pigments in the diet are beneficial for reproduction of M. amazonicum.
Gustavo Henrique Dalposso, Miguel Angel Uribe-Opazo, Fernanda De Bastiani
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 283-303; doi:10.5296/jas.v9i2.18494

Abstract:
To have information about the soybean productivity over the crop years is essential to define strategies to increase profits and reduce costs and most important to reduce environmental impacts. One form of monitoring is the use of Geostatistical methods, which allow us to obtain maps with more accurate predictions. In this paper, an area of 127.16 ha was studied during six crop years between 2012/2013 and 2017/2018. We found that productivity values vary between crop years, mainly due to uncontrollable climatic factors. The removal of influential points caused changes in the predicted values showed in the maps, and the use of scaled semivariograms allowed us to obtain similar maps to those obtained considering the model without influential points, then there was no need to exclude observations. The use of a model with replicates helped to identify regions where productivity was lower. The use of explanatory variables allowed us to elaborate a more accurate thematic map in the 2017/2018 crop year, which was well evidenced by the prediction standard error map.
Huan Pablo De Souza, , Mauro Valdir Schumacher, Aline Aparecida Ludvichak, Angélica Costa Malheiros, Claudiney Couto Guimarães, José Mateus Wisniewski Gonsalves
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 323-334; doi:10.5296/jas.v9i2.18385

Abstract:
The fine root component, although it represents the lowest proportional biomass in a tree, has an important function in obtaining water and nutrients. In addition, it is an indicator of the physiological quality and growth of a tree. Thus, the objective of the study was to evaluate the spatial distribution of biomass and the density of fine roots in five different fertilizer treatments. The five treatments received increasing amounts of fertilizers. The collections were made between trees in the planting line and between the planting lines. Soil layers of 25 cm x 25 cm x 20 cm (length x width x depth) were collected until reaching a depth of 1 meter. Treatments that had less nutrient input via fertilization showed higher production of fine roots. In general, the line position in the superficial layers showed a higher density of fine roots. There was significant difference between the positions of the land monoliths and between the different layers. Strategically, the lower supply of nutrients via fertilization provided greater investment in the production of fine roots by trees in order to increase the area of absorption and exploration of the soil.
Marco Aurélio Borba Moreira, Amilton Diniz Souza, Fernanda Barbosa Borges Jardim, Luís Carlos Scalon Cunha, Mário Machado Martins, Luiz Ricardo Goulart, Sérgio Antônio Lemos de Morais, Francisco José Torres de Aquino, Welington De Oliveira Cruz, Lucas Gustavo da Costa, et al.
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 73-95; doi:10.5296/jas.v9i2.18139

Abstract:
Soy production in Brazil is an important factor for the agro-industrial, economic, and social development of the country. The expansion of soy in the Brazilian territory is mainly due to the incorporation of new genetic characteristics into cultivars that granted resistance to the Cerrado conditions and to herbicides. Currently, Brazilian soy production is the result of genetically modified cultivars. Studies regarding the chemical composition of soybeans show that qualitative and quantitative variations can occur, depending on the region of production. This work aimed to investigate the chemical composition of soybeans produced in different cities of the Triângulo Mineiro region/MG, Brazil (Harvest 2017/2018) and stored in three warehouses located in the city of Uberaba/MG. The grain analysis was made by liquid chromatography coupled to electrospray ionization mass spectrometry (LC-MS-ESI). The classes of metabolites identified from methanolic extraction were organic acids, phenolic compounds, flavonoids, sugars, amino acids, dipeptides, nitrogenous bases, nucleosides, sphingolipids, and fatty acids. The isoflavones genistein, daidzein, glycitein, genistin, acetyldaidzin, and acetylgenistin were identified in soybeans from the three warehouses. The flavonoid eriodictyol-O-hexoside was also found. The Principal Component Analysis (PCA) from the mass spectrum data obtained by direct injection in the negative and positive modes evidenced the well-defined separation of three groups, indicating that there was variance among the soy samples from each warehouse. The samples from warehouses 1 and 3 showed greater similarity in the Hierarchical Cluster Analysis (HCA) in negative mode, while in positive mode, the samples from warehouses 2 and 3 presented greater similarity.
Matheus Takemi Muchon Nakatani, Mario Henrique Conde, Mariana Green de Freitas, Flávia Carolina Fávero, Lucas Chaves de Paula, Marcos Da Silva Cabrera, Marina De Nadai Bonin Gomes, Ricardo Carneiro Brumatti, Daniel De Castro Rodrigues, Fernando De Almeida Borges
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 188-204; doi:10.5296/jas.v9i2.18032

Abstract:
The economic viability of a commercial oral anthelmintic suspension containing 10% fenbendazole was evaluated in Angus x Nelore cattle in a feedlot. Two groups of 37 animals (treated and non-treated) were formed. A random-block design was used based on initial weight, egg count per gram of feces (EPG) and carcass grade. EPG counts and the determination of weight were performed on Days 0, 42 and 122. Carcass grade and yield were determined on the day of slaughter. Economic viability was evaluated using cost-effectiveness, sensitivity and financial analyses, considering three economic scenarios: most likely (M), optimistic (O) and pessimistic (P). The anthelmintic achieved 99.89% efficacy regarding EPG reduction. The animals exhibited an increase of 20.7 kg in live weight, 20.2 kg in live weight gain and 0.166 kg in daily weight gain (p < 0.05). No effects were found on yield or carcass grade (p > 0.05). The genus Haemonchus predominated at the onset of the study, whereas only the genus Cooperia was found after treatment. A net return of 14.60 USD per animal was found in the treated group, which remained viable under O, M and P scenarios, with respective differences of 18.92%, 12.86% and 91.15% in gross profit. The treatment was financially superior under all scenarios (real, M, O and P), with reductions of 1.89, 1.04, 0.48 and 16.39 years for the recovery of the initial investment. These results demonstrate the importance of economic analysis methods in the evaluation and selection of anthelmintics.
Angel Ramon Sanchez Delgado, Sergio Drumond Ventura
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 151-170; doi:10.5296/jas.v9i2.18389

Abstract:
We present a computational procedure to maximize the production of a given agricultural crop with limited inputs (water-nitrogen), and where a fixed cost (or expense) of the inputs (general problem of agricultural production) is imposed. Theoretically the procedure is based on the Karush-Kuhn-Tucker optimality conditions and numerically was tested with three different scenarios defined in the literature, for the cultures: Lettuce, Oats, Onions and Melons. In each agricultural scenario considered, it was possible to verify that the procedure is a reliable alternative in making agribusiness economic decisions.
Glauber Monçon Fipke, Vinicius Dos Santos Cunha, Evandro Ademir Deak, Jessica Deolinda Leivas Stecca, João Leonardo Fernandes Pires, Guilherme De Almeida Arismendi, Eduarda Grün,
Published: 25 January 2021
Journal of Agricultural Studies, Volume 9, pp 171-187; doi:10.5296/jas.v9i2.18046

Abstract:
The present work aims to evaluate the possibility of anticipating the wheat harvest by the application of non-selective herbicides in the pre-harvest conditions, thereby providing productive and economic viability. In total, 13 treatments were executed, which includes the spraying of different herbicide combinations (glufosinate-ammonium, glyphosate, and paraquat) in the phenological stages (Z-83, Z-85, Z-87, Z-92), and treatments without application of herbicides. Further, the treatment step was followed by providing different harvest conditions such as (i) glufosinate-ammonium: 9.5 and 8.8 days, (ii) glyphosate: 11.2 and 10.9 days, and (iii) paraquat: 7.9 and 8.5, where the first numerical value corresponds to number of days for the year 2016 followed by 2017. A mean reduction in seed yield of 4.6 % (BRS Parrudo) and 25.4 % (TBIO Sinuelo) was observed upon application of herbicides in the first two phenological stages. Additionally, an economic loss reaching up to R$2512 ha-1, was demonstrated. Therefore, the application of the non-selective herbicides glufosinate-ammonium and paraquat in the pre-harvest results in wheat phytointoxication, however, promoting harvest anticipation in 4.8 and 5.3 days, respectively. Jefferson Ferreira da Silva, Stephany Diolino Cunha, Henyo Alves Rodrigues Dias, Matheus Da Silva Araújo, Ednaldo Cândido Rocha, Márcio Da Silva Araújo, Adilson Pelá Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 488-504; doi:10.5296/jas.v9i2.18581 Abstract: The objectives of this study were: to evaluate the leaching potential of B in a Latossolo Vermelho-Amarelo (Oxisol) as a function of sources and doses of this micronutrient; among the sources tested (boric acid, ulexite and the commercial source H2 Boro), to determine the one with the lowest leaching potential; to evaluate leaching losses at different doses in each soil layer evaluated; and to identify chemical and physical variables of soils that influence B leaching. For that, two experiments were conducted in a greenhouse. The first one tested B leaching in the soil, with the three sources under study and five doses of B (0; 12; 24; 36; and 48 kg ha-1), whereas the second experiment evaluated the influence of soil physical and chemical attributes on B leaching using soils randomly collected in 22 localities in southeastern Goiás, Brazil. Regardless of the dose applied, ulexite led to the lowest soluble B content in the profile of the analyzed soils and also in the leachate. Boric acid was the only source that showed a different behavior in relation to B content in the different soil layers and in the leachate. In the soil layer from 21 to 30 cm, ulexite is the source with the lowest soluble B content. The behaviors of the more soluble sources, in this case boric acid and H2 Boro (H2 Agrosciences - Monoethanolamine borate), regardless of the dose, are very similar, being highly leachable in the profile of the Oxisol used. Soils with clayey texture and higher values of H+Al and CEC were able to retain higher B contents in the upper portion their profiles (layers from 0 to 10 cm and 11 to 20 cm), but soils with sandy texture and higher values of sum of bases showed greater B losses by leaching. Washington Duarte Silva da Silva, Jordan Luis Campos Modesto Pereira, Milton Garcia Costa, Adriane Dos Santos Santos, Magda Do Nascimento Farias, Ana Paula Souza Ferreira, Luiz Carlos Pantoja Chuva de Abreu, Lucila Ferreira da Silva, Maria Thalia Lacerda Siqueira Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 462-470; doi:10.5296/jas.v9i2.18446 Abstract: Green spaces are urban spaces that bring man and nature closer together, positively influencing the quality of life of the population. The planning of green spaces is essential in urban areas and Geographic Information Systems (GIS’s) are tools capable of assisting in the identification, management and monitoring of these spaces. The objective of the work was to map the urban vegetation and carry out a survey of potential areas for parks and green areas in the commercial center from the municipality of Capitão Poço - PA. The study was carried out in the commercial center from Capitão Poço, PA - Brazil by obtaining images from the Google Earth software and photointerpreted with the aid of the QGIS software. Finally, the current and potential tree green areas were identified in the georeferenced images. The survey of green areas in the commercial center identified that only 4.74% of the total area contains tree vegetation, in addition to 53% of this vegetation being found around the mother church and the municipal square of Alvorada. For potential green areas, it was found that the commercial center has 5,873.5% more potential areas in relation to current tree vegetation. In this sense, it is observed that the commercial center from the municipality of Capitão Poço contains a low proportion of areas with arboreal vegetation and a high potential for the implantation of parks, forests and other types of green areas. Layara Alexandre Bessa, Mateus Neri Oliveira Reis, , Fabiano Guimarães Silva Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 1-31; doi:10.5296/jas.v9i2.18089 Abstract: The lack of sufficient knowledge on nutritional requirements, as well as efficiency parameters, in the use, absorption, and translocation of nutrients by seedlings in developmental stages may lead to the excessive use of chemical fertilizers, which end up contaminating the environment. Therefore, this research adopted the hydroponic system to elucidate the nutritional requirements of Hymenaea courbaril L. seedlings, a fruit tree of neotropical importance, throughout its development (30, 60, 90, 120, 150, and 180 days after transplantation). Consequently, biometric data on growth and mineral nutrition were obtained and utilized to determine efficiency parameters in the use, absorption, and translocation of nutrients. Although H. courbaril leaves functioned as efficient drains throughout the development, S and Fe accumulated in the roots, owing to their not very mobile nature. The macro and micronutrients that were accumulated the most in the tissues were N and Mn, which even suggested a tendency for H. courbaril to tolerate Mn concentrations that are naturally toxic. The most efficient adoption was observed for the S and Cu nutrients, whereas the most efficiently absorbed nutrients were N (the macro and micronutrient with the greatest accumulation) and Fe (the second micronutrient with the greatest accumulation). However, the seedlings efficiently translocated Ca-N and Mn, i.e., the most accumulated nutrients. Positive effects on growth were correlated with increases in P, Ca, and Mg levels, thus signaling the importance of an optimal supply of these nutrients in obtaining healthy seedlings of this species. This work suggests that to obtain seedlings of H. courbaril in practice, the availability of N, Mn, P, Ca and Mg should be reviewed. Natália Cássia De Faria Ferreira, Ednaldo Cândido Rocha, Fabrício Rodrigues, Solange Xavier dos Santos, Thiago Alves Santos de Oliveira, Elizabeth Amélia Alves Duarte, Daniel Diego Costa Carvalho Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 335-346; doi:10.5296/jas.v9i2.18410 Abstract: The low volume of information related to the interaction of Trichoderma fungi with seeds and seedlings represents a limitation to forest production, and it is important to carry out studies focusing on its effect on plant germinability and formation. The aim was to evaluate commercial products based on Trichoderma spp. in promoting growth of Jacaranda mimosifolia. For initial seedling growth assay, seeds were treated with Trichoderma spp. suspension and placed on germinating paper sheets. At 28 days after sowing (DAS) the following evaluations were: percentage germination (PG), root length (RL), shoot length (SL), total length (TL), fresh root mass (FRM), fresh shoot mass (FSM), fresh total mass (FTM), root dry mass (RDM), shoot dry mass (SDM) and total dry mass (BIO). To evaluate the development of Jacaranda mimosifolia plants, the experiment was conducted in a greenhouse, wherein the soil of each pot (10 L) was treated with five strains of the Trichoderma spp. (Trichoderma asperellum URM 5911; T. harzianum ESALQ 1306; T. harzianum IBLF 006 WP; T. harzianum SIMBI T5 and T. harzianum T-22 WG. Then, Jacaranda mimosifolia seeds were sown and the evaluations performed at 120 DAS. The variables were: PG at 120 DAS, shoot height (SH), stem diameter (SD), and Dickson quality index (DQI). The strains SIMBI T5, ESALQ 1306 and T-22 WG stood out in relation to RL; while ESALQ 1306 and SIMBI T5 stood out performed the RL and TL. In greenhouse, SIMBI T5 and ESALQ1306 presented higher values of ALT, CR, DC, MFT. Meanwhile, only the SIMBI T5 strain stood out for MSPA, MSR, BIO and DQI. Jules Patrice Ngoh Dooh, Josué Ngando Essoh, Serge Bertrand Mboussi, Alain Heu, William Norbert Kuate Tueguem, Dieudonne Amayana, Oscar Nguidjo, Richard Dongmo, Kaze Fofe, Paul Martial Tene Tayo, et al. Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 364-390; doi:10.5296/jas.v9i2.18553 Abstract: Alternatives to synthetic chemicals are undertaken against phytopathogens. The aim of this work is to evaluate the effect of seed extracts of Thevetia peruviana (Pers.) K. Schum. on Mycosphaerella fijiensis Morelet, fungus responsible for banana black leaf streak disease. Five extracts of T. peruviana, hexane extract (HE), ethyl acetate extract (EAE), acetone extract (AcE), methanol extract (ME) and aqueous extract (AqE), and a fungicide, Azoxystrobin were used. GC-MS of acetone extract was performed. Fifty (50) strains of M. fijiensis per sampling site were tested. Three concentrations of extracts 6.25 (C1), 12.5 (C2), and 25 (C3) μl/ml, a negative control (0 μl/ml) and 10 ppm of azoxystrobin were used for the tests. The MIC50 and MIC90 were determined. GC-MS showed chemical compounds with different molecular height such as acids, sugars, and esters. AcE and AqE significantly reduced M. fijiensis germ tube growth at C2 and C3 concentrations and with inhibition percentage respectively ranged of 60-90% and 40-80%. The growth levels of the germ tubes were above the strobilurin resistance threshold at Njombe and peasant plantation, ranging from 77.9% to 92.3%. AcE showed the same or superior efficacy as the fungicide used on conidial germination at all tested concentrations. The MIC50 totally reducing mycelial growth and conidial germination was 6.25 μl/ml. T. peruviana seeds extracts can be exploited in integrated pests management against M. fijiensis. , Giovani Greigh de Brito, Paulo Roberto Reis Fagundes, Walkyria Bueno Scivittaro, José Maria Barbat Parfitt, Thais Stradioto Melo, Laryssa Barbosa Xavier da Silva, Sidnei Deuner Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 304-322; doi:10.5296/jas.v9i2.18256 Abstract: Breeding programs aim to increase grain yield and quality through selection oriented mostly by morphological and productive traits. Although morphoanatomical traits are preponderant for plant performance, they are usually time-consuming, demanding specific equipment and trained personnel. The aim of the study is to establish relationships among morphological, micromorphological and anatomical traits of rice genotypes, to support rice breeders in choosing variables to be assessed in the search for superior rice genotypes. We assessed morphological (2nd leaf and root lengths, tiller and root number), micromorphological (vein density, intervein distance, stomatal density and opening width) and anatomical (area of sclerenchyma, xylem and phloem vessels, and percentage of aerenchyma) traits. Root number and length, area of sclerenchyma and xylem and phloem vessels are proposed to be the most efficient traits to be assessed in detailed studies aiming to identify superior genotypes in rice breeding programs, from the morphophysiological point of view. Juliana Gress Bortolini, Cláudio Roberto Fonsêca Sousa Soares, Matheus Junckes Muller, Guilherme Wilbert Ferreira, Edenilson Meyer, Caroline Krug Vieira, Monique Souza, Claudinei Kurtz, Cledimar Rogério Lourenzi, Paulo Emílio Lovato, et al. Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 130-150; doi:10.5296/jas.v9i2.18196 Abstract: Crop systems using cover crops affect soil physical, chemical, and biological attributes, including aggregate formation. This work aims to evaluate winter cover crop species' effect on soil total organic carbon, glomalin, and aggregation in areas with onion crops in a no-tillage vegetable production system (NTVS) and conventional tillage system (CTS) for eight years. The experiment treatments were: control, with natural vegetation(NV); black oats (Avena strigosa); rye(Secale cereale);oilseed radish(Raphanus sativus);intercropped black oats and oilseed radish; intercropped rye and oilseed radish; and a conventional tillage systems area. A 33-year old adjacent secondary forest was evaluated as a reference for undisturbed conditions. We assessed soil total organic carbon, total glomalin, and easily extractable glomalin in three soil layers (0-5, 5-10, and 10-20 cm depth). Undisturbed samples were used to quantify soil aggregate stability, aggregation indexes (weighted mean diameter; geometric mean diameter), aggregate mass distribution (macroaggregates, mesoaggregates), and macroaggregate carbon contents. The conventional tillage areas had the lowest weighted mean soil aggregate diameter, geometric mean diameter, and macroaggregate mass. Those areas also had the lowest bulk soil and aggregate organic carbon contents and the lowest total and easily extractable glomalin. Winter cover crops' use resulted in a 10% higher aggregate weighted mean diameter and geometric mean diameter. Areas with cover crops had 13% higher organic carbon contents in aggregates and 17% higher macroaggregate mass than conventional tillage areas. The highest values of total and easily extracted glomalin occurred in plots with black oats. Winter cover crops, single or intercropped, improved physical attributes of soils with onion crops under not-tillage compared to conventional tillage areas. Núbia De Fátima Alves Dos Santos, Jamile Andréa Rodrigues Da Silva, Airton Alencar De Araújo, , , Andréia Santana Bezerra, Benjamim De Souza Nahúm, Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 260-271; doi:10.5296/jas.v9i2.18022 Abstract: This research aimed to study the behavior of female Murrah buffaloes in a silvopastoral system. The trial was carried out at Embrapa Eastern Amazon, under Afi climate according to the Köppen classification, between August and November 2009, during the less rainy season. Three different periods of the day were considered during activity evaluation: morning period – between 6:00 AM and 9:55 AM; intermediary period – between 10:00 AM and 1:55 PM; and afternoon period – between 2:00 PM and 5:55 PM. The animals were maintained in a silvopastoral system (SPS) (ST; n=10) with shade from Racosperma mangium. The meteorological variables of temperature and relative air humidity were measured, as well as the following animal behavior variables: time grazing, ruminating and idling, time standing and lying, and time in shaded and non-shaded areas. These variables were compared by T test (P<0.05). Air temperatures were higher in the non-shaded area of the SPS. All activities were reduced in the intermediary period, except idling. The grazing and rumination times in the morning were longer in non-shaded areas, while the time idling standing was longer during the intermediary period in shaded areas as a way of avoiding the harmful effects of the intense solar radiation and high air temperatures of the Amazonian humid climate. Hence, SPSs may contribute to animal welfare and increase their productive behavior. Rogelho Alexandre Trento, , , Marcio Roggia Zanuzo, , Daniela Ribeiro Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 205-223; doi:10.5296/jas.v9i2.18018 Abstract: The aim of this study was to evaluate the effects of homeopathic medicine Calcarea carbonica 12CH and bioproducts: filtrates of saprobic fungi from Amazon, green propolis nosode 06CH, filtrate of Pichia sp., green propolis extract, Bacillus subtilis; to control Lasiodiplodia (Lasiodiplodia sp.) and development of passion fruit seedlings (Passiflora edulis Sims f. flavicarpa Degener). The experiment was carried out in a completely randomized design with 10 treatments in a parcel divided in time. Each plot consisted of 5 plants for analysis. Data were subjected to analysis of variance and when significant compared by Scott-Knott test (p> 0.05). Variables related to plant growth and the area under the disease progress curve (AUDPC) were evaluated. Assessments were performed at 67, 74 and 82 days after transplantation. There was no reduction in AUDPC for treatments compared to control. As for plant height (cm), the best treatments were Pichia sp. and Gonytrichum sp. with an increase in relation to control of 29.70% and 18.24%, respectively, and increased leaf area (cm2) by 27.42% and 19.85%, respectively. B. subtilis, Pichia sp. and Gonytrichum sp., increased total biomass by 42.31%, 32.82% and 21.44%, respectively. The filtrates application from Pichia sp., Filtrate from Gonytrichum sp., C. carbonica 12CH and B. subtilis provided better performance in the development of passion fruit plants with an increase in the main morphological attributes. The results show that the use of bio products improves the development of seedlings, especially the use of yeast and saprophytic fungi by controlling the biochemical and physiological processes of plants during development. Samuel A. Wyffels, Julia M. Dafoe, Cory T. Parsons, Darrin L. Boss, Timothy DelCurto Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 248-259; doi:10.5296/jas.v9i2.18425 Abstract: This study evaluated the relationships between supplement intake behavior, beef cattle performance, and grazing behavior on dormant northern mixed-grass rangelands. In each of two years, a commercial herd of bred cows grazed a rangeland pasture from November to January. All cattle were managed as one contemporary group. Calf birth date, birth weight, and adjusted 205-day weaning weight were collected for each cow following the grazing season each year as cow performance metrics. During the grazing season, all cattle were provided free-choice access to a self-fed supplement. Supplement intake behavior was measured for each individual. Grazing behavior was monitored for 30 randomly selected individuals. The relationship of individual average daily supplement intake (R = 0.65; ρ = 0.65), supplement consumption rate (R = 0.58; ρ = 0.54), the coefficient of variation of supplement intake (R = 0.51; ρ = 0.50), and the amount of time spent at the feeder (R = 0.47; ρ = 0.49) were positively correlated and ranked across years (P < 0.01), suggesting individual animal supplement intake behavior is repeatable for cattle grazing dormant season rangelands. Additionally, there were multiple significant associations between supplement intake behavior, cattle performance, and grazing behavior (P ≤ 0.05); however, the majority were weak associations that accounted for minimal variation in cattle performance and grazing behavior (R ≤ 0.27; r2 ≤ 0.07). Although supplement intake behavioral traits were repeatable across years, its use as a metric to predict animal performance and grazing behavior may be limited. Simone Bernardes Voese, Marcia Maria Dos Santos Bortolocci Espejo, Mariana Planells Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 421-444; doi:10.5296/jas.v9i2.15155 Abstract: Biofortified foods represent an alternative to minimize extreme and “hidden” hunger in people. Aiming to look at this sector as a business, this study seeks to identify potential demand in the consumer market regarding fortified foods in Brazil. In order to do these, multiple sources of data collection were adopted to access different markets for these products. In the first part of the research a survey of Brazilian government programs was carried out, which could encourage the demand of biofortified foods. In addition a conversation was undertaken with stakeholders seeking to identify the perception of agents who take part in the value chain, which included the project developer in Brazil (Embrapa) to the food industry. Additionally a quantitative research was carried out using Mann-Witney and Chi-square tests, and also Multiple Correspondence Analysis, aiming to evaluate the perception of final consumers regarding biofortified foods. Looking at the results a potential demand was identified for biofortified foods, through government programs as well as via the food industry, despite needing larger promotion amongst the Brazilian population, as the sample showed a considerable lack of awareness. In relation to biofortified foods each market showed different interests, such as Cascavel, Parana, which showed greater interst in School Meals with corn and cassava. While in the food industry the interest was more considerable for sweet potato, and amongst the final consumers there was a bigger interest in corn and beans. A potential demand in several markets for all biofortified foods was also shown. Amelie Baomalgré Bougma, Korodjouma Ouattara, Halidou Compaore, Hassan Bismarck Nacro, Caleb Melenya, Samuel Ayodele Mesele, Vincent Logah, Azeez Jamiu Oladipupo Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 283-303; doi:10.5296/jas.v9i2.18505 Abstract: In the more mesic savanna areas of West Africa, many areas of relatively tall and dense vegetation with a species composition more characteristic of forest than savanna are often found around villages areas. These ‘forest islands’ may be the direct action of human activity. To better understand these patches with relatively luxuriant vegetation, our study focused on how they influence soil aggregation in comparison with nearby areas and natural savanna vegetation across a precipitation transect in West Africa for which mean annual precipitation at the study sites ranges from 0.80 to 1.27 m a-1. Soil samples were taken from 0 to 5 cm and 5 to 10 cm depths and aggregate groups with diameters: > 500 μm, 500-250 μm and 250-53 μm (viz. “macroaggregates”, “mesoaggregates” and “microaggregates”) determined using the wet sieving method. The results showed significantly higher proportion of stable meso and macroaggregates in forest islands and natural savanna compared to agricultural soils (p <0.05). On the other hand, although there was no effect of land-use type on microaggregates stability, there was a strong tendency for the microaggregate fraction across all land use types to increase with increasing precipitation. Soil organic carbon and iron oxides contents are the most important factors influencing aggregate stability in West African ecosystems. By increasing soil structural stability, forest islands contribute to soil erosion reduction and the control of land degradation. Tainára Cunha Gemaque, Sérgio Rodrigues Da Silva, Daniele Salgueiro De Melo, Daniel Pereira Da Costa, Kleber Campos Miranda Filho Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 347-363; doi:10.5296/jas.v9i2.18162 Abstract: Medicinal plants from Amazon have been commercialized for decades, but few scientific studies prove their effectiveness and safety in use in aquaculture activities. The objective of the present study was to use the Amazon river prawn Macrobrachium amazonicum to predict the toxicity of the natural extracts of nine medicinal plants viz pariri Arrabidaea chica, muirapuama Ptychopetalum olacoides, anauerá Licania macrophylla, barbatimão Ouratea hexasperma, faveira Vatairea guianensis, sacaca Croton cajucara, jacareúba Calophyllum brasilliense, pau d’arco Tabebuia sp. and verônica Dalbergia subcymosa, in concentrations of 1, 10, 100, 500 and 1000 µg/mL. The media was prepared in 0.5% dimethyl sulfoxide (DMSO) diluted with water. Ten post-larvae (0.5 ± 0.1 g) were added to each triplicate and, after 24 h, the mortalities were evaluated, with the results of median lethal concentration expressed as LC50-24h using the Probit statistical method. To obtain the concentrations of a common bioactive compound of plant extracts, the concentrations of flavonoids were analyzed using a methodology based on the formation of chromophores. The results of acute toxicity indicate variability in the toxic effects of medicinal plants, taking into account the concentration of total flavonoids, with the least toxic Tabebuia sp. (LC50 = 758.31 µg/mL) and the most toxic C. cajucara and V. guianensis (LC50 = 72.16 and 75.23 µg/mL), respectively. The extracts demonstrated lethality against M. amazonicum, which predicts toxicity and warns of its use them as herbal medicines. More studies must be carried out to determine other bioactive compounds in the plant extracts used since there is an unparalleled availability of chemical diversity. Joseph Yohane Issa, Arnold Onyango, Anselimo Makokha, Judith Okoth Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 406-420; doi:10.5296/jas.v9i2.18424 Abstract: Vegetables provide nutrients, especially minerals and vitamins, and non-nutrient phytochemicals with health benefits. Iron, zinc and vitamin A deficiencies are common in most developing countries yet traditional vegetables that can provide these nutrients grow wildly in most areas. This study evaluated the nutrient contents, phytochemicals and the 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activities of five traditional leafy vegetables grown in Malawi, namely Amaranth hybridus (Amaranth ssp.), Moringa oleifera ( Drum stick), Bidens pilosa (Black jack), Corchorus olitorius (Jute mallow) and Ipomea batatas (Sweet potato) leaves. Results from the present study show that beta-carotene ranged from 829.68 µg/100g to 5,791.64 µg/100g and Moringa oleifera had the highest concentration. Vitamin C content ranged from 7.93 mg/100g to 35.81 mg/100g and Ipomea batatas leaves had the highest concentration. Zinc concentrations ranged from 4.42 mg/100g to 10.59 mg/100g. Iron content ranged from 37.22 mg/100g to 48.21 mg/100g. Total phenolics content (TPC) ranged from 0.98 g/100g to 3.89 g/100g with Bidens pilosa leaves having the highest TPC (3.89±0.23 g/100g). Moringa oleifera and Bidens pilosa leaves had significantly higher (P Corchorus olitorius > Moringa oleifera > Ipomea batatas > Amaranth hybridus. The 50% inhibitory concentration (IC50) values of these vegetables ranged from 12.5 µg/mL to 125 µg/mL. Lower IC50 values indicate higher radical scavenging activity. The results suggested that the traditional vegetables under the study can significantly contribute to improved human nutrition and have potential to reduce diseases related to oxidative stress. Bruno Machado Araújo, Anatércia Ferreira Alves, Paulo Alexandre Fernandes Rodriques de Melo, Leonardo Hunaldo dos Santos, Mário Luiz Ribeiro Mesquita Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 471-487; doi:10.5296/jas.v9i2.18503 Abstract: This study evaluated the soil seed bank’s germination potential and density in five distinct environmental areas namely: a) regenerated forest, b) secondary forest, c) degraded pasture, d) Eucalyptus sp. plantation and e) fallow corn growing area, with a view to regenerate forests in Western Amazonia using tray germination methodology. We assessed floristic similarity and diversity using the Jaccard Similarity Index and the Shannon Diversity Index, respectively. We computed each species’ phytosociological parameters: density, frequency and importance value of each species. We recorded a total 3674 individuals from 51 species and 21 families. The families with the highest species richness were Asteraceae, Malvaceae, Cyperaceae and Poaceae that contributed to 43% of the total species observed. The most important species computed in the phytosociological analysis were Chamaesyce hirta, Corchorus aestuans, Cyperus iria and Chamaesyce prostrata. All species had a herbaceous life form, which in the literature, are considered weeds. We documented the largest number of individuals in the fallow corn growing area that had 3620 plants m-2 and the smallest number in the regenerated forest that had 183 plants m-2. We observed the greatest floristic similarity between the secondary forest and Eucalyptus sp. plantation (40%), and the greatest floristic diversity in the Eucalyptus sp. plantation (H '= 2.59 nats individual-1). In conclusion, the transposition of the soil seed bank is not recommended for forest regeneration and recovery in degraded areas due to massive weed predominance in the soil seed bank. Márcio Paulo de Oliveira, Franciele Buss Frescki Kestring, Jerry Adriani Johann, Miguel Angel Uribe-Opazo, Luciana Pagliosa Carvalho Guedes Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 224-247; doi:10.5296/jas.v9i2.18274 Abstract: Demand for quality weather forecasts has increased in the last decades, leading national meteorological centers to develop new forecasting models. These models have parameterizations which can produce different predictions for the same location and agrometeorological variable. In the state of Paraná - Brazil, studies on rain forecasting are important for planning the soybean crop. The objective of this study was to compare, based on a gold-standard and using bootstrapping residuals, forecasts of total rainfall by virtual stations of the following centers: Canadian Meteorological Center (CMC), European Center for Medium-Range Weather Forecasts (ECMWF), National Centers for Environmental Prediction (NCEP) and Center for Weather Forecasting and Climate Studies (CPTEC). Gold-standard measurements were obtained from Meteorological System of Paraná (SIMEPAR) meteorological stations. The studied region was the state of Paraná, in October–March of the harvest years 2011/2012–2015/2016; forecast ranges were 24 and 240 hours. Knowledge Discovery in Databases (KDD), focused on data mining techniques, was the chosen methodology. In the data preprocessing stage, spatial and temporal stratification, cleansing and grouping were performed. For the comparisons, 24 h and 240 h weather forecasts were used, being grouped in five-day and ten-day periods, respectively, and coefficients of agreement with the gold-standard measure were calculated. The choice of forecast center should consider the geographic location of a certain pluviometric station, and the temporal range of the forecast, according to its measure of agreement with the gold standard measure. Spatial variations of forecasting centers were identified within the mesoregions, which suggests the employment of different forecasting centers in a certain mesoregion. Jacir João Chies, Helvio Debli Casalinho, Lizete Stumpf, Marília Alves Brito Pinto, Leonir Aldrigui Dutra Junior Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 96-112; doi:10.5296/jas.v9i2.18230 Abstract: Farmers' local knowledge about soil quality and management practices should be considered to assess the impact of agricultural technology packages on the environmental performance of agro-ecosystems. This study aimed to evaluate the soil quality under agroecological production in southern Brazil, which was considered of good quality by the farmers' perception. From August to November 2017, ten farms from Liberdade settlement were visited, and semi-structured interviews were conducted to collect information about soil and agricultural knowledge. “What does good quality soil mean? What cares for preserve soil quality? Does the soil location in landscape influence conservation practices?” were the questions asked. In May 2018, soil samples were collected from each area, and chemical, physical, and biological attributes were determined. All farmers mentioned the organic matter indicated good soil quality; however, the study showed that most soils have low content, a consequence of the annual tillage adopted by all farmers for the implantation of seeds crops; Farmers indicated that a good quality soil has "life" with the presence of organisms. In our study, a low population of mites and springtails in most areas was observed. Positive farmers’ perception about the organic matter content and soil organism’s presence in their agroecological production areas come from the degradation history of the areas, at the same time that they attribute improvements in soil quality due to the actions adopted over the 10 years of agroecological production. , , Jose Maria Tarjuelo Martin- Benito, , Alfonso Dominguez Padilla Published: 25 January 2021 Journal of Agricultural Studies, Volume 9, pp 113-129; doi:10.5296/jas.v9i2.18088 Abstract: The present study aimed to validate the MOPECO crop simulation model and to determine a viable irrigation management for watermelon in the semiarid region of Northeast Brazil, using methodologies of optimized regulated deficit irrigation (ORDI) and constant deficit irrigation (CDI). The experiment was carried out during October to December 2013 and the second one from July to August 2014 in plots of land of producers in the Baixo Acaraú Irrigated Perimeter – Ceará, Brazil. Treatments were characterized by ORDI management (70, 80, 90% ETa/ETm ratio) and CDI management along the entire cycle (70, 80 and 90% ETm) and control treatment, irrigated with 100% of the water requirement of the crop (ETm). In terms of saving of water resources, the results showed that management with regulated deficit irrigation leads to favorable and economically viable results for the farmer, of water saving, especially in a situation of severe water scarcity, irrigation management with regulated water deficit (ORDI) can provide favorable and economically viable results for the farmer. The highest value of WUE (41.8 kg m-3) was obtained with the treatment of lowest water volume applied (352.1 L) in the second experiment, decreasing with the increase in the water volume used. The ORDI methodology represents a better water use efficiency for all treatments of deficit applied compared to CDI treatments. The difference of ORDI and CDI methodology provided an increase of up to 200% in the gross margin obtained with the exploration of the watermelon culture which represents a range of R$ 986.00 in profit in a situation of water scarcity, as in the case of the studied region, the strategy with water supply of 70% of ETa/ETm ratio regulated by phenological stage was recommended in order to obtain highest water use efficiency.
Beatriz De Oliveira Lopes, Caroline Correa de Souza Coelho, Aparecida das Graças Claret Souza, Otniel Freitas-Silva
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 286-302; doi:10.5296/jas.v9i1.18050

Abstract:
The Amazon region contains the world’s leading genetic reserve of native plants, with most of the area located in Brazil. This region is rich in species that little known or still unknown by the population at large, including species that produce non-timber forest products (NTFPs) such as edible nuts. The objective was to verify the occurrence of these edible nuts in Brazil, to evaluate their potential and the possibility of other uses, in addition to expanding the knowledge about them. A bibliographic review of the last 50 years was carried out, mainly using the descriptors the popular name and the scientific name of the four nut trees present in the Amazon and their respective families, namely: agouti nut (Acioa edulis Prance) and egg nut (Acioa longipendula Pilg.) From the Chrysobalanaceae family, and sapucaia nut (Lecythis Pisonis Miers) and Brazil nut (Bertholletia excels Bonpl.) From the Lecythidaceae family. The Chrysobalanaceae has 450 species and 17 genera of woody plants and shrubs, producing oilseeds by some species, including egg and agouti nuts. The Lecythidaceae, on the other hand, has approximately 17 genera and 300 species, and in Brazil it is possible to find 9 genera and 122 species, 54 of them endemic, some of which produce edible seeds such as sapucaia and Brazil nuts. Those species have a great nutritional potential, and the chemical composition of their nuts reveals a good amount of lipids and proteins, but more in-depth research on the subject is necessary, including on other biases for better knowledge of the species, discovery of other potential uses and benefits and, consequently, their valorization.
, Nicolae Cruceru, Mircea Negru
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 1-13; doi:10.5296/jas.v9i1.17916

Abstract:
Soils represent that superficial deposit from the land surface in a continuous evolution, but with a high vulnerability to climate change and anthropogenic interventions. The current soil was born in a long period of time (numbering hundreds of years) through pedogenetic factors and processes, but also anthropogenic influences on the parent material.The purpose of this article is to investigate the soil on the territory of a Roma village (vicus), located on both sides of the Caracal Municipality Ring Road. This is located near the Roman road from Romula (Resca village, Dobrosloveni commune, Olt County), the residence of the Dacia Inferior (Malvensis) Roman province’s governor and Sucidava (Corabia-Celei, Olt County), in a region where there was a fertile land favourable to agriculture.The parental materials (carbonate loess-like deposits loamy-clayey loam) belonging to that period are well represented in the soil horizons starting 25-30 cm from the surface to a variable depth, a fact which will be validated by on-going geophysical studies. The dominant soil is argic chernozem, belonging to the cernisols class specific to the plain area, but with a higher amount of clay. It is important to note that in the 4 soil profiles analysed in detail we find differences in soil texture within the horizons, even if there are traces of the Roman period.
Gustavo Moratelli, , Hiago Canavessi, Emerson Fey, Marcos Antonio Sedrez Rangel, Neumarcio Vilanova Da Costa
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 91-111; doi:10.5296/jas.v9i1.17879

Abstract:
The development of cassava varieties with more efficient nutrient absorption can prevent losses caused by weed competition. The objective of this study was to evaluate dry matter accumulation and leaf nutrient content in traditional and improved cassava varieties, with and without coexistence with weeds throughout the cycle. A randomized complete block design was used in a 2 x 2 x 11 factorial scheme with four replications. The first factor consisted of two varieties (Baianinha and Clone 56-03); the second factor was composed of the conditions with and without coexistence with weeds, and the third factor was 11 harvest periods. Coexistence with weeds reduced leaf contents of N (20.8% and 24.8%), P (26.7% and 4.6%) and K (27.1% and 12.6%) for 'Baianinha' and 'Clone 56-03', respectively. For coexistence with 'Baianinha', the period up to the maximum daily nutrient accumulation rate (N, P and K) ranged from 82 to 99 days after planting (DAP), while for 'Clone 56-03', coexistence in this period ranged from 80 to 88 DAP. The plants from the variety 'Clone 56-03' presented higher total dry mass and root dry mass accumulation, as well as higher leaf contents of N, P and K than the traditional cassava variety 'Baianinha', especially when in coexistence with weeds during the whole cycle.
Samara Dayse Da Luz Ayres, Jackson Silva Nóbrega, Riselane De Lucena Alcântara Bruno, Ademar Pereira De Oliveira, Edna Ursulino Alves, Karialane Da Silva Belarmino, Wellington Souto Ribeiro, Alberício Pereira De Andrade
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 186-201; doi:10.5296/jas.v9i1.17991

Abstract:
Common beans are one of the most economically important legumes in the world. The determination of the ideal harvesting period may coincide with the maximum seed quality and vigor. Thus, the objective was to evaluate the physiology of growth and development of fruits, seeds and seedlings of two cultivars of common beans. To this end, two cultivars of common beans were used: the “Macarrão Trepador” and “Rasteiro Fartura” harvested every five days after anthesis (DAA). The pods were harvested and sent to the laboratory for seed analysis and extraction. In the laboratory, biometric characteristics of fruits and seeds, physiological quality (germination and vigor) and chemical composition of seeds were evaluated. The physiological maturity of “Macarrão Trepador” and “Rasteiro Fartura” cultivars occurred at 35 DAA, during which the seeds had the maximum dry matter and the minimum water content. The chemical composition of the seeds of both cultivars was similar, except for lignin, whose content was higher in “Rasteiro Fartura” cultivar at 25 DAA. The color and dry mass of fruits and seeds, germination percentage, first germination count, germination speed index and average germination time are the indicators that help in determining the physiological maturity point.
Almerinda Amélia Rodrigues Araújo, José Ribamar Gusmão Araújo, , Paulo Roberto Ramalho Silva, Solange Maria França, Lízio Laguna Soares, Anne Caroline Bezerra dos Santos, Mário Luiz Ribeiro Mesquita
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 394-410; doi:10.5296/jas.v9i1.18009

Abstract:
The aim of this work was to evaluate the infestation of Anastrepha species in several fruit tree species and A. alveata in wild plum Ximenia americana L. (Olacaceae), as well as the fruit fly community in a Savannah area using faunal indexes and population fluctuation. For this, we installed McPhail traps and carried out collections at Palmeiras home garden, municipality of São Pedro of Piauí, state of Piaui, northeastern Brazil. We noted high infestation of A. alveata in wild plum, with 144.2 puparia/kg, 216.1 puparia/kg and 321.6 puparia/kg for the years 2014, 2015 and 2016. The infestation indexes of A. obliqua in red mombin (Spondias purpurea) were 146.1 puparia/kg in 2016 and 479.2 puparia/kg in 2017, and in umbu-hog plum (Spondias sp.) 607.3 puparia/kg in 2017, both from the Anacardiaceae family. The species that composed the fruit fly community were A. alveata, A. ethalea (predominant), A. obliqua, A. zenildae (dominant and accessory), A. sororcula, A. fraterculus and Anastrepha sp. (accidental). The population fluctuation of A. ethalea occurred from March to October, while A. alveata presented population peaks in the fruiting of wild plum, between October and December
Flávia Mendes Dos Santos Lourenço, Marco Eustáquio De Sá, Oscar Mitsuo Yamashita, Vinícius Martins Silva, Juliana Trindade Martins, Jéssica Alves De Oliveira, , Renan Furquim Da Silva, , Walmor Moya Peres
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 32-43; doi:10.5296/jas.v9i1.17761

Abstract:
Evaluating seed quality with precision and accuracy is one of the priorities for obtaining high quality material. This study aimed to evaluate whether the variations in the performance of the accelerated aging test, in terms of exposure time and temperature, in the traditional form or in saline solution, would result in an efficient combination to evaluate the physiological quality of thyme seeds (Thymus vulgaris L.). The seeds were submitted to the tests of total germination, germination speed index, first germination count, seedlings emergence, seedling length, seedling dry mass, cold test, electrical conductivity, variations in the conduction of the accelerated aging test and the water content of the seeds was performed after each accelerated aging period. The treatments were the combination of temperatures (36, 38, 40 and 42 ºC), exposure time (24, 36, 48 and 72 hours) and two procedures (traditional and saline), with four replications for each batch. Traditional accelerated aging test at 42 ºC and 24 hours of exposure time, and saline solution accelerated aging test at 38 ºC and 24 hours of exposure time showed sensibility to evaluate physiological potential for thyme seed. For both saline solution and traditional accelerated aging test, the exposition time of 24 hours was efficient to evaluate physiological potential of thyme seeds.
Maria Josiell Nascimento Da Silva, Ahmad Saeed Khan,
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 44-64; doi:10.5296/jas.v9i1.16658

Abstract:
The semi-arid region of Ceará is a Brazilian area that is exposed to long and frequent periods of drought. Water scarcity is a threat to the population’s well-being and agricultural activities. We evaluated the effects of graywater reuse for agriculture on income and sustainability of agricultural production in the municipality of Iguatu, located in the semiarid region of the state of Ceará. It is an important research because it deals with a strategy that aims to reduce farmers’ vulnerability to the lack of water. There are no studies that assess the impacts of water reuse in the region. The propensity score matching technique was applied, and primary data were obtained by interviewing beneficiaries (treated group) and non-beneficiaries (control group). The results showed that the program has effects on sustainable agricultural production of small farmers because of the use of non-aggressive agricultural practices. In the group of beneficiaries, the income is 21.9% higher than of that in the group of non-beneficiaries. In addition, families that adopt water reuse have 26.8% higher levels of sustainability than those that do not adopt this strategy of living with drought.
Rosária Da Costa Faria Martins, Rogério Gomes Pêgo, Eleandro Silva Da Cruz, Mateus Marques Bueno, Daniel Fonseca De Carvalho
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 303-319; doi:10.5296/jas.v9i1.17996

Abstract:
The quality of floral stems depends on a set of pre-harvest factors which can influence their postharvest longevity. Although the identification of visual signs of senescence through scales is decisive in assessing the loss of floral quality in the postharvest period, this scale does not exist for zinnia flowers (Zinnia elegans Jacq.). Thus, the objectives of this study were to evaluate the effect of different irrigation levels and growing seasons on the postharvest longevity of zinnia floral stems; and to determine a senescence scale to assess their durability. Therefore, zinnia plants (cv. “Red California Giant”) were cultivated in pots inside a greenhouse in Seropédica (Rio de Janeiro, Brazil), with a randomized block design, under four irrigation levels (46%, 64%, 75% and 100% of the species’ water requirement) and two cycles (autumn-winter and winter-spring). At the end of each cycle, 48 stems from each treatment were harvested and placed in containers holding 300 mL of supply water. For all irrigation levels and crop cycles, there was an increase in the fresh stem weight on the first days after harvesting and the water absorption rate was higher on the first day of evaluation. The proposed senescence scale allowed us to evaluate the loss of floral quality in the postharvest period. The stems from both cycles had satisfactory results, mainly of commercial longevity and the score 5 on the scale, which represents 100% of the stems’ market value. The main postharvest results of the zinnia floral stems were not influenced by the irrigation levels.
, Francisco Sandro Rodrigues Holanda, , , Marks Melo Moura,
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 146-172; doi:10.5296/jas.v9i1.17938

Abstract:
Several plant species have been studied as reinforcement elements against landslides at slopes, either to protect against the splash effect offered by shoots or anchoring the soil by the root system. The objective of this work was to investigate the influence of roots from shrub species over the soil mechanical attributes such as cohesion and angle of internal friction at the São Francisco riverbank, northeastern Brazil. A trench was excavated under the treetop of every shrubby individual, sampling blocks at 0-0.25, 0.25-0.50, 0.50-0.75, and 0.75-1.00 m depths. The moisture contents, particle size, liquidity limits, plasticity and actual specific mass of the samples were determined. The soil physical and mechanical attributes such as initial and final specific weight, initial and final void content, initial and final degree of saturation, shear resistance peaks, cohesion, and internal friction angle were identified through direct, elementary, consolidated, and undrained tests. In the samples with Solanum paniculatum, Mimosa pigra species, the highest values for cohesion were registered for the samples with roots. Sesbania virgata presented the greatest variation in cohesion and internal friction angle among samples with and without roots. The position and root status influenced the results of the direct shear tests.
Wagner Barreto Da Silva, Vanessa Vieira Lourenço-Costa, Higo Otávio Brochado Campos, Wânia Mendonça Dos Santos, , Jamile Andréa Rodrigues Da Silva,
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 268-285; doi:10.5296/jas.v9i1.18059

Abstract:
Buffalo milk has a high nutritional value, with high fat, protein, and mineral levels. Its derivatives yield exceeds by 40% those derived from bovine milk. As a way to take advantage of this quality, Greek yogurt (Labneh) is an alternative to add value to this important product. Thus, this work aims to prepare Greek yogurt with buffalo milk, added with açaí jelly (Euterpe oleracea Mart.), to carry out physical-chemical, microbiological, sensory, and texture profile analyzes in buffalo milk, Greek yogurt, and in açaí jelly. Natural Greek yogurt had an acceptability index of 90.11% and Greek yogurt with açaí jelly, 93.11%, which constitutes an alternative for regional raw material valorization, with excellent acceptability, high nutritional value, and outstanding physical-chemical and microbiological quality. Thus, this derivative is indicated for special programs supported by the City Halls and/or Government of Pará state, as a way of generating income and employment for communities producing buffalo milk and açaí.
Letícia Ellen Dal Canton, Luciana Pagliosa Carvalho Guedes, Miguel Angel Uribe-Opazo
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 357-376; doi:10.5296/jas.v9i1.17473

Abstract:
Financial investment with collection and laboratory analysis of soil samples is an important factor to be considered when mapping agricultural areas with soybean planting. One of the alternatives is to use the spatial autocorrelation between the sample points to reduce the number of elements sampled, thus restricting the collection of redundant information. This work aimed to reduce the sample size of this agricultural area, composed of 102 sample points, and use it to analyze the spatial dependence of soil macro- and micro- nutrients, as well as the soil penetration resistance. The agricultural area used in this study has 167.35 ha, cultivated with soybean, which the soil is Red Dystroferric Latosol, and the sampling design has used in this agricultural area is the lattice plus close pairs. The reduction of the sample size was made by the multivariate effective sample size (ESSmulti) methodology. The studies with the simulation data and the soil attributes showed an inverse relationship between the practical range and the estimated value of the univariate effective sample size. With the calculation of ESSmulti, the sample configuration was reduced to 53 points. The Overall Accuracy and Tau concordance index showed differences between the thematic maps elaborated with the original and reduced sampling designs. However, the analysis of the variance inflation factor and the standard error of the spatial dependence parameters showed efficient results with the resized sample size.
Richard Williams
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 455-456; doi:10.5296/jas.v9i1.18554

Abstract:
M. H. Rashid, A. K. M. Aminul Islam, M. G. Rasul, M. M. H. Saikat, J. U. Ahmed
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 426-439; doi:10.5296/jas.v9i1.18026

Abstract:
Selected eight inbreed line were used in crossing as half diallel fashion to find out different genetic parameter as well as targeting superior combination for hybrid vigour. Sunflower first introduce in Bangladesh 1980 by Bangladesh Agricultural Research Institute and Mennonite Central Committee. BARI Sunflower-1(Kironi) and BARI Sunflower-2 is only two released variety. But major obstacles for sunflower cultivation are both varieties are more than 1.50m height and require > 100 days for maturity. As this country is facing climate change unfavorable weather, sunflower cannot withstand in stormy weather. Specially at the time of prematurity stormy weather causes lodging due to over height, it is essential to develop dwarf stature plant. Due to strong crop competition in winter it cannot fit in major cropping pattern T-Aman-Mustard-Boro due to it long duration. Bangladesh has accessible land of 0.85 million hectares in saline areas (Banik et al., 2011). These lands can be used for sunflower cultivation as it is moderately saline tolerant (Rahman et. al. 2018). On the other hand in different part of Bangladesh (e.g. Cumilla, Manikgonj, Sherpur, Jamalpur, Netrokina, Tangail, Dinajpur, etc.), a huge amount of lands are kept fellow after T. Aman harvest. These current fellow lands can be easily used by sunflower cultivation if short duration varieties are available. Both plant height and days to maturity were considered as favorable for negative heterosis to obtain dwarf plant stature and short duration plant to fit in existing cropping pattern in Bangladesh. Positive heterosis is considered desirable for other yield contributing traits. The hybrid HE15, HE17 and HE16 showed significant negative heterosis both for mid parent and better parent. Negative heterosis for plant height is desirable to adopt hybrid in unfavorable weather condition. The Hybrid HE15 showed both for significant negative mid parent and better parent heterosis. High heritability along with significant mid parent and better parent heterosis indicate scope of utilization of hybrid as commercial and further use in breeding programmes. Several outstanding cross combinations, HE17, HE16, HE14, HE15, and HE18 showed significant and desirable heterosis for seed yield per plant over mid parent and better parent. The hybrid combinations HE17, HE16 and HE14 could be utilized to exploit the heterosis as well as commercial multiplication of seed to get direct benefit by the farmers.
Clotilde Gnon Bio N’GOYE, Janvier Egah, Mohamed Nasser Baco
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 173-185; doi:10.5296/jas.v9i1.17940

Abstract:
Agriculture in Benin is confronted with new problems which require more sustainable and resilient strategies for its development. The question of its sustainability is thus at the center of agricultural policies. This study analyzed how issues of sustainability of farming systems are taken into account in argicultural policies frameworks. An analysis and review of the four main agricultural policy documents adopted over the last thirty years being completed to assess the measures taken to ensure the sustainability of farms. It emerges that agricultural policies do not integrate into their framework the pillars on which the development of sustainable agriculture is based. However, in their implementation, they have been strongly oriented towards the pursuit of economic and social objectives, which is reflected in the will to improve the productivity and attractiveness of the agricultural sector. However, the lack of long-term strategies, the lack of coherence between policies and the dependence on the international political context has not allowed interventions in the agricultural sector to be placed in a sustainable perspective.
Laures Francisco Cieslik, Paulo Cesar Conceição, Jaqueline Pereira Machado De Oliveira, Ana Regina Dahlem Ziech, Lizete Stumpf, Leandro Alves De Freitas
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 65-76; doi:10.5296/jas.v9i1.17774

Abstract:
This study aimed to determine the dry biomass and nitrogen accumulation, the height and stem diameter of corn crop preceded by different leguminous cover crops, under different nitrogen doses. The study was conducted in the experimental area of Federal Technology University of Paraná, in Dois Vizinhos. The eigth cover crops consisted on: Sunn hemp; Crotalaria spectabilis; Jackbean; Cajanus cajan; Dolichos lablab; Velvet beans; Black velvet beans and Spontaneous species. The two dose nitrogen fertilization included: zero kg N ha-1; 180 kg N ha-1 applied in a single dose, under conditions of adequate humidity, 47 days after corn seeding. Were evaluated the height, dry biomass and basal stem diameter corn and the decomposition and release of N from the cover plants. The use of leguminous before corn crop is a good option for the southwest region of Paraná because it promotes soil protection and can promote increased carbon stock in the environment. The leguminous cover crop should be used like green manure, making them important species in the Brazilian agriculture sustainability context, once there are evidence of reducing or even not using mineral nitrogen fertilization in the subsequent agricultural crops, mainly the Jackbean.
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 14-31; doi:10.5296/jas.v9i1.17758

Abstract:
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used in several countries. Research on the neurotoxicity of 2,4-D has been focused on the central nervous system, and little is known about its effects on the myenteric plexus. Therefore, to elucidate the neurotoxicity of 2,4-D and the viability of its use, we investigated the effects of daily intake of 5 mg 2,4-D/kg for 60 days on the myenteric plexus neurons of the rat ileum using quantitative and morphometric analyses. Twenty male Wistar rats aged 60 days were divided into two groups (n=10 rats/group). The group E animals received daily 5 mg doses of 2,4-D/kg diluted in 1 mL of water, whereas the group C animals were not treated with the herbicide. The animals were euthanized with anesthetic after 60 days; subsequently, the ileum was dissected out, and procedures were performed to visualize the total population of neurons (Giemsa staining), the nitrergic neurons (NADPHd+), and the estimated population of cholinergic neurons (NADPHd-). The results were statistically analyzed and compared between groups. In group E, the densities of Giemsa-stained neurons and NADPHd- neurons decreased (p
João Manoel da Silva, Yamina Coentro Montaldo, Arthur Costa Pereira Santiago de Almeida, Viviane Araújo Dalbon, Juan Pablo Molina Acevedo, Tania Marta Carvalho dos Santos, Gaus Silvestre De Andrade Lima
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 411-425; doi:10.5296/jas.v9i1.18321

Abstract:
The rhizosphere is the region that has direct influence from the roots. This is the place where most of the interactions between microorganisms and plants occur. Studies involving the ecology of microbial communities from the rhizosphere became more frequent after the first reports of biological interactions of microorganisms with plants that influence physically and chemically modify the soil surrounding. According to these hypotheses, the rhizosphere mycobiota provides the development of plants through various mechanisms, direct and indirect. Thus, the objective of this review was to explain the aspects that provide characterizing these microorganisms as beneficial to plants in view of their applicability to agro-ecosystems. Therefore, it is stated that rhizospheric fungi have the solubilization of phosphorus (P), assimilating this nutrient for plants, promoting growth through the production or stimulation of the production of growth regulators such as 3-indole acetic acid, and control of phytopathogenic agents such as other filamentous fungi, and also phytonemamatodes. Therefore, it is possible to observe the importance of the constant observance of the action of these microorganisms in terms of their ecological role due to the agro-ecosystem.
José Maria Filippini Alba, Carlos Alberto Flores, Alberto Miele
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 440-454; doi:10.5296/jas.v9i1.18320

Abstract:
The purpose of this study was a comparison of soil parameters among superficial and sub-superficial horizons of three representative type of soils in Vale dos Vinhedos, Brazil, aiming Viticulture in general, but Precision Viticulture (PV) management as specific focus. Basic aspects of Viticulture or PV are still discussed, by instance, sampling procedures, influence of pedology on quality of wine or methods for defining the management zones. Samples were collected according to each horizon, superficial (0-20 cm in depth) or sub-superficial (>40 cm in depth), that is, A (all soils), A2 (Neossolo), Bi (Cambissolo), or Bt (Argissolo). Micro-vinification was performed for grapes derived from five classes of soil. The pedological parameters analyzed were granulometric fractions, chemical parameters and degree of flocculation. Data were organized according to a Geographic Information System (GIS) by ten classes of soil. Basic statistical analysis, line graphs, XY plots and factor analysis were used to interpret the physicochemical variables related to horizons, soil and wine. Relative Accumulation Indexes were evaluated for horizons of soil, classes of soil and wine. Data organized by horizon and type of soil showed great dispersion, so outliers were discarded and data organized by class of soil. Correlation of data related to soil horizons, A against A2/B, was evident for macronutrients. Micro-vinification altered content of K and P in wine. Relative Accumulation Indexes of soil horizons correlated to declivity, when declivity lesser than 20% occurred. Fe and Zn showed correlation among sub-superficial horizon and wine for some classes of soil.
Assan Gnoumou, Raymond Nana, Edith Marie Sylvie Daboué, Amadé Ouédraogo
Published: 20 January 2021
Journal of Agricultural Studies, Volume 9, pp 249-267; doi:10.5296/jas.v9i1.18198

Abstract:
In Burkina Faso, medicinal plants are used mainly by the most vulnerable populations (70%). This study aims to promote the ex-situ reproduction of Flemingia faginea to make it accessible as a remedy for high blood pressure. Sexual reproduction of Flemingia faginea was carried out to evaluate the effect of 2 pre-germination treatments on the seeds’ germination rate. One pre-germination treatement included soaking seeds in tap water for 24h (T1), another soaking in boiling water until cooling for 24h (T2) while the control experiment did not have any pre-germination treatments (T0). We used seeds from two provenances: North-Sudanian (NS) and South-Sudanian (SS). The germination percentage and mean germination time (MGT) were calculated; additionally, the seedling height, diameter, leaves production were monitored for 2 months. The variance analyses fit to tukeys tests were used to compare the effects of the various treatments on germination rate, mean germination time and seedling growth. The best germination rate was obtained with T0 (96% NS and 79% SS). The best mean germination time (MGT) was 7.25 days T2. The best seedling growth was obtained with T0 and T1 (P=0.000). As the provenance is concerned, the NS provenance was the best source for germination capacity, for the best seedling growth. A test using seeds from NS combined at T0 conditions provides optimal conditions for production of F. faginea at almost no cost to the local population.
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