Volatilization of ammonia in tropical soil with different moisture after application of polymer-coated urea
Mário Miyazawa, Luciano Grillo Gil*, Antonio Costa, Roberto dos Anjos Reis Júnior, Íris Tiski
Soil area, Agronomic Institute of Paraná (IAPAR), Londrina, State of Paraná, CEP 86.047-902, Brazil
Wirstchat, Londrina, State of Paraná, Brazil
Abstract
Nitrogen fertilizer has a significant participation in the cost of agricultural production. It is less efficient agronomically and requires more studies to find strategies to be absorbed by crop. Polymer-coated urea is an alternative for the production of increased efficiency fertilizers. Validation of this technology should be performed for safe adoption in agriculture. The objectives of this work were to evaluate the nitrogen losses by volatilization of ammonia and the nitrogen contents in the nitric (N-NO3-) and ammoniacal (N-NH4+) forms in the tropical soil after application of urea sources. Three greenhouse experiments with different soil moisture conditions were carried out after application of urea, urea treated with NBPT and urea coated with Policote polymer as treatments. Then volatilization of ammonia, N-NO3- and N-NH4+ contents in the soil was evaluated. The volatilization of ammonia was observed after using Policote-coated urea, which was similar to urea treated with NBPT. However, both of which were lower than that observed under urea application. In dry or very humid soil, the ammonia volatilization rate was low. The reduction of the volatilization of ammonia in the soil with Policote-coated urea was related on the humidity, whereas more effective when the conditions were more propitious to the volatilization of ammonia. The Policote-coated urea increased the content of N-NH4+ in the tropical soil compared to urea. The content of N-NH4+ in the soil was higher than N-NO3- after application of fertilizers due to the low organic matter content.
Pages 712-717 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p1820
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Expression of antioxidant genes and photosynthetic apparatus in the soybean crop in competition with Italian ryegrass biotypes (Lolium multiflorum Lam.)
Daiane de Pinho Benemann, Joanei Cechin*, Dirceu Agostinetto, Leandro Vargas
Department of Crop Protection, Federal University of Pelotas, PO Box 354, Capão do Leão -RS, Brazil, Zip Code 96010-900
Researcher of Embrapa Wheat, Department of Weed Science, BR 285 Km 174, PO Box 451, Passo Fundo-RS, Brazil, Zip Code 99001-970
Abstract
Crop-weed competition induces stress in plants causing physiological changes which can be evaluated using the RT-qPCR technique. The aim of this study was to evaluate the stability of candidate reference genes and measure the relative gene expression of antioxidant enzymes and components of the photosynthetic apparatus in soybean in competition with glyphosate-susceptible and resistant Italian ryegrass (Lolium multiflorum Lam.). The experiment was carried out in a greenhouse using replacement series between soybean and Italian ryegrass biotypes. In this study, candidate reference genes were evaluated for use as controls in RT-qPCR to quantify gene expression. An evaluation was made of genes that encode catalase, ascorbate peroxidase, superoxide dismutase, chlorophyll a/b, phytochrome A and cytochrome P450 at 50 days after emergence of the soybean. The SKIP and GAPDH genes were the most stable for soybean and Italian ryegrass, respectively. The soybean subjected to the interspecific competition with the glyphosate-resistant Italian ryegrass biotype showed an increase in superoxide dismutase gene expression. The catalase and cytochrome P450 genes were up-regulated in the susceptible biotype while the other genes were down-regulated. However, the soybean crop under interspecific competition with glyphosate-resistant biotye showed as up-regulated for all the genes evaluated. For the photosynthetic apparatus, cytochrome P450 gene was up-regulated under intraspecific competition on both Italian ryegrass biotypes, while the phytochrome A was up-regulated only in the resistant biotype. Thus, the increase in genes investigated represents a potential tool for the genetic improvement of plants to enhance their competitive capacity.
Pages 718-728 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2008
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Molecular polymorphism in SSR loci of the RB92579 variety: perspectives for use in sugarcane improvement and industrial sector
Rodrigo Desordi, Claudete Aparecida Mangolin, Gustavo Barizon Maranho, Rone Charles Maranho, Maria de Fátima Pires da Silva Machado*
Genetics and Breeding, State University of Maringá, 87020-900 Maringá, PR, Brazil
Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, 87020-900 Maringá, PR, Brazil
Agronomy, State University of Maringá, 87020-900 Maringá, PR, Brazil
Abstract
The sugarcane variety RB92579 has excellent agricultural productivity, very low flowering, efficient water use, and a high content of sucrose. Despite its excellent agricultural productivity, the RB92579 has not been used as a direct parent in sugarcane improvement. The main goal of the present study was to investigate polymorphisms at the SSR and EST-SSR loci of the RB92579 sugarcane variety to evaluate its potential for breeding and generating new varieties and to guide better use by the industrial sector. A total of 92 samples of the RB92679 variety were collected from plants in the fourth cutting stage grown in two Brazilian states: Paraná (PR; South region) and Mato Grosso do Sul (MS; South-Central region). Four primers for DNA simple sequence repeats (SSRs) and eight primers for expressed sequence tags for simple sequence repeats (EST-SSR) were used for DNA amplification. The polymorphism occurrence in the 12 SSR loci was 28% in the PR and MS populations, with a total of 25 alleles and an average of 2.08 alleles/loci. High values for mean observed heterozygosity, a high value for genetic identity and a low level of population differentiation was found in samples from the PR and MS states. The number of polymorphisms in the EST-SSR and noncoding SSR loci as well as the genetic divergence was low. However, the high heterozygosity in both populations indicates that the RB92579 variety can be used as a parent to generate new cultivars. On the other hand, the low coefficient of genetic divergence and high identity coefficient indicate that there is genetic uniformity; therefore, there is no need for differential industrial adaptations for pretreatment or enzymatic hydrolysis of the sugarcane bagasse from RB92579 at the same cutting stage and planted in the two regions (PR and MS).
Pages 729-738 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2010
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The physiological quality of ‘Chilli pepper’ seeds, extracted from fruits harvested at different stages of maturation, with and without post-harvest rest
Pâmela Gomes Nakada-Freitas*, Natália de Brito Lima Lanna, Priscilla Nátaly de Lima Silva, Estefânia Martins Bardiviesso, Ana Emília Barbosa Tavares, Marina Toledo Rodrigues Claudio, Antonio Ismael Inácio Cardoso, Felipe Oliveira Magro, Humberto Sampaio Araújo
São Paulo State University (Unesp), College of Agricultural and Tecnological Sciences, Dracena, SP, Brazil
School of Agronomy and Forest Engineering (FAEF), Garça, SP, Brazil
São Paulo State University (Unesp), School of Agriculture, Botucatu, SP, Brazil
Colleges Integrated Aparício Carvalho- FIMCA, Porto Velho, RO, Brazil
Sakata Seeds Sudamérica, Bragança Paulista, SP, Brazil
Secretariat of Agriculture, Supply and Tourism of Jundiaí, Jundiaí, SP, Brazil
Regional Pole of Technological Development of Agribusiness Extreme West, Andradina, SP, Brazil
Abstract
The objective of this study was to evaluate the physiological quality of ‘Chilli pepper’ seeds, extracted from fruits harvested at different stages of maturation, with and without post-harvest rest. Twelve treatments resulted from the 6 x 2 factorial, with six maturation stages (100% green fruits, 90% green and 10% orange fruits, 10% green and 90% orange fruits, 100% orange fruits, 100% red fruits and 100 % matte red fruits, corresponding to 44, 53, 60, 63, 70 and 73 days after anthesis (DAA), respectively), and fruits with and without rest for seven days. Seeds were evaluated two months after extraction as well as after 14 months of storage in a dry chamber (40% relative humidity and 20°C). The characteristics evaluated were: weight of a thousand seeds, germination, first count, electrical conductivity, emergency test and shoot length of seedlings. Fruits of orange chilli pepper 'Malagueta' kept at rest for seven days and bright red fruits and matte without rest produce seeds with physiological quality, which are maintained after a period of 14 months stored in a chamber with 40% relative humidity at 20°C.
Pages 739-743 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2069
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Application of phosphate fertilization on banana hybrid ‘FHIA 18’and its impact on production performance
Ana Carolina Batista Bolfarini, Fernando Ferrari Putti, Jackson Mirellys Azevedo Souza, Marcelo de Souza Silva, Rafael Bibiano Ferreira, Magali Leonel, Marco Antonio Tecchio, Sarita Leonel*
Department of Horticulture, São Paulo State University (UNESP), School of Agriculture, Botucatu, São Paulo, Brazil
São Paulo State University (UNESP), School of Sciences and Engineering, Tupã, São Paulo, Brazil
São Paulo State University (UNESP), Tropical Root and Starches Center, Botucatu, São Paulo, Brazil
Abstract
FHIA 18 is a hybrid banana that could replace cultivar Prata, which is highly affected by Black Sigatoka and Panama disease. Still, there is a paucity of literature on FHIA 18 nutrient requirements, especially phosphorus. Nevertheless, we aimed to estimate the best phosphorus levels and its effect on the productive characteristics of FHIA 18 during three crop cycles in the city of São Manuel, state of São Paulo. Triple superphosphate has been given at recommended rates of 0, 20, 30, 40, 50 and 60 kg P2O5 ha-1 year-1 for three crop cycles that occurred in January 2014 (first cycle), August 2014 (second cycle) and June 2015 (third cycle). Results indicated that maximum fruit number per bunch was achieved at 30 and 26 kg P2O5 ha-1, corresponding to second and third cycle, respectively. Moreover, there was an increase in bunch mass, fruit mass, number of hands per bunch, mass and length of the fruit in the second hand, when P2O5 reached its maximum values from 20 to 34 kg P2O5 ha-1 year-1, but fruits diameter decreased. Results also showed that FHIA 18 required lower level of P2O5 to achieve maximum yield than the recommended doses for other banana cultivars in the state of São Paulo. Therefore, this current study recommends a rate of 22 kg P2O5 ha-1 year-1 for FHIA 18 to reach its maximum production.
Pages 744-750 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2081
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Microclimate changes, photomorphogenesis and water consumption of Moringa oleifera cuttings under different light spectrums and exogenous phytohormone concentrations
Alexandre Eugênio da Silva, Rener Luciano de Souza Ferraz*, João Paulo da Silva, Patrícia da Silva Costa, Pedro Roberto Almeida Viégas, José Félix de Brito Neto, Alberto Soares de Melo, Kaline de Souza Meira, Cláudio Silva Soares, Ivomberg Dourado Magalhães, Aldair de Souza Medeiros
State University of Paraíba, Center for Agrarian and Environmental Sciences, Lagoa Seca, 58117-000, Paraíba, Brazil
Federal University of Campina Grande, Academic Unit of Agricultural Engineering, Campina Grande, 58109-970, Paraíba, Brazil
Federal University of Sergipe, Department of Agronomic Engineering, São Cristóvão, 49100-000, Sergipe, Brazil
State University of Paraíba, Coordination of the Post-Graduate Program in Agricultural Sciences, Campina Grande, 58429-570, Paraíba, Brazil
Federal University of Alagoas, Department of Plant Production, Maceió, 57072-900, Alagoas, Brazil
Fellow of CNPq Research Productivity, level 2, Brazil
Abstract
Moringa oleifera is one of the most important plants in the world due to its multiple uses as well tolerance to abiotic stress. However, it may presents low quality seedlings in protected environment under thermal and luminous stresses. The current study aimed to evaluate environmental microclimate changes; photomorphogenesis and water use of M. oleifera cuttings under light spectral and phytohormones variations, as well as to identify the most important variables to explain those effects. A completely randomized experimental design was used in a 4 x 4 factorial design with four replications. Four luminosity conditions, white (a transparent plastic layer), blue (two layers of blue cellophane paper), red (two layers of red cellophane paper), and extreme red lights (one layer of red cellophane and one of alternating blue cellophane) and four phytohormones concentrations (0, 25, 50, and 100%) were applied. M. oleifera semi-woody cuttings were collected from 7 am to 9 am from the M. oleifera mother plants, grown on a rural property located in the city of Lagoa Seca, Paraíba, Brazil, with the following characteristics: 15 cm in length, 4 to 5 mm in diameter, and 2 or 3 buds. Throughout the experimental period, environments were monitored to determine illuminance, average air temperature, relative humidity, soil average temperature, and evapotranspirated water consumption by cuttings. The numbers of shoots were recorded weekly. The number of surviving roots and shoots were measured 60 days after M. oleifera cuttings planting. Illuminance was reduced in environments under blue, red, and extreme red lights, respectively. The air temperature was reduced under blue light, while red and extreme red lights induced the increase on air temperature and relative humidity, soil temperature, and therefore, water consumption of cuttings. Protected environments when irradiated with blue light and application of phytohormones at concentrations of 25 and 50% enabled the shootings and survival of cuttings, although no root formation was observed after 60 days from planting. All variables were considered important to explain the effects.
Pages 751-760 | Full Trxt PDF| doi: 10.21475/ajcs.20.14.05.p2096
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Correlation analysis of the SPAD readings and yield of sweet potato (Ipomoea batatas L.) under different agrotechnical conditions
Péter Pepó
University of Debrecen, Faculty of Agricultural and Food Sciences and Environmental Management, Institute of Crop Sciences, Hungary
Abstract
We studied the effect of planting method (flat and ridge planting) and row spacing (0.75-1.0 m) on the yield and SPAD readings of sweet potato (Ásotthalmi 12 variety) in a small-plot field experiment in 2017 and 2018. The experiment was set up in lattice design with 4 replications. The SPAD readings of sweet potato were measured four (2017) and three (2018) times during vegetation period (by Konica Minolta 502). A high yield level was reached both in 2017 (23.23-50.69 t ha-1 marketable yield) and 2018 (33.26-47.34 t ha-1) due to the effects of the favourable soil (chernozem), the near-optimal agrotechnical background, irrigation and the warmer-than-average vegetation period. In both years, higher yields were obtained with flat planting and 0.75 m row spacing. The proportion of non-marketable tubers was between 9.97-15.57% in 2017 and 8.65-11.01% in 2018. The SPADmax values were measured in July (39.61-50.31 in 2017) and in August (49.90-55.33 in 2018). Strong correlation observed among SPAD readings, the whole yield and the marketable yield in both years (r = 0.632*, r = -0.664* and r = 0.709**, respectively). Also, a strong correlation was observed between the planting method and the obtained SPAD readings (r = -0.847**, -0.682* in 2017 and r = -0.634*, -0.488 in 2018, respectively), while there was no correlation between row spacing and SPAD readings (r = -0.006NS-0.190NS). Crop year had a strong effect on SPAD readings (r = 0.639**-0.871**).
Pages 761-765 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2124
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Nitrogen recovery from fertilizers and cover crops by maize crop under no-tillage system
Edson Cabral da Silva, Takashi Muraoka, Alefe Viana Souza Bastos*, Vinícius Ide Franzini, Alinne da Silva, Salatiér Buzetti, Karuppan Sakadevan, Frederico Antonio Loureiro Soares, Marconi Batista Teixeira, Paulo César Ocheuze Trivelin, Leandro Coelho de Araújo
Instituto Federal Goiano - Rio Verde, GO, Brasil
Universidade de São Paulo, Centro de Energia Nuclear na Agricultura - Piracicaba, SP, Brasil
Embrapa Cocais - São Luís - MA, Brasil
Universidade Estadual Paulista “Júlio de Mesquita Filho” (FEIS/UNESP) - Ilha Solteira, SP, Brasil
Soil and Water management & Crop Nutrition Subprogram, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, IAEA, Vienna, Austria
Abstract
Crop rotation associated with the use of cover crops promotes the introduction of crop residues to the soil, with direct and indirect effects on the availability of plant nutrients, especially nitrogen (N). The objectives of this study were to estimate the N utilization from 15N-urea and cover crop residues (labelled with 15N) of maize crops grown in succession, and evaluate the effects of the isolated and combined use of cover crops and urea on maize plant height, yield components, and grain yield, grown under a no-tillage system. Field research was conducted in an Oxisol (Rhodic Hapludox), Cerrado (Savannah) phase. The experimental design was a randomized block with 20 treatments and four replications in a 5x4 factorial scheme. The treatments were four cover crops species: sunn hemp (Crotalaria juncea L.), pigeon pea (Cajanus cajan (L.) Millsp), green velvet bean (Mucuna prurens), and millet (Pennisetum glaucum L.) + spontaneous vegetation (fallow in the off-season), combined with four N rates: 0, 30, 90, and 150 kg ha-1, applied at the sowing and topdressing stages. The results showed that legume cover crops provided maize grain yields equivalent to the application of 80-108 kg ha-1 N as urea. The urea N utilization by the maize was at an average of 43.5 % of the applied amount. The results indicate that cover crops, particularly legume cover crops, are an important source of N to non-legume cereals. Legumes used as cover crops can replace nitrogen fertilizers of more than 80 kg ha, which is both environmentally and economically viable for corn production.
Pages 766-774 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2127
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Mobility of flumioxazin herbicide in a Dystrophic Red Yellow Latosol at Brazilian Southern Amazon
Oscar Mitsuo Yamashita*, Rafael Cesar Tieppo, Ricardo Vicentin Carvalho, Marco Antonio Camillo de Carvalho, Rivanildo Dallacort, Walmor Moya Peres, Grace Queiroz David, Hudson de Oliveira Rabelo, Adriano Maltezo da Rocha, Lara Caroline Alves de Oliveira
Postgraduate Program in Amazonian Biodiversity and Agroecosystems. Mato Grosso State University, Alta Floresta, MT, Brazil
Postgraduate Program in Environments and Production Systems. Mato Grosso State University, Tangará da Serra, MT, Brazil
Faculty of Biological and Agrarian Sciences. Mato Grosso State University, Alta Floresta, MT, Brazil
Abstract
Herbicides are chemicals which can contaminate soil and water, if inadvertently used. In the soil, the herbicide may undergo adsorption and leaching or degradation by physical, chemical and biological processes in addition to being absorbed by the weeds and / or cultivation. The aim of this study was to determine the mobility of flumioxazin in Dystrophic Red Yellow Latosol, in the southern Amazon, using sorghum plant as test under different rainfall indexes. We used PVC pipes, which were filled with soil. The experimental design was completely randomized in a 2x2x5 factorial scheme, consisting of herbicide treatments [with or without flumioxazin (50 g i.a. ha-1)], rain (40 or 80 mm) and soil depths (2.5, 5, 10, 15 and 30 cm). After each rainfall simulation, the tubes were removed and sorghum seeds were placed in the depths 2.5, 5, 10, 15 and 30 cm from the top of the columns. It was observed a higher activity of flumioxazin in the initial 2.5 cm. In all depths where herbicide effect was observed, it was also observed the interruption of sorghum growth, being more intense in the simulations of 80 mm of rainfall. The herbicide presented high adsorptive capacity in Dystrophic Red Yellow Latosol, with mobility up to the first 2.5 cm along the profile.
Pages 775-781 | Full Text PDF| 10.21475/ajcs.20.14.05.p2164
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Coating phosphorus fertilizer with renewable natural polymers
Vinícius José Ribeiro*, Edson Marcio Mattiello, Deusanilde de Jesus Silva, Leonardus Vergütz
Department of Soil Science, Universidade Federal de Viçosa, Viçosa, MG, Brazil, 36570-900
Department of Chemical Engineering, Universidade Federal de Viçosa, Viçosa, MG, Brazil, 36570-900
Abstract
Low phosphorus use efficiency (PUE) is one of the major reasons of poor production worldwide. Among the various approaches used to enhance PUE, polymer coated fertilizers are relatively a new concept. Its main advantages are that they dissolve slowly and release nutrients to plants gradually during the growing season. Keeping this in view, a study was performed in the laboratory to evaluate polymers coated monoammonium phosphate (MAP) to enhance PUE. Commercial MAP and MAP coated with biodegradable polymers with Krafit black liquor (BL) and cellulose acetate (CA) in the concentration (0.5, 1.0, 2.0 wt % coating). The effectiveness of these coatings was assessed by the electrical conductivity (EC) and phosphorus release (PR) in a kinetic experiment. The kinetic study was carried out in a controlled environment (± 25 °C), following the release pattern of P from 1.5 g of fertilizer in 50 mL of H2O, with and without the coatings. The objective of this work was to study different lignin-based coatings and the phosphorus release behavior of the resulting fertilizer. EC showed to be an effective method of indirect analysis of P releasing from coated MAP. The BL coating presented better results than the CA in terms of controlling the release of P, and the higher the coating ratio (1.0 and 2.0 %) the slower the release of P.
Pages 782-787 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2180
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Agronomic characteristics of soybean under the production and decomposition of sunflower and Paiaguas palisadegrass biomass in different integrated production systems
Itamar Pereira de Oliveira, Kátia Aparecida de Pinho Costa*, Renato Lara de Assis, Eduardo da Costa Severiano, Mariana Borges de Castro Dias, Charles Barbosa dos Santos
Goiano Federal Institute, Graduate Program in Agricultural Sciences, Rio Verde, Goiás, Brazil
Goiano Federal Institute, Iporá, Goiás, Brazil
Abstract
With the adoption of integrated production systems, relative gains in soybean yield have been achieved due to the permanence of vegetal residues on the soil surface. These residues favour the soil microbiota responsible for the decomposition of organic matter and nutrient cycling, which makes integrated agrosystems sustainable. The objective of this study was to evaluate the agronomic characteristics of soybeans under the production and decomposition of sunflower and Paiaguas palisadegrass biomass in different integrated production systems. The experiment was conducted off season in a dystroferric Red Latosol soil in a randomized block experimental design with four replicates. The treatments consisted of the following forage systems: monocropped sunflowers; monocropped Paiaguas palisadegrass; row sunflowers x Paiaguas palisadegrass; inter-row sunflowers x Paiaguas palisadegrass; and oversown sunflowers x Paiaguas palisadegrass. The results showed that the monocropped sunflower and Paiaguas palisadegrass presented the highest biomass production throughout the soybean development cycle, with the slowest decomposition, representing a strategy to increase soil cover efficiency mainly in the period prior to summer planting. The soybean cultivated in the biomass of the monocropped Paiaguas palisadegrass and the Paiaguas palisadegrass intercropped in rows and in inter-rows presented better yields and was positively influenced by the production parameters compared with soybean cultivated otherwise. Therefore, sunflower intercropped with Paiaguas palisadegrass during the off season in the Central-West Region of Brazil was shown to be a promising and sustainable cultivation technique for the production of biomass for no-tillage systems.
Pages 788-794 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2229
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Factors influencing the germination and emergence of tall windmill grass (Chloris polydactyla) and swollen fingergrass (Chloris barbata)
Alfredo Junior Paiola Albrecht, Arthur Arrobas Martins Barroso, Henrique Fabrício Placido, André Felipe Moreira Silva*, Leandro Paiola Albrecht, Fábio Henrique Krenchinski, Ricardo Victoria Filho, Luisa Carolina Baccin
Federal University of Paraná, Palotina, Paraná, Brazil
Federal University of Paraná, Curitiba, Paraná, Brazil
State University of Maringá, Maringá, Paraná, Brazil
University of São Paulo, “Luiz de Queiroz” College of Agriculture, Piracicaba, São, Paulo, Brazil
São Paulo State University "Júlio de Mesquita Filho", Botucatu, São Paulo, Brazil
Abstract
This study characterized the germination of seeds of Chloris polydactyla and Chloris barbata at varying temperature, luminosity, soil texture and cover. The first experiment were conducted in laboratory to determine the temperature and light effects on germination of these species. The experimental design was a 2x7 factorial, where 2 represents the absence/presence of light and 7 temperatures 15, 20, 25, 30, 35, 40 and 45°C. The second experiment was conducted in greenhouse to determine effect of edaphic factors on seedling emergence, in a 3x6 factorial arrangement, consisting of 3 soil textures (sandy, medium and clayey) and 6 sowing depths (0, 1, 2, 4, 6 and 8 cm). The third experiment was conducted in greenhouse to determine soil cover effects and to evaluate the percentage reduction of dry matter of weeds, where the treatments were mulching with 0, 5, 10, 15 and 20 t ha-1 sugarcane straw. All experiments were conducted in completely randomized design, analyzed separately for each species. No seed was germinated under absence of light. Both species achieved better germination in medium textured soil. It was observed that the emergence of the species was low even without straw. Chloris showed better germination under higher temperatures of 30ºC and 35ºC, although exhibited a drastic decline in the emergence with the increase in soil depth or mulching with sugarcane straw. Greater germination of these weeds occurs in medium textured soils.
Pages 795-801 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2243
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Gas exchange, photochemical efficiency, and yield of Jatropha curcas irrigated with saline water
Ivomberg Dourado Magalhães*, Alberto Soares de Melo, Pedro Dantas Fernandes, Messias Firmino de Queiroz, Nair Helena Castro Arriel, Rener Luciano de Souza Ferraz, Janivan Fernandes Suassuna, Sebastião de Oliveira Maia Júnior, Aldair de Souza Medeiros, Pedro Roberto Almeida Viegas, Flavio da Silva Costa, Patricia da Silva Costa
State University of Paraíba, Coordination of the Post-Graduate Program in Agricultural Sciences, Campina Grande, 58429-570, Paraíba, Brazil
Federal University of Campina Grande, Academic Unit of Agricultural Engineering, Campina Grande, 58109-970, Paraíba, Brazil
State University of Paraíba, Center for Agrarian and Environmental Sciences, Lagoa Seca, 58117-000, Paraíba, Brazil
4Brazilian Agricultural Research Corporation, Embrapa Algodão, Campina Grande, 58428-095, PB, Brazil
Federal University of Amapá, Field Education Coordination, Mazagão, 68940-000, Amapá, Brazil
Federal University of Alagoas, Department of Plant Production, Maceió, 57072-900, Alagoas, Brazil
Federal University of Sergipe, Department of Agronomic Engineering, São Cristóvão, 49100-000, Sergipe, Brazil
Fellow of CAPES Postdoctoral, PNPD, Brazil
Fellow of CNPq Research Productivity, level 2, Brazil
Fellow of CNPq Research Productivity, level 1C, Brazil
Fellow of CNPq Postdoctoral, PDJ, Brazil
Abstract
Jatropha curcas L. is a rustic plant with great potential for energy source. In semi-arid regions, where water scarcity has been one of the major problems, saline water is an alternative source in agriculture, although it causes losses in crop development and yield. This study was developed to evaluate the photochemical efficiency, gas exchange, and yield of Jatropha curcas irrigated with saline water. The experiment was carried out under five levels (L) of water electrical conductivity: L1 = 1.2, L2 = 1.8, L3 = 2.4, L4 = 3.0, and L5 = 3.6 dS m-1, (calibrated at 25 ºC). We conducted physiological assessments such as photochemical efficiency of photosystem II, gas exchange through stomatal conductance, transpiration, CO2 internal concentration and leaf net photosynthesis rate after application of saline water and following prunning. J. curcas production was measured based on the following variables, number of bunches per plant, number of fruits per plant, number of fruits per bunch, weight of shells per plant and weight of seeds per plant. Continuous application of saline water after J. curcas pruning caused a drastic reduction of up to 31.1% in gas exchange (A, gs, E, Ci, and A/Ci). Photochemical efficiency of photosystem II was restricted by salinity at 2.4 dS m-1 level. Increasing electrical conductivity in irrigation water at levels above 1.20 dS m-1 significantly reduced J. curcas production components by up to 77.3%. Irrigation with saline water up to the level 1.20 dS m-1 did not damage gas exchange and fruit production of Jatropha curcas crop.
Pages 802-809 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2247
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Cotton is a promising crop for soil sustainability
Emanoel Costa Alves, Mayara Andrade Souza*, Alberício Pereira Andrade, Nair Helena de Castro Arriel, Fábio Aquino Albuquerque, Riselane Lucena de Alcântara Bruno
Federal University of Lavras, Postgraduate Program in Entomology, Lavras, MG 37200-900, Brazil
Center University Cesmac, Postgraduate Program Environmental Systems Analysis, Maceió, AL 57 051-160, Brazil
Federal University Rural of Pernambuco, Department of Animal Production, Garanhuns, PE, Brazil
Embrapa Cotton, Campina Grande, PB 58 428-095, Brazil
Federal University of Paraiba, Postgraduate Program in agronomy, Areia, PB 58397-000, Brazil
Abstract
The coloured cotton crop is the best agroecological alternatives for farmers in semi-arid of Northeasthern region. Cultivation of BRS Verde cotton has been a success on productivity in this region. The practice of monoculture in cotton crop has caused loss of soil quality over the years. The organisms present in the soil are sensitive to changes of land use and management. They are excellent environmental bio indicators, representing important tool to evaluate impacts on ecosystems. In this context, the aim of this research was to evaluate the abundance and diversity of edaphic macrofauna under different management systems in the cotton crop. The design was a randomized complete block design with four replicates with five treatments in 5 collection seasons. The plots consisted of 8 lines spaced 1.0 x 0.30 m for all crops. Three PROVID traps were distributed to capture soil organisms, totally 12 samples/treatments. We identified taxonomic groups, density of organisms, ecological indexes of diversity and wealth of groups. In view of the results, we concluded that the cotton + maize consortium favoured increase of individual’s abundance and richness of faunistic groups. This cotton + maize consortium showed to be a promising alternative for better management and sustainability of the system. We also showed that soil macrofauna is a good indicator of soil quality in different cotton growing systems.
Pages 810-815 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2246
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Overcoming seed dormancy and rooting in air-layering polyembryonic seedlings of sapucaia (Lecythis pisonis Cambess.)
Caroline Palacio de Araujo*, Rodrigo Sobreira Alexandre, Thuanny Lins Monteiro Rosa, Edilson Romais Schmildt, José Carlos Lopes, José Eduardo Macedo Pezzopane
Federal University of Espírito Santo, Departamento de Ciências Florestais e da Madeira, Av. Governador Lindemberg, CEP 29550-000, Jerônimo Monteiro, ES, Brazil
Federal University of Espírito Santo, Departamento de Ciências Agrárias e Biológicas, Rodovia BR-101 Norte, Litorâneo, CEP 29932-540, São Mateus, ES, Brazil
Federal University of Espírito Santo, Departamento de Agronomia, Alto Universitário, Guararema, CEP 29500-000, Alegre, ES, Brazil
Abstract
Lecythis pisonis produces edible seeds rich in nutritional and functional elements such as selenium and are a great alternative to Brazilian nuts. The seeds have low germination, which may be related to physical dormancy imposed by tegument, meaning that polyembryonic seedlings can be a strategy to increase final stand. The objective of this work was to study methods to overcome seed dormancy and auxin induction in polyembryonic seedlings of L. Pisonis. The experiment to break dormancy consisted of seven treatments: T1: intact seeds; T2: seeds scarified on hilum’s opposite side; T3: seeds scarified hilum’s adjacent region; T4: seeds scarified in lateral region; T5: seeds scarified in both opposite and adjacent region to the hilum; T6: T2 + immersion in water at 40 ºC/20 minutes; T7: T2 + immersion in water at 60 ºC/5 minutes. The experiment to induce rooting was arranged in a 2 x 6 factorial randomized complete block design (environments: A. greenhouse and B. greenhouse covered with black polyolefin (80% shading) x concentrations of indole-3-butyric acid (IBA): 0; 1000; 2000; 3000; 4000 and 5000 mg L-1), with four replicates of eight polyembryonic seedlings. Seed coat scarification in hilum’s adjacent (T3) and lateral regions (T4) was the most efficient methods for breaking physical dormancy. IBA at 5000 mg L-1 promoted the greatest rhizogenesis of L. pisonis layers.
Pages 816-821 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2262
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Optimization of the tetrazolium test in three species of orchids of the Andean forest
Seir Antonio Salazar Mercado, Jesús David Quintero Caleño*, Jhan Piero Rojas Suárez
Department of Biology, Universidad Francisco de Paula Santander, Avenida Gran, Colombia #12E-96B Colsag, San José de Cúcuta, Norte de Santander, Postal Code:540003, Colombia
Department of Agricultural Sciences, Universidad Francisco de Paula Santander, Avenida Gran Colombia #12E-96B Colsag, San José de Cúcuta, Norte de Santander, Postal Code:540003, Colombia
Department of Civil Constructions, Roads, Transportation, Hydraulics and Fluids, Universidad Francisco de Paula Santander, Avenida Gran Colombia #12E-96B Colsag, San José de Cúcuta, Norte de Santander, Postal Code:540003, Colombia
Abstract
In order to improve the cultivation and conservation of orchid species, it is important to assess the physiological quality of orchid seeds. One of the most traditional tests for analysing seed quality is the tetrazolium test, whose effectiveness is known to improve with pre-treatment of the seeds. As a result, this study compared various pre-treatments to determine how efficient they were at optimising the tetrazolium test in seeds belonging to Cyrtochilum aemulun, Elleanthus aurantiacus and Lephantes sp. The experiment was based on five different pre-treatment solutions, after which the seeds were exposed to tetrazolium at two different concentrations and for three different exposure times. First, the seeds were soaked for ten minutes in one of five pre-treatment solutions: chlorine 0.5%, chlorine 1%, deionised water, sucrose solution 10% (w/v) or a control in which no pre-treatment was applied. After pre-treatment, the seeds were soaked in the dark in a tetrazolium solution, either at 0.25% concentration or at 1.0% concentration, and for either 6, 24 or 48 hours. The control seeds exposed to no pre-treatment showed an increase in the viability of Lephantes sp. at significant difference from the pre-treated seeds. Similarly, pre-treatment with 10% sucrose produced an increase in the tetrazolium test’s effectiveness in E.aurantiacus seeds, with significant differences from the control in most treatments. Therefore, the use of sucrose as a pre-treatment is recommended, in addition to increasing the concentration and exposure time of the seeds.
Pages 822-830 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2276
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In vitro response of date palm (Phoenix dactylifera L.) inflorescence explants to high 2iP and 2,4-D concentrations
Juliana Martins Ribeiro, Silvio Lopes Teixeira, Joselita Cardoso de Souza, Brenda Lima Ribeiro, Antônio Bruno Nunes Oliveira, Thiago Francisco de Souza Carneiro Neto, Lucas Silva Rios, Reivandson dos Santos Vieira
Biotechnology Laboratory, Brazilian Corporation of Agricultural Research of the Semiarid Tropics, Petrolina, PE, 56302-970, Brazil - corresponding authors
Biotechnology Laboratory, State University of Bahia, Juazeiro, BA, 48900-000, Brazil
Abstract
One of the major problems related to the implementation of date palm crops in Brazil is propagation. Therefore, the aim of this study was to evaluate the possibility of using tissue culture technique for the in vitro propagation of this species. Hence, the effect of 2iP and 2,4-D on the in vitro response of date palm inflorescence tissues, related to floral bud swelling, callusing, and rhizogenesis, was evaluated. The absence of 2,4-D was more detrimental to the in vitro response of inflorescence bud explants than absence of 2iP. In treatments without addition of 2,4-D to the culture medium, explants did not have swelling, callus or root formation. The treatment containing 150 mg/L 2,4-D in the presence of 1.5 mg/L 2iP initiated explant swelling, and treatments with either 100 mg/L or 150 mg/L 2,4-D, combined with 3.0 mg/L 2iP, were also efficient in stimulating in vitro swelling of inflorescence buds. Rhizogenesis was induced at the highest concentrations of 2,4-D (100 and 150 mg/L), combined with 4.5 mg/L 2iP, and was visually more evident in the treatment containing 150 mg/L 2,4-D + 4.5 mg/L 2iP. These results suggest that even higher concentrations of these two reagents might be efficient in the micropropagation of new existing date palm genotypes in the Submedium São Francisco River Valley.
Pages 831-835 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2317
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Physiological potential of soybean industrially treated with different spray volumes and dry powder
Julia Abati, Cristian Rafael Brzezinski, Claudemir Zucareli, Flávia Werner*, Ademir Assis Henning, Fernando Augusto Henning
Agronomic Sciences Department, State University of Maringá, Umuarama Campus, Estrada da Paca, Zip Code: 87507-190, Umuarama, PR, Brazil
Research Department, GDM Brazil' Genetics S.A., Avenue Anísio Alves Costa, 1860, Downtown, Zip Code: 77500-000, Porto Nacional, TO, Brazil
Agronomy Department, State University of Londrina, Highway Celso Garcia Cid 445 Km 380, Zip Code: 86057-970, Londrina, PR, Brazil
Embrapa Soybean, Brazilian Agricultural Research Corporation, Highway Carlos João Strass, Warta District, Zip Code: 86001-970, Londrina, PR, Brazil
Abstract
The industrial treatment of seeds has favored the development of new technologies such as the use of dry powder. It has made application of spray volumes higher than those used in the conventional treatment. Therefore, this study aimed to assess the effect of industrial treatments at different spray volumes with and without application of dry powder on physiological quality of soybean seeds. A completely randomized experimental design was performed with four replications in a 5x2 factorial arrangement for cultivars BRS 359 RR and BRS 284. The factors were five spray volumes (0, 600, 1200, 1800 and 2400 mL. 100 kg-1) with and without the application of dry powder. The products used to obtain the volumes were fungicides (carbendazim + thiram); insecticides (imidacloprid + thiodicarb); nematicide (abamectin); micronutrients (cobalt, molybdenum and zinc); polymer (peridiam); biostimulant (kinetin + gibberellic acid + 4-indol-3-ylbutyric acid) and inoculant (Bradyrhizobium japonicum). The physiological quality of the seeds was determined by the following assessments: germination, first count of germination test, seedling emergence in sand, emergence speed index, and total length of the seedling shoot and root. The results showed that increased spray volume associated with the application of dry powder in seed treatment reduced the physiological quality of soybean seeds, and spray volumes up to 1200 mL 100 kg-1 in seed treatment without the application of dry powder do not impact the emergence and establishment of soybean seedlings.
Pages 836-841 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2412
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Nitrogen fertilization management in common bean and castor bean intercropping systems
Gisele C. Silva, Marcos Eduardo V. Araujo, Veridiana F.R. Almeida, Rodrigo S.L. Araújo, Amanda Cristina E. Lourenço, Cristiane F. Lisboa, Itamar R. Teixeira*, Maryelle B. Silva, Westefann S. Sousa, Alessandro G. Silva
State University of Goiás, Department of Agricultural Engineering, BR-153, 3105 - Fazenda Barreiro do Meio, Anápolis, Goiás, 75132-400, Brazil
Federal University of Viçosa, Department of Agricultural Engineering, Avenida Peter Henry Rolfs, s/n - Campus Universitário, Viçosa, Minas Gerais, 36570-900, Brazil
State University of Goiás, Department of Agronomy, Vila Dona Nilza, SetorUniversitário, Ipameri, Goiás, 75780-000, Brazil
Federal University of Rio Verde, Department of Agronomy, Fazenda Fontes do Saber Campus Universitário, Rio Verde, Goiás, 75901-970, Brazil
Abstract
The objective of this work was to evaluate the nutrition and agronomic characteristics of common bean and castor bean under intercropping subject of nitrogen fertilization in top dressing. A randomized block design in a 2×2×4 + 4 factorial scheme was used, and there were three replicates. The treatments consisted of two common bean cultivars (Pontal and Pérola), which were intercropped with two castor bean cultivars (Energia and Paraguaçu), and combined with four nitrogen treatments (0, 50, 100 and 200 kg ha-1). Four additional treatments involved bean and castor bean cultivars at a single dosage of 40 kg ha-1 nitrogen. The nitrogen, potassium, calcium, magnesium and sulfur contents in castor bean intercropped with common bean leaves were influenced by nitrogen treatments. For common bean applied as top dressing, the maximum grain yields were 1,122 and 1,024 kg ha-1 for cultivars (cvs.) Pontal and Pérola, respectively, with a dose of 100 kg ha-1 nitrogen. Similar results were observed for castor bean, for whom 100 kg ha-1nitrogen provided the largest number of bunches and number of berries per bunch and the highest grain yield. The maximum values observed were 38 and 27 bunches per plant, 27.6 and 35.4 berries per bunch and 1,474 and 1,286 kg ha-1 grain yield for cvs. Paraguaçu and Energia, respectively.
Pages 842-851 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2414b
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Phenology of Croton blachetianus Baill in a dry tropical forest associated with the dynamics of temporal variability of rainfall
Alberício Pereira de Andrade, João Luciano de Andrade Melo Junior*, Riselane de Lucena Alcântara Bruno, André Luiz Rodrigues Magalhães, Luan Danilo Ferreira de Andrade Melo, Divan Soares da Silva, Roberta de Lima Valença
Rural Federal University of Pernambuco, Garanhuns Academic Unit, Av. Bom Pastor, s/n – Boa Vista, Garanhuns, PE, Brazil
Federal University of Paraíba, Center of Agricultural Sciences, 12 Highway, PB-079, Areia, PB, Brazil
Federal University of Alagoas, Center of Agricultural Sciences, BR-104, Rio Largo, AL, Brazil
Abstract
In the semi-arid environment, the synchronism and the magnitude of the precipitation pulses are indispensable for the ecological processes, mainly due to the availability of water in the soil for the plants and to the microbiological activity of the soil. The present study aimed to determine the vegetative and reproductive phenological behavior of Croton blachetianus Baill in areas of Caatinga. The hypothesis was that the occurrence of the phenophases is synchronized with the spatial and temporal distribution of the precipitation pulses, under semi-arid conditions. For the phenological study, 50 tree individuals were selected, marked and monitored weekly, recording the presence and absence of the phenophases of sprouting, appearance of flower buds, flowering (anthesis), fruiting and senescence, whose data were related to the water pulses and inter-pulses. The method proposed by Fournier was used to estimate the percentage of the intensity of the phenophases in each individual. The phenological data of intensity of each phenophase (sprouting, flower-bud, flowering, fruiting and senescence) were related to the distribution of rain pulses and through Spearman’s correlation coefficient, using the number of individuals under each phenophase and the daily climate data. The vegetative and reproductive phenological behavior of C. blachetianus reflected the seasonal pattern of precipitation. The intensity and duration of the phenophases depended on the extent and frequency of the rain pulses during the rainy season. Total leaf senescence happened when the precipitation inter-pulses intensified as the dry season progressed, characterizing deciduousness.
Pages 852-856 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2419
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Cadmium toxicity and phytoremediation in trees - A review
Susana Silva Conceição, Flávio José Rodrigues Cruz*, Edson Ugulino Lima, Vittorio Ugulino Lima, Jéssica Suellen Silva Teixeira, Diana Jhulia Palheta de Sousa, Tiago Kesajiro Moraes Yakuwa, Antônio Vinícius Correa Barbosa, Cândido Ferreira de Oliveira Neto
Universidade Federal Rural da Amazônia, Grupo de Pesquisa Estudos da Biodiversidade de Plantas Superiores, Belém, Pará - Brasil
Universidade Federal Rural de Pernambuco, Programa de Pós-Graduação em Ciência do Solo, Recife, Pernambuco - Brasil
Universidade Federal do Pará - Programa de Pós-Graduação em Diversidade e Agricultura Familiar, Belém, Pará - Brasil
Escola Superior da Amazônia – ESAMAZ, Belém, Pará - Brasil
Universidade Federal Rural da Amazônia- Programa de Pós-Graduação em Agronomia, Belém, Pará - Brasil
Universidade Federal Rural da Amazônia- Instituto Ciberespacial, Belém, Pará - Brasil
Abstract
Over time, the anthropic activity has contributed to alter biogeochemical cycle of heavy metals by releasing contaminants into water, soil and air. Due to contamination of environments with heavy metals, plants and animals consumed by population have presented some level of contamination, which has caused worries and also attempts to minimize these problem. Among heavy metals, cadmium is one of the most toxic to living creatures, occupying seventh position in toxic substances ranking, even with very low concentrations. One of measures adopted to reduce negative impact of soil contamination by heavy metals is phytoremediation. It consists of use of plants that tolerate presence of heavy metals in soil, absorbing, translocating and compartmentalizing them in aerial part, with little or no negative impact on plant growth. Among plants, trees are the most suitable for phytoremediation due to their considerable production of air biomass, which is associated with higher accumulation and consequently higher extraction of heavy metals. In this review, we address main nutritional, biochemical, physiological and molecular aspects of cadmium toxicity in plants, emphasizing role of trees in phytoremediation studies, especially recent studies on Khaya ivorensis or african mahogany and its cadmium phytoremediation potential.
Pages 857-870 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2477
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Two contrasting patterns of crop seasonal adaptation revealed by a common garden experiment on flood recession sorghum in the Sahel
FOKOU YEMATA Oberline, SAÏDOU Abdoul-Aziz, KANMEGNE Gabriel, BERKOULA Orphé, AUDEBERT Alain, SINE Bassirou, FONCEKA Daniel, JOLY Hélène I
CIRAD, UMR AGAP, F-34398 Montpellier, France
AGAP, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
Centre d’Etudes Régional pour l’Amélioration de l’Adaptation à la Sécheresse (CERAAS); Institut Sénégalais de Recherche Agronomique (ISRA), BP 3320, Route de Khombole, Thiès; Senegal
Département de Biologie Végétale, Faculté des Sciences, Université de Dschang, BP 67 Dschang, Cameroon;
Département de Biologie végétale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar Senegal
Former address: Unité Mixte de Recherche “Diversité et Adaptation des Plantes”, Faculté des Sciences et Techniques, Département de Biologie, Université Dan Dicko Dankoulodo de Maradi; BP 465, Maradi Niger
Abstract
Studying seasonal adaptation is of great importance for understanding crop diversification. The biological process of seasonal adaptation of sorghum (Sorghum bicolor (L.) Moench.) allowed the development of flood recession agrosystems in the Sahel (West and Central Africa). To analyze the patterns of trait variation linked to this poorly documented process, we evaluated and compared four eco-seasonal groups of sorghum originating from seasonally diversified agrosystems in the same cropping conditions. The muskuwaari and samme groups are composed of landraces adapted to flood recession agrosystems in the Lake Chad Basin (43 accessions) and the Senegal River Valley (14 accessions), respectively. The other two groups are composed of varieties commonly grown in the rainy season (19 accessions from the Lake Chad Basin and 24 accessions from the Senegal River Valley and and surrounding regions). Multivariate analyses based on ten agro-morphological traits structured the sample in two main clusters subdivided into four subclusters. This structure was significantly associated with the eco-seasonal groups, highlighting muskuwaari differentiation. Five traits (head appearance, leaf length, leaf number, aboveground biomass, and the root mass to aboveground biomass ratio) supported the differentiation of eco- seasonal groups and backed the hypothesis of seasonal adaptive divergence of sorghum in the Lake Chad Basin. No trait differentiation was detected in the samme group, suggesting that seasonal adaptation in the Senegal River Valley might probably be associated with population plasticity existing in the rainy season groups. These experimental evidences provide new insights for understanding scenarios of seasonal adaptation of sorghum.
Pages 871-879 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2442
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Genetic and nutritional diversity of Bacillus subtilis isolates demonstrating different aspects related to plant growth promotion
Bianca de Melo Silveira dos Santos, Maura Santos dos Reis de Andrade Silva, Davy William Hidalgo Chávez, Everlon Cid Rigobelo
Graduate Program in Agricultural Microbiology, Faculty of Agrarian and Veterinary Sciences, State University of São Paulo (UNESP), Jaboticabal, Brazil
Graduate Program in Food Science and Technology, Federal Rural University of Rio de Janeiro (PPGCTA-UFRRJ), Seropédica, Brazil
Abstract
Currently, agricultural practices have been undergoing intense transformations, imposing major challenges such as maintaining productivity with lower production costs and environmental impacts. One of the alternatives to meet these requirements is the use of plant growth promoting bacteria, including Bacillus subtilis. However, different isolates may express different aspects and levels of plant growth promotion. The present study aimed to verify the genetic and nutritional diversity of eight B. subtilis isolates, demonstrating different aspects and levels of plant growth promotion. Eight B. subtilis isolates were analyzed as to their nutritional diversity by BiologEcoPlate TM kit, genetic diversity by Box-PCR, and a trial in greenhouse conditions. The experimental design in greenhouse trial was completely randomized with 9 treatments and five replicates, resulting in 45 pots. Treatments were eight Bacillus subtilis strains, and a control treatment using plants without bacterial inoculation. Isolates 290 and 287 are genetically similar, while isolates 248 and 263 also showed similarity. Genetic and substrate consumption (carbon) analyses showed differences and similarities among isolates, allowing the distribution of isolates into different groups. It was observed that the isolate with the highest ability to promote plant growth was the only isolate that consumed glycyl-L- glutamic acid. These results open the way for further investigations in an attempt to clarify what are the conditions and / or characteristics required by isolates for the plant growth promotion to be more effective.
Pages 880-888 | Full Text PDF| doi: 10.21475/ajcs.20.14.05.p2671