Australian Journal of Crop Science   AJCS

Chemical composition and seasonal variation of the essential oils of leaves of Garcinia gardneriana (Planchon & Triana) Zappi (Clusiaceae)

Carla Maria Mariano Fernandez*, Fabiana Brusco Lorenzetti, Camila Cristina Iwanaga, Karine Zanoli Bernuci, Ludmila Pini Simões, João Paulo Pinguello de Andrade, Wanessa de Campos Bortolucci, José Eduardo Gonçalves, Diógenes Aparício Garcia Cortez, Zilda Cristiani Gazim, Benedito Prado Dias Filho

Postgraduate Program in Pharmaceutical Sciences, State University of Maringá (UEM), Maringá, Brazil; 2Unicesumar, Maringá, Brazil
Postgraduate Program in Chemical Engineering, Western Parana State University-(UNIOESTE), Toledo, Brazil 4Postgraduate Program in Biotechnology Applied to the Agriculture, Paranaense University, Umuarama, Brazil
Postgraduate Programs in Clean Technologies, Cesumar University, Maringá, Brazil
Cesumar Institute of Science, Technology and Innovation – ICETI, Maringá, Brazil

Abstract
The seasonal factors have influence upon the secondary metabolism of plants in adaptive response to the environmental variation, leading to the biosynthesis of different compounds. Thus, the aim of the present paper was to characterize the chemical composition of the essential oil (EO) from leaves of Garcinia gardneriana (Clusiaceae), in function of the seasonality, in the period throughout the year (from January to December of 2016). The EO was obtained from fresh leaves by hydrodistillation in a modified Clevenger apparatus and analyzed using a gas chromatograph coupled to a mass spectrometer. Thereafter, the chemical constituents of the EO were evaluated by principal component analysis (PCA) and hierarchical cluster analysis (HCA). The EO yield varied differently throughout the year with the highest yield in January (0.38%) and the lowest one in August (0.19%). The EO composition was sesquiterpene hydrocarbons (84.78 - 99.07%) and oxygenated sesquiterpenes (0.45 - 13.80%). The major compounds found were α-cedrene, for the months of January to November, and α-trans-bergamotene for December. PCA and HCA analyses showed that the development stage of the plant may have altered the chemical composition of the EO, since in the flowering period the compounds α-trans-bergamotene and γ-muurolene were higher, which are responsible for attracting pollinators and for the plant’s defense. Moreover, in the fructification period, the production of compounds of the oxygenated sesquiterpenes class, namely (Z)-caryophyllene, sphatulenol and caryophyllene oxide increased (13.80%), what is probably related to the protection of the fruit. Thus, the EO of “bacupari” leaves had high chemical variability, which is likely related to the developmental cycle of the plant.

Pages 1-8 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.1800
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Effects of composted swine manure on nutrient content in grains of Panicum miliaceum L.

Dionei Schmidt Muraro*, Fabiana Lima Abrantes, Claudir José Basso, Fabio Lima Abrantes, Vanessa Alba da Silva, Adalin Cezar Moraes de Aguiar, Ivan Ricardo Carvalho, Henrique Pozebon, Marcia Gabriel, Marco Eustáquio de Sá, Stela Maris Kulczynski

Department of Entomology and Acarology, University of São Paulo (ESALQ/USP) – Piracicaba, São Paulo, 13418-900, Brazil
Departmentof Agronomy College, University of Oeste Paulista (UNOESTE), Raposo Tavares Highway Km 572, Presidente Prudente, São Paulo 19067175, Brazil
Department of Plant Protection, Federal University of Santa Maria (UFSM), Roraima Avenue 1000, Santa Maria, Rio Grande do Sul 97105900, Brazil
Department of Plant Science, Food Technology and Economy Partner, São Paulo State University Julio de Mesquita Filho (UNESP), Monção Street 226, Ilha Solteira, São Paulo 15385-000, Brazil
Department of Plant Science, Federal University of Viçosa (UFV), Avenida Peter Henry Rolfs, Viçosa, 36570-900, Brazil
Department of Agrarian Sciences, Regional University of Northwestern Rio Grande do Sul, 98700-000, Brazil

Abstract
The aim of this work was to evaluate the effect of different doses of composted swine manure on protein and macronutrient contents of proso millet grains and in nutrient export by the crop. The experiment was carried out in the years 2013 and 2014 in a randomized block design, with four replications and five treatments, composed of four doses of composted swine manure (0, 4.0, 8.0 and 12.0 Mg ha-1) and one dose of mineral fertilization (NPK 100-60-40 kg ha-1). Compost and mineral fertilizers were applied manually in each plot after the sowing of the crop, according to the established doses. After the harvesting, grain samples were taken to determine protein, N, P, K, Ca, Mg and S contents, as well as the amount of macronutrients exported by the crop. The data were submitted to analysis of variance. The means of the variables related to the compost doses were compared to the control plot (absence of fertilization) and to the mineral fertilization plot using the Tukey’ test (P≤0.05), and the effects of CSM doses were assessed by regression analysis, adopting as selection criteria the model and the magnitude of the regression coefficients at 5% of significance. The export of nutrients from the field by P. miliaceum grains at the dose of 4.0 Mg ha-1 of compost was equal to the mineral fertilization recommended for the crop, justifying the use of swine manure as a substitute for mineral fertilization. The use of compost provides protein content in P. miliaceum grains similar to the use of mineral fertilizer.

Pages 9-15 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.1942
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Sowing speed can affect distribution and yield of soybean

Luan Felipe Bortoli, Guilherme de Almeida Arismendi, Matheus Martins Ferreira, Thomas Newton Martin*

Universidade Federal de Santa Maria, Santa Maria – RS, Brazil

Abstract
The sowing speed or planting speed is referred to tractor and seeder displacement speed during the sowing. It plays a crucial role intruding distribution of plants, and consecuently yield of soybean grain. Therefore, this paper endeavors to corroborate the repercussions of the sowing speeds on the plants distribuition and grain yield. The experimental design consisted of a randomized complete block design with five treatments and four replications, with the treatments comprising of five sowing speeds (2.0, 3.1, 6.1, 7.4, 9.0 km h-1). The following parameters were evaluated:(i) distance between plants, (ii) double spacing, acceptable spacing and failing spacing, (iii) number and dry mass of nodules, (iv) plant population, (v) shoot dry mass, (vi) mass of one thousand grains, and (vii) grain yield. With the increase in the sowing speed, the equidistance of plants in the row was changed, which in turn decreased the soybean yield. The results showed that seeding speeds close to 4.0 km h-1 provided better uniformity and distribution of plants in the row. The results also unveiled that sowing speed mainly influence the plants distribution, having greater influence on the productivity components, thereby affecting the overall soybean grain yield.

Pages 16-22 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2238
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Sustainable optimization of nitrogen uses in oat at sowing and top-dressing stages

Douglas C. Reginatto, José Antonio Gonzalez da Silva, Roberto Carbonera, Cleusa Adriane Menegassi Bianchi, Felipe Libardoni, Adriana Roselia Kraisig, Ivan Ricardo Carvalho*, Juliana Aozane da Rosa, Cibele Luisa Peter, Natiane Carolina Ferrari Basso, Júlio Daronco Berlezi, Felipe Uhde Porazzi

Departament of Exact Science and Engineering, Regional Northwest University of Rio Grande do Sul, 3000 Comércio Street, Ijuí, RS, 98700-000, Brazil
Departament de Estudos Agrários, Regional Northwest University of Rio Grande do Sul, 3000 Comércio Street, Ijuí, RS, 98700-000, Brazil

Abstract
The most efficient nitrogen management by adjusting the nutrient dose at sowing and top-dressing with the supply period can increase the oat yield with greater sustainability. Considering the main cereal succession systems in Brazil and independent of the agricultural year condition, the objective of the study was to propose combination of nitrogen adjusted dose at sowing and at top-dressing with the most adequate moment of supply over the biomass and oat grain yield. The experiment was conducted in the years 2015, 2016 and 2017, in Augusto Pestana, RS, Brazil. The experimental plot was a randomized block design with four replicates, in a 4 x 4 factorial model, and four nitrogen rates at sowing (0 - control sample, 10, 30 and 60 kg ha-1), changing the top-dressing dose at total of 70 and 100 kg ha-1 in soybean / oat succession system and maize / oats, respectively. Expecting 4000 kg ha-1 of grain yield, with top-dressing supply in four periods (0, 10, 30 and 60 days after the emergency). The nitrogen management in oat, the combination of the adjusted dose at sowing and at top-dressing with the supply season shows the need to combine the technical recommendations of fertilization with the meteorological conditions of cropping. The absence of nitrogen at sowing and total dose applied at top-dressing, 30 to 35 days after emergence, increased the biomass and grains yield, regardless of condition of the agricultural year and succession system.

Pages 23-31 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2333
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Dual crop coefficients and performance of evapotranspiration methods in irrigated wheat

Tonny José Araújo da Silva, William Fenner, Edna Maria Bonfim-Silva, Thiago Franco Duarte, Thiago Henrique Ferreira Matos Castañon, Luana Glaup Araújo Dourado, Maria Débora Loiola Bezerra

Federal University of Mato Grosso - UFMT, Institute of Agricultural and Technological Sciences - ICAT, 5055 Students Avenue Rondonópolis, 78.735-901, Brazil
Federal University of Mato Grosso - UFMT, Faculty of Agronomy and Zootechnic - FAAZ, 2367, Fernando Corrêa da Costa Avenue, 78060-900, Cuiabá, Brazil

Abstract
Water availability, fertilizer management and crop rotation are fundamental to the sustainability of agriculture and food security. Thus, the objective of this study was the determination of crops coefficients, verification and comparison of methods of estimation and determination of the evapotranspiration of irrigated wheat. The experiment was carried out during two consecutive years, in which BRS 254 varieties were cultivated in 2016 and BRS 394 in the year 2017. The evapotranspiration was estimated and determined using the dual kc methodology, FAO-56, with plants grown in 12 lysimeters filled with soil monoliths, and the loss of water by evaporation measured by weighing small-lysimeters. Evapotranspiration was also determined by the water balance method. The results measured in the lysimeters (standard method) were compared with the data simulated by the dual kc method and determined by method of soil water balance, in order to determine the accuracy and efficiency of the methods used. The coefficients used to determine the efficiency of the methods were the RMSE, the RSR and the confidence index "c". The total evapotranspiration of the crop in both years of cultivation was 360 mm, with mean values of 3.87 mm d-1 for cultivar BRS 254 and 4.10 mm d-1 for cultivar BRS 394. The basal crops coefficients in the emergence, tillering, flowering, maturation and harvest stages were 0.42, 0.78, 0.94, 0.74 and 0.47 for cultivar BRS 254 and 0.28, 0.27, 0.65, 0.98 and 0.66 for cultivar BRS 394. The soil water evaporation coefficients at the respective stages are 0.72, 0.52, 0.39, 0.58 and 0.13 for cultivar BRS 254 and 1.04, 0.96, 0.65, 0.34 and 0.51 for cultivar BRS 394. Ke represents on average about 47% of the evapotranspiration of the irrigated wheat crop. Between methods tested, lysimeter is the best to wheat transpiration followed by FAO method and soil water balance. The use of any methods should consider the objectives and resources availability.

Pages 32-40 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.21.15.01.2365
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Influence of periods of coexistence of weeds on organic okra production

Raimundo Nonato Viana Santos, Luciana Lins Oliveira Santos, Luiz Junior Pereira Marques, Antônia Alice Costa Rodrigues, Maria José Pinheiro Correa, Mário Luiz Ribeiro Mesquita*, Maria Rosângela Malheiros Silva

Universidade Estadual do Maranhão, Centro de Ciências Agrárias, Programa de Pós-Graduação em Agroecologia, São Luís, MA, Brasil
Instituto Federal de Educação, Ciência e Tecnologia do Maranhão, Campus Maracanã, São Luís, MA, Brasil
Departamento de Química e Biologia, Universidade Estadual do Maranhão, São Luís, MA, Brasil
Universidade Estadual do Maranhão, Programa de Pós-Graduação em Agricultura e Ambiente, São Luís, MA, Brasil

Abstract
Weed management in okra grown in organic system minimizes crop yield losses. Thus, the objective of this study was to determine the period prior to weed interference in okra grown in organic system during the rainy and dry seasons in the state of Maranhão, northeastern Brazil. Experiments were conducted in the rainy and dry seasons in randomized block design with seven treatments and four replications. The treatments were T1 = weeds coexistence with okra for 7 days; T2 = coexistence for 14 days; T3 = coexistence for 21 days; T4 = coexistence for 28 days; T5 = coexistence for 35 days; T6 = coexistence for 42 days and, T7 = coexistence for 74 days). In addition to these treatments, we kept a control treatment with weed free until harvest to obtain maximum yield. At the end of each period of weed coexistence with the crop, three weed samples were collected in 0.25 m² to evaluate density, dry mass and to analise phytosociological parameters. The main weeds in both seasons were Commelina benghalensis, Cynodon dactylon, Eleusine indica, Alternanthera tenella and Amaranthus spinosus. The coexistence of weeds with the crop until harvest caused losses of 51% in the rainy season and 67% in the dry season compared to weed free control. In the rainy season, the period before weed interference (PBI) on okra crop of organic system was 12 days after emergence (DAE). In the dry season, 5% yield loss was observed 4 days after transplanting (DAT). Weed management in organic okra should be crried out earlier in the dry season than in the rainy season to avoid high yield losses.

Pages 41-47 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2383
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Selection of soybean genotypes for yield, size, and oil and protein contents

Everton Luis Finoto, Maria Beatriz Bernardes Soares, José de Anchieta Alves de Albuquerque, João Luiz Lopes Monteiro Neto, Sonicley da Silva Maia2, Sérgio Doná, Edvan Alves Chagas, Edgley Soares-da-Silva, Carlos Abanto-Rodríguez

Paulista Agency Agribusiness Technology, North Center Pole, Pindorama, SP, Brazil
Federal University of Roraima (UFRR), Boa Vista, RR, Brazil
Roraimense College of Higher Education, Boa Vista, RR, Brazil
Paulista Agency Agribusiness Technology, Middle Pole, Paranapanema, SP, Brazil
Brazilian Agricultural Research Corporation (EMBRAPA), Boa Vista, RR, Brazil
Research Institute of the Peruvian Amazon (IIAP), Ucayali, Peru

Abstract
A set of experiments was developed involving a randomized block design with three replications to evaluate 17 soybean genotypes for yield, size, and oil and protein contents. Soybean genotypes Conquista, CD 223 AP, Elite, Garantia, Bioagro, M-Soy 8400, M-soy 8001, Nambu, Sambaíba, Esplendor, UFVS 2006, UFVS 2005, UFVTN 102, UVF 18, UFV 16, Valiosa RR, and Vencedora were tested. The genotypes were compared and correlated with the following variables: plant height (PH), first pod height (FPH), yield, and oil and protein contents. The genotypes with the highest PH and FPH were Sambaíba, UFV 18, and Garantia, which, together with M-Soy 8001, also had the highest grain oil contents of 20.93, 21.16, 21.02, and 21.95, respectively. Genotype Bioagro had the highest grain protein content, and the genotypes Elite and Nambu were the most productive. Oil content had a negative correlation with protein content, and yield had a positive correlation with plant size in the evaluated soybean genotypes.
Soybean (Glycine max (L.) Merrill) is one of the main oilseeds produced in the world, and is being used in the production of oils, cosmetics, and human and animal feed, making the plant highly important for the economic development of producing and consuming countries. In Brazil, soybean development has occurred effectively through genetic breeding programs, which have increased yield through the selection of genotypes adapted to the edaphoclimatic conditions of each region (Vasconcelos et al., 2015; Finoto et al., 2017).

Pages 48-50 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2390
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Influence of the mass of Luetzelburgia auriculata (Allemão) Ducke seeds on tolerance to saline stress

Maria de Fátima de Queiroz Lopes*, Riselane de Lucena Alcântara Bruno, Ronimeire Torres da Silva, Francisco Hélio Alves de Andrade, Lucas Kennedy Silva Lima, Leonardo Vieira de Sousa, William Santana Alves

Universidade Federal da Paraíba UFPB, Brazil
Universidade Federal de Lavras UFLA, Brazil
Universidade Federal do Recôncavo da Bahia UFRB, Brazil

Abstract
Luetzelburgia auriculata is used in the reforestation of degraded areas in Brazil due to its adaptation to the conditions of the country’s semiarid region. However, saline stress is one of the main abiotic factors with a negative impact on plant development. The aim of the present study was to evaluate the influence of the mass of Luetzelburguia auriculata seeds on tolerance to saline stress. The experiment was conducted with a completely randomized design in a 2 x 5 factorial scheme with two classes of seeds [light (< 0.35 g) and heavy (≥ 0.35 g)], from ten morphologically similar mother plants that showed natural variation in seed mass, and five salinity levels, distributed in four replicates of 25 seeds. We evaluated the following variables: germination rate; germination speed index; mean germination time; initial seedling growth; and fresh and dry mass of the shoots, cotyledons and roots. The data were submitted to analysis of variance. Means for seed classes were compared using the F-test and regression analysis was performed for NaCl levels. The increase in saline stress led to reductions in germination, root length, fresh and dry mass of the shoots, and the GSI, as well as a delay in MGT. Seedlings from heavy seeds (≥ 0.35 g) exhibited greater tolerance to salt stress than those from light seeds (< 0.35 g), due to lower occlusion caused by NaCl levels. Thus, heavy seeds of L. auriculata are more tolerant to salt stress and should be prioritized, especially in the presence of high salinity levels.

Pages 51-57 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2487
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Economic feasibility of potato production influenced by intra-row plant spacing under mango-based agroforestry system

Md. Hafiz All Amin, Babul Kumar Das, Most. Mottakina Akter, Panu Thainiramit, Warangkana Jutidamrongphan, Kua-anan Techato*, Tachaya Sangkakool

Agroforestry and Environment, Faculty of Agriculture, Hajee Mohammad Danesh Science and Technology University, Dinajpur-5200, Bangladesh
Sustainable Energy Management, Faculty of Environmental Management, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
Agriculture Innovation and Management Division, Faculty of Natural Resources, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
Environmental Assessment and Technology for Hazardous Waste Management Research Center, Faculty of Environmental Management, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand
Rajamangala University of Technology Srivijaya, Faculty of Architecture; Hatyai, Songkhla 90112 Thailand

Abstract
For ensuring the food security and maximum use of land, the potato production under a mango-based agroforestry system is an effective production approach. The purpose of this study was to assess the yield potential and the economic benefits of potato production under a mango-based agroforestry system. The potato tubers were planted in a 10-year-old mango orchard and open field condition. The experiment was laid out following a split plot design with three (3) replications. Potato production system under mango orchard and open field were arranged in main plots T0 = potato sole cropping (control) and T1 = potato under mango-based agroforestry system. On the other hand, potato intra-row plant spacing were in sub-plots S0 = 60 × 20 cm2, S1 = 60 × 25 cm2 and S2 = 60 × 30 cm2. The data of yield characters of potatoes were investigated. The cost of production, gross & net return and benefit-cost ratio was calculated for economic analysis. The results show that the closest (60 x 20 cm2) intra-row plant spacing produced the highest yield while the economic returns from potatoes grown under the mango-based agroforestry system were higher than those derived from cropped grown as a sole crop or potatoes cultivation alone (gross returns US$3508/ha, net returns US$1642/ha). Further, the benefit-cost ratio from the combined cultivation of potatoes and mangos was 2.14 which was 20 % higher than growing potatoes as a sole crop. Thus, the cultivation of potatoes under a mango-based agroforestry system offers a significant financial benefit to farmers while ensuring the sustainable use of vacant space in mango orchards.

Pages 58-66 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2602
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Chemical changes in soil with use of pelletized organomineral fertilizer made from biosolids and sugarcane filter cake

João George Moreira, Julio Cesar Delvaux*, Mara Lúcia Martins Magela, Vanderley José Pereira, Reginaldo de Carmargo, and Regina Maria Quintão Lana

Institute of Agrarian Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
Federal Institute of Education, Science and Technology of Triângulo Mineiro, Ituiutaba Campus, Ituiutaba, Minas Gerais, Brazil

Abstract
Soil fertility has become an interconnected aspect of modern agriculture, incorporating factors such as nutrient availability from soil, and its revision has become necessary for ensuring sustainability. Therefore, to understand the solubility of nutrients from organomineral fertilizers pelleted with biosolids and sugarcane filter cake, and to evaluate the resulting chemical changes in soil from its use, an experiment was performed in a completely randomized design. The experiment was done with four replicates in a 3 × 5 +1 factorial scheme, using three fertilizer sources (mineral fertilizer, organomineral fertilizer pelletized with biosolids, and organomineral fertilizer pelletized with the filter cake); five doses (60%, 80%, 100%, 120%, and 140% of the recommended dose of fertilization for corn); and an additional control treatment (absence of fertilization). The formulation of the organomineral fertilizers was 5-17-10 with 10% total organic carbon. All fertilizer sources were packed in a microfiber cloth positioned 1 cm below the surface of the soil and incubated for 60 days. Subsequent evaluation of chemical attributes: pH H2O (1:2.5); pH SMP (Shoemaker-McLean-Pratt); and the content of exchangeable aluminum, phosphorus, potassium, calcium, magnesium, silica, and organic matter within the soil was done. Organomineral fertilizers pelleted with biosolids or filter cake do not acidify the soil, but they were found to reduce aluminum saturation and promote a slow release of nutrients, which allowed a more balanced base in the soil. This then ensured a better balance of nutrients, with greater cation exchange capacity, base sums, and base saturation. The use of these fertilizers can contribute to stabilizing the pH of the soil with fewer applications of acidity correctives.

Pages 67-72 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2645
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Salinity levels in growth and production of curly lettuce (Elba, Cristina and Veneranda) grown in hydroponic system

Josilda França Xavier*, Carlos Alberto Vieira de Azevedo, Julio Cesar Rodrigues de Sales, Marcia Rejane de Queiroz Almeida Azevedo, Josely Fernandes Dantas, Vera Lúcia Antunes de Lima, Josivanda Palmeira Gomes, Antônio Fernandes Monteiro Filho

Federal University of Campina Grande, Academic Unit of Agricultural Engineering, Campina Grande, 58429-140, Paraíba, Brazil
Productivity CNPq Fellowof Reseach, 1B level, Brazil
State University of Paraíba, Center of Environmental and Agrarian Sciences, Lagoa Seca, 58117-000, Paraíba, Brazil

Abstract
The objective of this research was to evaluate the different salinity levels on growth and production of three cultivars (Elba, Cristina and Veneranda) of curly lettuce in a hydroponic system using the Nutrient film technique (NFT). The design was randomized blocks in a split plot scheme, in which treatments constituted of nutrition solutions: S1 = Furlani (1.9 dS m-1) and six solutions prepared from Furlani solution in order to present the electrical conductivities of (S2 = 2.4; S3 = 2.9; S4 = 3.4; S5 = 3.9; S6 = 4.4 and S7 = 4.9 dS m-1) with three repetitions. The electrical conductivities were obtained by addition of NaCl. The subplots corresponded to the cultivars Elba, Cristina and Veneranda. The following variables were evaluated: Number of leaves per plant (NLP); Total production (TP); Commercial production (CP); Stem diameter (SD); Fresh leaf mass (FLM), Dry leaf mass (DLM) and Dry stem mass (DSM). Nutritional solutions (S1 and S2) promoted the best results for all variables studied. The highest number of sheets (NS) were found in cultivars Elba and Veneranda when the solutions were used (S1 and S2). The highest yields for (TP) (PC) and (FLM) were found in the cultivar Veneranda with nutrient solutions (S1 and S2). The highest value for dry leaf mass (DLM) and dry stem mass (DSM) was found in the cultivar Veneranda.

Pages 73-81 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2747

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Nitric oxide as a way to mitigate copper (Cu) toxicity in the emergence and initial growth of maize seedling (Zea mays L.)

Ana Ecidia de Araújo Brito*, Gerson Diego Pamplona de Albuquerque, Juscelino Gonçalves Palheta, Jessica Suellen Silva Teixeira, Diana Jhulia Palheta de Sousa, Keila Beatriz Silva Teixeira, Glauco André dos Santos Nogueira, Cândido Ferreira de Oliveira Neto, Ismael de Jesus Matos Viégas, Ricardo Shigueru Okumura

Agricultural Sciences Institute, Federal Rural University of Amazônia, CEP: 66077-530, Belém, Pará, Brazil
Federal Rural University of Amazônia, Capanema Campus, Tv. Santa Cruz, 470 - Campinho, PA
Federal Rural University of Amazônia, Parauapebas Campus, CEP: 68515-000, endereço: PA-275 s / n Zona Rural, Parauapebas, Pará, Brazil

Abstract
The aim of this study is to assess the effect of sodium nitroprusside-NPS (nitric oxide donor) on the emergence and initial growth of maize seedlings (Zea mays L.) subjected to different copper concentrations. The study followed a completely randomized design at 4 x 3 factorial arrangement, with 12 treatments and 8 repetitions, totally 96 trays with 25 seedlings per repetition. Seedlings were soaked in sodium nitroprusside (SNP) solution (0.75 and 150 µM - donor), sodium ferrocyanide (SF) (0.75 and 150 µM - compensator) and deionized water (control) on Germitest paper for 48 hours. Next, they were placed on sand saturated with CuSO4.5H2O at concentrations of 0, 100 and 200 µM. The results showed that SNP doses were not capable of mitigating copper toxicity in seedling emergence, influencing emergence speed coefficient and prolonging the mean emergence time of plants subjected to copper concentrations of 100 µM and 200 µM. Copper concentrations rose the number of abnormal seedlings and had negative influence on plant biometrics and biomass. Copper concentration of 200 µM increased proline content in the roots. NPS and sodium ferrocyanide application had effect on emergence speed index, shoot and root dry mass and on proline content in the shoot and roots. This outcome highlights that such effects were caused by treatments related to release of cyanide found in sodium nitroprusside (SNP), rather than to nitric oxide (NO).

Pages 82-87 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2805
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Use of P for three potato clones in soil and in soilless cultivation

Darlene Sausen*, Ivan Ricardo Carvalho, Márcio Renan Weber Schorr, Miriam da Silva Tavares, Aline Soares Pereira, Athos Odin Severo Dorneles, Daniele Bernardy, Francine Lautenchleger, Dilson Antônio Bisognin, Fernando Teixeira Nicoloso

Federal University of Santa Maria, Santa Maria, RS, Brazil
Regional University of the Northwest of the State of Rio Grande do Sul, Ijuí, RS, Brazil
National Supply Company, Porto Alegre, RS, Brazil
Goiás State University, Posse, GO, Brazil
University of the Midwest, Guarapuava, PR, Brazil

Abstract
The objective of this work was to verify the nutritional efficiency to phosphorus (P) as well as the responses of the use of P for three potato clones in soil and soilless cultivation (semi hydroponic). For this purpose, the Asterix, SMIC 148-A and SMINIA 793101-3 clones were evaluated under high and low P levels in soil growing (70 and 560kg P2O5 ha-1) and in soilless cultivation using sand as substrate (2.32 and 23.2mg P L-1 of nutritive solution). Rooting efficiency, absorption, translocation and use of P, fresh tuber mass, total dry mass and harvest index were evaluated in the clones. Each clone responds differently to the growing systems used in terms of nutritional efficiency for P. In both growing systems, the Asterix, SMIC 148-A and SMINIA 793101-3 clones did not show any increase in the absorption efficiency and in the efficiency of using P to compensate for the low level of P, which may have caused the reduction in total dry mass under low P. The restriction of P causes a reduction in tuber fresh mass for the Asterix and SMINIA 793101-3 clones in the two growing systems tested and for the SMIC 148-A clone only in soilless cultivation. Asterix is the clone with the highest harvest index under low P in the field, even without differing from the others in soilless cultivation.

Pages 88-92 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2816
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Efficiency of phosphorus use in potato clones in two contrasting growing seasons

Darlene Sausen*, Ivan Ricardo Carvalho, Miriam da Silva Tavares, Márcio Renan Weber Schorr, Ritieli Baptista Mambrin, Jover da Silva Alves, Camila Peligrinotti Tarouco, Alessandro Dal`Col Lucio, Francine Lautenchleger, Fernando Teixeira Nicoloso

Federal University of Santa Maria, Santa Maria, RS, Brazil
Northwest Regional University of the State of Rio Grande Do Sul, Ijuí, RS, Brazil
Goiás State University, Posse, GO, Brazil
National Supply Company, Porto Alegre, RS, Brazil
Riograndense Higher Education Center, Marau, RS, Brazil
University of the Midwest, Guarapuava, PR, Brazil

Abstract
In Rio Grande do Sul the potato (Solanum tuberosum L.) can be grown in fall and spring. However, due to the contrasting weather conditions between these two seasons, which directly influence the growth of plants and the formation of tubers, it is necessary to identify potato clones adapted to such growing conditions. Thus, this work was carried out to characterize the efficiency of P use in potato clones grown in two contrasting seasons, in an off-soil growing system using sand as a substrate. The treatments were combined in a 2 x 4 x 2 factorial, consisting of two levels of P in the nutrient solution (2.32 and 23.2 mg P L-1), four potato clones (Asterix, Atlantic, SMIC 148-A and SMINIA 793101-3) and two growing seasons (spring and fall). The number of leaves and tubers per plant, the fresh and dry mass of the tubers, fresh mass of the shoot, P concentration in shoot and tubers, and efficiency of P use were determined. There is a difference between the potato clones in terms of the efficiency of P use in the spring and autumn crops of Rio Grande do Sul. Asterix and SMINIA 793101-3 clones show higher productivity in the spring growing and without P. restriction. SMIC 148-A clone was not influenced by the growing season, as long as the availability of P is not a limiting factor. Atlantic clone shows good production when grown in the fall, regardless of the level of P used.

Pages 93-97 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2818
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Soil conditioners as candidates to mitigate salt/water stress effects on sorghum growth and soil properties

Mayara Mariana Alves da Silva, Luiz Guilherme Medeiros Pessoa*, Josimar Bento Simplício, Wagner Luís da Silva Souza, Maria Betânia Galvão dos Santos Freire, Eduardo Soares de Souza, Eduardo Silva dos Santos, Márcio Fléquisson Alves Miranda, Caetano Claudio Pereira Júnior

Rural Federal University of Pernambuco, Department of Plant Production, Serra Talhada – PE, Brazil
Federal Institute of Pernambuco, Barreiros – PE, Brazil
Rural Federal University of Pernambuco, Department of Agronomy, Recife – PE, Brazil
Federal University of Maranhão, Center of Agricultural and Environmental Sciences, Chapadinha – MA, Brazil
Federal Institute of Pernambuco, Vitória de Santo Antão – PE, Brazil

Abstract
In arid and semiarid regions the use of saline water is common in agricultural irrigation, due to the scarcity of high-quality irrigation water. Thus, agriculture faces a challenge in developing strategies to grow crops under such adverse conditions in these regions. The objectives of this research are to study soil chemical properties and sorghum growth response to saline irrigation levels and application of soil conditioners. A greenhouse experiment (4x5) was carried out using a Cambisol cultivated with sorghum and irrigated with five saline water levels: 100%, 80%, 60%, 40% and 20% of soil field capacity (FC). Soils were treated with no soil conditioner (control), organic matter, elemental sulfur (S0) + organic matter and gypsum + organic matter, applied to the soils 30 days before sorghum planting. At 60 days after plant emergence, measurements were recorded for: leaf water potential, plant dry weight, soil P availability, and soil chemical properties. Increasing saline water levels reduced exchangeable and soluble cations and saline variables. Organic matter + elemental sulfur promoted the highest levels of P in the soil and soil saturation extract. This mixture and the saline irrigation of 60% of field capacity promoted the greatest plant growth. However the organic matter + gypsum mixture promoted higher leaf water potential in relation to the other conditioners tested. The saline irrigation level equivalent to 60% of field capacity and the incorporation of organic matter + S0 were sufficient to reduce soil salinity and sodicity, maintaining P and soluble/exchangeable cations contents to a level that best promoted sorghum growth.

Pages 98-106 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2881
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Characterizing the photosynthetic ability of the submergence-tolerant rice variety of Inpari30 via maximum quantum yield performance during transient flooding stress and recovery

Arinal Haq Izzawati Nurrahma, Shin Yabuta, Ahmad Junaedi, Jun-Ichi Sakagami*

The United Graduate School in Agriculture Sciences, Kagoshima University, Kagoshima, Japan
Faculty of Agriculture, Kagoshima University, Kagoshima, Japan
Faculty of Agriculture, Bogor Agricultural University, Bogor, Indonesia

Abstract
Submergence is an environmental challenge for crop cultivation which causes physiological perturbation and yield loss. Tolerant genotypes are characterized by the ability to maintain physiological processes, especially photosynthesis, minimizing the negative effects of flooding stress. This experiment was aimed to examine the photosynthetic ability during submergence and a recovery period in rice variety of Inpari30 (carrying gene Sub1) compared to IR72442 (an elongation type) under control and submergence treatment. A randomized complete block design was employed in this experiment with three replications. The first factor was the environmental condition consisting of control and submergence. The second factor was rice varieties consisting of Inpari30 and IR72442. Fourteen-day-old seedlings were submerged under 35 cm of water depth for 6 days and re-aerated by lowering the water level up to the stem base for 6 days of recovery. Measurement of plant height, SPAD, Fv/Fm and photosynthetic rate were taken continuously from the same plant sample following the experimental stage. The results showed that shoot length increased significantly more in IR72442 than in the quiescent Inpari30. The noticeable decline was observed in the photosynthetic rate of both varieties during submergence with chlorophyll content and chlorophyll fluorescence (Fv/Fm) decreased more severely in IR72442 than in Inpari30. After flooding, Inpari30 adapted quickly to the aerobic environment, as shown by a recovery in Fv/Fm and accumulated dry weight more quickly than IR72442. We concluded that the Sub1 genotype of Inpari30 confers the ability to maintain maximum quantum yield of PSII under conditions of limiting gas exchange for photosynthesis for adapting post submergence.

Pages 107-113 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2889
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Emergence and initial growth of Mimosa bimucronata (DC) O. KTZE. seedlings at different depths and position of sowing

Luan Danilo Ferreira de Andrade Melo*, João Luciano de Andrade Melo Junior, Lívia Francyne Gomes Chaves, Dougllas Ferreira da Rocha, Maria Inajal Rodrigues da Silva das Neves, Edilma Pereira Gonçalves, Wesley Oliveira de Assis, Reinaldo de Alencar Paes, Aldair de Souza Medeiros, Ivomberg Dourado Magalhães, Natália Marinho Silva Crisostomo

Department of Agroecology and Agronomy, University Federal of Alagoas – UFAL, Brazil
Department of Agronomy, University Federal of Agreste of Pernambuco, UFAPE, Brazil

Abstract
Mimosa bimucronata (DC) O. KTZE. (maricá), belong to the family Fabaceae is a forest species found in Latin America. This species has been used in landscaping, reforestation and restoration of degraded areas and permanent preservation. The present work aimed to verify the effect of the position of the seed and the depth of sowing in the emergence and initial growth of seedlings of M. bimucronata. The experiment was carried out in a completely randomized design with four replications including 25 seeds per treatment. Different positions of the seeds were used in the sand substrate: downward facing (HB) thread; facing the side, forming an angle of 90 ° to the imaginary axis with the substrate (HL); and upward facing wire (HC), at seeding depths of 1, 2, 3, 4, 5 and 6 cm. The following variables were evaluated: emergence percentage, first count and emergence speed index, seedling length and dry mass. The results showed that HL at a depth of 1 cm sowing produces higher vigor seedlings.

Pages 114-118 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2920
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The potential of nutrient cycling in cover plants in response to phosphate fertilization

Érica de Oliveira Araújo, Vitório Macieski Neto, José Vanor Felini Catânio, Rodrigo Alvarenga da Silva, Nélio Ranieli Ferreira de Paula, Diogo de Souza Freitas, Jiovane Anderson da Silva Ribeiro, Daniele Jesus Venturim

Department of Agriculture, Federal Institute of Education, Science and Technology, Rondonia State, Campus Colorado do Oeste, Brazil
Department of Integration, Teaching, Research and Extension, Federal Institute of Education, Science and Technology, Rondonia State, Campus Colorado do Oeste, Brazil

Abstract
Residues of crops and cover crops contain considerable amounts of phosphorus (P) in their tissues, which through their mineralization can meet much of the requirement of crops. In this context, the present study aimed to evaluate the biomass production, P absorption and use of different cover crops subjected to phosphate fertilization, and its effects on the absorption and use of nitrogen (N), phosphorus (P) and potassium (K). The experiment was conducted in a protected environment from August to December 2019. The experimental design was completely randomized, arranged in a 7 x 3 scheme, consisting of the planting of seven species of cover crops (Crotalaria spectabilis, Crotalaria breviflora, Crotalaria ochroleuca, Mucuna aterrima, Mucuna pruriens, Dolichos lablab and Canavalia ensiformis), three P rates (0, 80 and 160 kg ha-1 of P2O5) and four replicates. At the time of full flowering, the cover species were cut and divided into root and shoot for subsequent determination of dry mass production, nutrient content and absorption efficiency and nutrient utilization. The results showed that Canavalia ensiformis promoted higher yield of shoot fresh and dry mass, P content in the shoots and higher N and P absorption efficiency. N and P contents in Dolichos lablab roots were higher at the highest P rates (160 kg ha-1 of P), without close relationship with the supply of shoot dry mass. The P dose of 160 kg ha-1 had an increasing and significant effect on the production of shoot fresh mass and dry mass, N, P and K contents in the shoots, N, P and K contents in the roots and efficiency of N, P and K use by the different cover crops. The P rates of 80 kg ha-1 increased the N, P and K contents in the shoots of Crotalaria ochroleuca, Crotalaria breviflora and Crotalaria spectabilis; and at higher P rates, there was a reduction in nutrient accumulation. The species Mucuna pruriens and Mucuna aterrima were efficient in the use of N, P and K at P rates of 160 kg ha-1.

Pages 119-128 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2923
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Dynamics of formation and functioning of legume-rhizobial symbiosis Mesorhizobium ciceri-Cicer arietinum (variety Pam'iat')

Olha Lohosha, Yuliia Vorobei

Institute of Agricultural Microbiology and Agroindustrial Manufacture of the National Academy of Agricultural Sciences of Ukraine, Shevchenka 97, 14027 Chernihiv, Ukraine

Abstract
The study of the dynamics of formation and functioning of symbiosis between nodule bacteria and chickpea plants was carried out in the northern region of Ukraine in the experimental plots, where the local population of chickpea mesorhizobia began to form. A new strain of Mesorhizobium ciceri ND-64 and a reference Mesorhizobium ciceri H-12 were used to inoculate Cicer arietinum seeds. The field study determined the number, weight, nitrogenase activity of nodules on the chickpea roots, dry green mass and mass of roots of chickpea plants of Pam'iat' variety. Samplings were carried out nine times in different phases of plant vegetation, starting from the branching phase and ending with the phase of complete maturity of seeds. The study showed that round and oval nodules appeared on the roots of chickpea plants during the branching stage. Gradually, they increased in size and in the phase of budding formed splices. The largest number of nodules (43.1 units/plant) was formed in the bean formation phase. The highest nitrogenase activity of the nodules was registered in the flowering phase. It was found that the bacterization of M. ciceri ND-64 promotes earlier formation and long-term functioning of the symbiotic apparatus in comparison with the reference strain and the control variant. The highest symbiotic rates under inoculation with M. ciceri ND-64 were registered at the beginning of the bean formation phase. In the control variant and with inoculation of M. ciceri H-12, these parameters were the highest later (at the end of the bean formation phase) and rapidly decreased in the subsequent phases, while the nodules formed by M. ciceri ND-64 continued to functioning actively. The positive effect of inoculation of chickpea seeds with a suspension of M. ciceri ND-64 on the increase in the number of beans and seeds per plant, weight of 1000 seeds and yield of chickpea plants was shown. Considering the obtained data, the new strain M. ciceri ND-64 is a promising bioagent of a microbial preparation for bacterization of chickpea.

Pages 129-136 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2952
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Cover crops and multifunctional microorganisms can affect development of upland rice

Fernando Couto de Araujo*, Adriano Stephan Nascente, Marta Cristina Corsi de Filippi, Mariana Aguiar Silva, Vinícius Silva Sousa, Anna Cristina Lanna

Agronomy School, Goiás Federal University, Goiânia, State of Goiás, 74.690-900, Brazil
Brazilian Agricultural Research Corporation (EMBRAPA), Rice and Beans Research Center, P.O. Box 179, Highway 462, km 12, Santo Antônio de Goiás, State of Goiás, 75.375-000, Brazil

Abstract
Cultivation of cover crops in the off-season and the use of multifunctional microorganisms are strategic technologies to ensure sustainability in upland rice production. The objective of this work was to determine the effect of mix of cover crops cultivated in the off-season and multifunctional microorganisms on the growth promotion of upland rice plants, under no-tillage systems conducted in the Brazilian Cerrado. The experimental design was a complete randomized blocks in a 6x2 factorial scheme with four replications. The treatments consisted of a combination of six soil covering plants 1. Fallow (control); 2. millet (Pennisetum glaucum) and crotalaria (Crotalaria juncea, C. spectabilis and C. ochroleuca); 3. millet and pigeon pea (Cajanus cajanus); 4. millet and Urochoa ruziziensis; 5. millet, U. ruziziensis and pigeon pea; and 6. millet and buckwheat (Fagopyrum esculentum)), with or without the application of coinoculants 1301 (Bacillus sp.) + Azospirillum sp. The mix of cover crops millet + U. ruziziensis and millet + U. ruziziensis + pigeon pea recorded the largest biomass production and the highest nutrient content in the straw. Rice plants cultivated after millet + pigeon pea showed largest transpiration and stomata conductance. The application of multifunctional microorganisms contributed to an increase of 29% in the photosynthetic rates of rice plants. The highest upland rice grain yield was achieved after mix of millet + crotalaria (Crotalaria juncea, C. spectabilis and C. ochroleuca). The application of multifunctional microorganisms increased the mass of 1000 grains, but does not affect rice grain yield. Our results showed that cover crops significantly affected rice grain yield and the multifunctional microorganisms affected grain quality.

Pages 137-144 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2963
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Absorption of nutrients and chemical reconditioning of red latosol by cover plants cultivated in Amazon environment

Érica de Oliveira Araújo, Jiovane Anderson da Silva Ribeiro, Daniele Jesus Venturim, José Vanor Felini Catânio, Vitório Macieski Neto, Diogo de Souza Freitas, Aline Ottes Moreira, Nélio Ranieli Ferreira de Paula, José Henrique de Souza Costa, Willian Junior Silva Costa, Klariston Rodrigues dos Santos

Agronomy, Department of Agriculture, Federal Institute of Education, Science and Technology, Rondonia State, Campus Colorado do Oeste, Brazil
Agronomic Engineering, Department of Agronomy, Federal Institute of Education, Science and Technology, Rondonia State, Campus Colorado do Oeste, Brazil
Animal Production, Department of Integration, Teaching, Research and Extension, Federal Institute of Education, Science and Technology, Rondonia State, Campus Colorado do Oeste, Brazil.
Agriculture, Department of Agriculture, Federal Institute of Education, Science and Technology, Rondonia State, Campus Colorado do Oeste, Brazil

Abstract
Maintaining the balance of the system using cover crops is a promising alternative for the Amazon region. In this context, the present study aimed to evaluate the absorption of nutrients by cover crops and the reconditioning of soil chemical attributes after management with different cover crops. The experiment was conducted in the experimental area of the Federal Institute of Education, Science and Technology of Rondonia, Colorado do Oeste Campus, in the municipality of Colorado do Oeste, RO, Brazil. The experimental design used was completely randomized, arranged in a 7x4 factorial scheme, consisting of seven species of cover crops (Crotalaria spectabilis, Crotalaria breviflora, Crotalaria ochroleuca, Mucuna aterrima, Mucuna pruriens, Dolichos lablab and Canavalia ensiformis) and four sampling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm), with four replicates. The results concluded that the cultivation of Crotalaria spectabilis, Crotalaria ochroleuca and Crotalaria breviflora provided higher dry matter yield. The species Dolichos lablab stood out in the accumulation of nitrogen, phosphorus, calcium and sulfur in the leaves at full flowering. The contents of organic matter, total carbon, C/N ratio, N-total, P, K, Ca2+ and Mg2+ of the soil were higher at the depth of 0-10 cm with a decrease in subsurface layers. The species Dolichos lablab and Mucuna pruriens are efficient in terms of supplying organic matter, organic carbon, C/N ratio, N-total, phosphorus, calcium and Ca/Mg ratio of the soil, promoting a direct impact on the fertility of its surface layers up to 10 cm deep. Cultivation of Crotalaria breviflora and Crotalaria spectabilis caused variation in soil exchangeable bases, being directly correlated with the values of pH, SB and CEC.

Pages 145-155 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2964
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Characterization of vegetation structure in areas of natural occurrence of Hancornia speciosa Gomes

Régilla Martins dos Reis, Ariadne Enes Rocha, Mary Jane Nunes Carvalho, Larissa de Paula Viana da Silva, Francisca Helena Muniz, Georgiana Eurides de Carvalho Marques, Mário Luiz Ribeiro Mesquita*

Programa de Pós-Graduação em Agroecologia, Universidade Estadual do Maranhão, Brasil
Departamento de Fitotecnia e Fitossanidade, Universidade Estadual do Maranhão, Brasil
Programa de Pós-Graduação em Agronomia, Universidade Estadual Paulista “Júlio de Mesquita Filho” Brasil
Departamento de Biologia e Química, Universidade Estadual do Maranhão, Brasil
Departamento de Química, Instituto Federal de Ciência e Tecnologia-IFMA, São Luís, Brasil
Programa de Pós-Graduação em Agricultura e Ambiente, Universidade Estadual do Maranhão, Brasil

Abstract
The mangabeira (Hancornia speciosa Gomes) has great food and pharmaceutical values but its production is almost entirely made by people gathering fruits in forests, which increases the risk extinction, particularly in savannah regions. Thus, the objective of this study was to compare floristic, phytosociology and species diversity in five areas of natural occurrence of mangabeira. All plants with a diameter at soil level equal to or greater than five cm were selected by the quadrant method in five villages in the state of Maranhão, northeastern Brazil. The assessed variables for the whole vegetation were number of individuals, number of species, total density, the Shannon Diversity Index (H'), the Jaccard Similarity Index, total plant height and diameter at soil level. The phytosociological parameters computed for the mangabeira population were absolute and relative density, frequency and dominance; basal area, importance value and cover value. We recorded 1,696 plants from 26 species and 16 families. Anacardiaceae, Apocynaceae and Fabaceae were the families that stood out most with two species each. The species diversity was low in all villages, varying from H’= 0.659 in Santana to H’ = 1.777 in Recanto. The floristic similarity among the vegetation in all villages was low except between Patizal and Recurso (0.571). For the mangabeira population, the importance value and cover value were higher in Santana, with 79.35% and 85.28% respectively and the highest values of plant height (6.02 meters) and diameter at soil level (13.76 cm) were found in Patizal village. These results could be used for management, preservation and sustainability of the mangabeira in northeastern Brazil.

Pages 156-163 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2017
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Effect of post-emergence applications of imazapyr and imazapic on the growth and grain yield of AHAS-transgene soybean plants

Vinicius Gabriel Caneppele Pereira*, Leandro Paiola Albrecht, Alfredo Junior Paiola Albrecht, Fabio dos Santos Biazoto, Rogério Kosinski, Aderlan Ademir Bottcher, Mateus Dalpubel Mattiuzzi, and Fábio Henrique Krenchinski

São Paulo State University (UNESP) – School of Agricultural Sciences, Botucatu, São Paulo, Brazil
Federal University of Paraná (UFPR) – Department of Agricultural Sciences, Palotina, Paraná, Brazil
State University of Maringá (UEM) – Program of Agricultural Science, Maringá, Paraná, Brazil

Abstract
One of the factors that limit grain yield in soybean crops is weed competition. The objective of the present work was to evaluate the agronomic performance of an AHAS-transgene soybean cultivar (BRS 397; Cultivance®) subjected to different rates of Soyvance® (525 g kg-1 imazapyr, and 175 g kg-1 imazapic). Two field experiments were conducted in the 2015-2016 crop season in two sites with different soil and weather characteristics located in the state of Paraná, Brazil. A completely randomized block design was used, with 11 treatments consisted of different rates of Soyvance®. Phytotoxicity, chlorophyll index, first pod height, plant height, number of pods per plant, 100-seed weight, and grain yield were evaluated. The use of high rates of the herbicide decreased the final height and grain yield of soybean plants in approximately 25% in both locations, but did not affect their 100-seed weight and chlorophyll index. The use of rates of the commercial product higher than that recommended by the manufacturer (100 g ha-1) may affect the agronomic performance of AHAS-transgene soybean plants.

Pages 164-171 | Full Text PDF| doi: 10.21475/ajcs.21.15.01.2182