Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P363-366
Tayla Évellin Oliveira, M. Resende, L. A. Florentino, N. C. D. Silva
The angular leaf spot caused by the fungus Pseudocercospora griseola (Sacc.) is one of the main diseases in bean plants. Considering the losses caused by this disease, rhizobacteria may be an alternative for the management of this phytopathogen. Thus, this study evaluates the potential of different strains of rhizobacteria in the inhibition of the fungus P. griseola (Sacc.). The antagonistic effect of twenty bacterial strains on this phytopathogen was studied using the circle technique. The completely randomized experimental design was used with five repetitions. Evaluation was performed on the tenth day, when colony diameter was measured and the percentage of growth inhibition (PGI) of the pathogen was calculated. Twelve strains inhibited the mycelial growth of P. griseola (Sacc.), with PGI values above 40% compared to the control. The strain UNIFENAS 03-36 stood out with inhibition percentage of 85.10%.
{"title":"Antagonistic activity of rhizobacteria in the inhibition of the fungus Pseudocercospora griseola (Sacc.)","authors":"Tayla Évellin Oliveira, M. Resende, L. A. Florentino, N. C. D. Silva","doi":"10.15361/1984-5529.2020V48N4P363-366","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P363-366","url":null,"abstract":"The angular leaf spot caused by the fungus Pseudocercospora griseola (Sacc.) is one of the main diseases in bean plants. Considering the losses caused by this disease, rhizobacteria may be an alternative for the management of this phytopathogen. Thus, this study evaluates the potential of different strains of rhizobacteria in the inhibition of the fungus P. griseola (Sacc.). The antagonistic effect of twenty bacterial strains on this phytopathogen was studied using the circle technique. The completely randomized experimental design was used with five repetitions. Evaluation was performed on the tenth day, when colony diameter was measured and the percentage of growth inhibition (PGI) of the pathogen was calculated. Twelve strains inhibited the mycelial growth of P. griseola (Sacc.), with PGI values above 40% compared to the control. The strain UNIFENAS 03-36 stood out with inhibition percentage of 85.10%.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45434271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P302-310
Samuel Gonçales Ferreira dos Santos, Vinicius Gonçalves de Almeida, Dennis Ricardo Cabral Cruz, R. S. Rodovalho
Os graos de cafe ( Coffea spp.) apresentam longevidade altamente dependente da disponibilidade de agua em seu interior, sendo que o incremento do teor de agua das mesmas pode prejudicar o armazenamento devido ao provavel aparecimento de microrganismos. O estudo das propriedades termodinâmicas proporciona o conhecimento da afinidade do sorvente pela agua e da espontaneidade do processo de sorcao, sendo parâmetros de suma importância no processo de secagem, na analise de projetos de equipamentos, processos de preservacao e acondicionamento de graos. Objetivou-se, com o presente trabalho, determinar e avaliar as propriedades termodinâmicas em graos de Coffea arabica, com teores de agua de equilibrio na faixa de 1,91 a 25,34% base seca (b.s.) e atividade de agua entre 0,10 a 0,83 (decimal), nas temperaturas de 30, 40, 50 e 60 °C. O calor latente de vaporizacao, a entropia diferencial e a energia livre de Gibbs aumentam com a reducao do teor de agua dos graos. A temperatura isocinetica de 498,3433 ± 5,7013 K confirma a compensacao quimica linear entre a entalpia e a entropia diferenciais dos graos de Coffea arabica , sendo o processo de adsorcao dos graos controlado pela entalpia. A adsorcao da agua nos graos de Coffea arabica e um processo nao espontâneo.
{"title":"Propriedades termodinâmicas da adsorção de água de grãos de Coffea arabica L.","authors":"Samuel Gonçales Ferreira dos Santos, Vinicius Gonçalves de Almeida, Dennis Ricardo Cabral Cruz, R. S. Rodovalho","doi":"10.15361/1984-5529.2020V48N4P302-310","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P302-310","url":null,"abstract":"Os graos de cafe ( Coffea spp.) apresentam longevidade altamente dependente da disponibilidade de agua em seu interior, sendo que o incremento do teor de agua das mesmas pode prejudicar o armazenamento devido ao provavel aparecimento de microrganismos. O estudo das propriedades termodinâmicas proporciona o conhecimento da afinidade do sorvente pela agua e da espontaneidade do processo de sorcao, sendo parâmetros de suma importância no processo de secagem, na analise de projetos de equipamentos, processos de preservacao e acondicionamento de graos. Objetivou-se, com o presente trabalho, determinar e avaliar as propriedades termodinâmicas em graos de Coffea arabica, com teores de agua de equilibrio na faixa de 1,91 a 25,34% base seca (b.s.) e atividade de agua entre 0,10 a 0,83 (decimal), nas temperaturas de 30, 40, 50 e 60 °C. O calor latente de vaporizacao, a entropia diferencial e a energia livre de Gibbs aumentam com a reducao do teor de agua dos graos. A temperatura isocinetica de 498,3433 ± 5,7013 K confirma a compensacao quimica linear entre a entalpia e a entropia diferenciais dos graos de Coffea arabica , sendo o processo de adsorcao dos graos controlado pela entalpia. A adsorcao da agua nos graos de Coffea arabica e um processo nao espontâneo.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45992086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P357-362
Eduardo Sávio Gomes Carnimeo, Luiz Eduardo Tilhaqui Bertasello, S. Dutra, G. V. Môro
Constant advances in studies on the behavior of maize genotypes and their interactions with the environment are of great importance for the best performance of the plant. This study verifies effects and causes of agronomic variables of maize hybrids on grain yields and performs the indirect selection of superior genotypes by principal component analysis (PCA). Two hundred and thirty maize genotypes were used, with two hundred and twenty- -nine topcross hybrids (consisting of crossings of two hundred and twenty-nine partially inbred genotypes with a tester) and one check in a randomized block design with two repetitions. The genotypes were evaluated during the 2016 and 2016/2017 crops considering the agronomic variables plant height, ear insertion height, ear position, lodging, breakage, and grain yield. Data were submitted to analysis of variance and means were compared by the Scott-Knott test (p<0.05) with subsequent multivariate exploratory analysis by PCA. In the principal component analysis, components explained 52.07% and 55.69% of the variance contained in the original variables for the 2016 and 2016/2017 crops, respectively. The variable that was most significant in both crops was ear insertion height, allowing the indirect selection of more productive genotypes. Indirect selection of the most productive genotypes was also conducted through variables that contributed significantly in the principal component analysis. Thus, the use of multivariate exploratory analysis is efficient in the characterization and selection of maize genotypes evaluated in different crop seasons.
{"title":"Principal component analysis for selection of superior maize genotypes","authors":"Eduardo Sávio Gomes Carnimeo, Luiz Eduardo Tilhaqui Bertasello, S. Dutra, G. V. Môro","doi":"10.15361/1984-5529.2020V48N4P357-362","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P357-362","url":null,"abstract":"Constant advances in studies on the behavior of maize genotypes and their interactions with the environment are of great importance for the best performance of the plant. This study verifies effects and causes of agronomic variables of maize hybrids on grain yields and performs the indirect selection of superior genotypes by principal component analysis (PCA). Two hundred and thirty maize genotypes were used, with two hundred and twenty- -nine topcross hybrids (consisting of crossings of two hundred and twenty-nine partially inbred genotypes with a tester) and one check in a randomized block design with two repetitions. The genotypes were evaluated during the 2016 and 2016/2017 crops considering the agronomic variables plant height, ear insertion height, ear position, lodging, breakage, and grain yield. Data were submitted to analysis of variance and means were compared by the Scott-Knott test (p<0.05) with subsequent multivariate exploratory analysis by PCA. In the principal component analysis, components explained 52.07% and 55.69% of the variance contained in the original variables for the 2016 and 2016/2017 crops, respectively. The variable that was most significant in both crops was ear insertion height, allowing the indirect selection of more productive genotypes. Indirect selection of the most productive genotypes was also conducted through variables that contributed significantly in the principal component analysis. Thus, the use of multivariate exploratory analysis is efficient in the characterization and selection of maize genotypes evaluated in different crop seasons.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41944471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P367-373
Weyla Silva de Carvalho, G. S. Souza, G. S. Brito, V. S. Almeida, J. C. Lima
Guaco is a plant that has secondary metabolites with therapeutic properties of interest in human medicine, mainly due to its action in respiratory tract diseases. Nitrogen is a nutrient that participates in the formation of several compounds considered to be of great importance for plant growth. Its main forms of absorption by plants are ammonium (NH 4 + ) and nitrate (NO 3 - ) ions and unbalanced ratios can change plant growth. This study evaluates the effect of NH 4 + and NO 3 - (100:0; 75:25; 50:50; 25:75, and 0:100) ratios in nutrient solution on the initial growth of Guaco plants. Guaco growth was affected by NH 4 + and NO 3 - ratios. When NH 4 + was supplied as the exclusive N source, Guaco plants reduced dry biomass production, number of leaves, leaf area, specific leaf area, leaf area ratio, total chlorophyll, and chlorophyll a and b indexes. Thus, increasing doses of the NO 3 - ion positively favored the initial growth of Guaco.
{"title":"Ammonium/nitrate ratio in the initial growth of Guaco","authors":"Weyla Silva de Carvalho, G. S. Souza, G. S. Brito, V. S. Almeida, J. C. Lima","doi":"10.15361/1984-5529.2020V48N4P367-373","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P367-373","url":null,"abstract":"Guaco is a plant that has secondary metabolites with therapeutic properties of interest in human medicine, mainly due to its action in respiratory tract diseases. Nitrogen is a nutrient that participates in the formation of several compounds considered to be of great importance for plant growth. Its main forms of absorption by plants are ammonium (NH 4 + ) and nitrate (NO 3 - ) ions and unbalanced ratios can change plant growth. This study evaluates the effect of NH 4 + and NO 3 - (100:0; 75:25; 50:50; 25:75, and 0:100) ratios in nutrient solution on the initial growth of Guaco plants. Guaco growth was affected by NH 4 + and NO 3 - ratios. When NH 4 + was supplied as the exclusive N source, Guaco plants reduced dry biomass production, number of leaves, leaf area, specific leaf area, leaf area ratio, total chlorophyll, and chlorophyll a and b indexes. Thus, increasing doses of the NO 3 - ion positively favored the initial growth of Guaco.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48393111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P325-338
A. M. Fernandes, N. P. Ribeiro
Sweet potato (Ipomoea batatas L.) is a versatile crop, but it is often grown in marginal and low-fertility areas, which reflects storage root yields far below its potential. For this reason, balanced liming and fertilization in sweet potato are essential to increase crop yield. Based on this approach, themes related to the nutritional requirements of sweet potato are presented and discussed considering the main cultivars currently used in Brazil as well as references for rational fertilization management in this crop. Sweet potato is a crop that absorbs large amounts of nutrients during its development cycle, but this should not be used as a prerogative to excessively increase the fertilizer rates applied in this root crop. As a strategy for rational fertilization management, one should take advantage of the ability of this crop to associate with N-fixing microorganisms, thus reducing the use of mineral N. Moreover, it is necessary to encourage the use of organic fertilizer, whether using animal manure or green manure. In addition to increasing storage root yield and improving storage root shape, organic fertilizers can partially replace mineral chemical fertilizers. Studies aimed at updating cultivar-specific potassium and phosphate fertilizer recommendations should also be encouraged, as well as research addressing micronutrient supply for sweet potato. Additional keywords: Ipomoea batatas L.; mineral fertilizer; nutrients; nutritional status; organic fertilizer.
{"title":"Mineral nutrition and fertilization of sweet potato","authors":"A. M. Fernandes, N. P. Ribeiro","doi":"10.15361/1984-5529.2020V48N4P325-338","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P325-338","url":null,"abstract":"Sweet potato (Ipomoea batatas L.) is a versatile crop, but it is often grown in marginal and low-fertility areas, which reflects storage root yields far below its potential. For this reason, balanced liming and fertilization in sweet potato are essential to increase crop yield. Based on this approach, themes related to the nutritional requirements of sweet potato are presented and discussed considering the main cultivars currently used in Brazil as well as references for rational fertilization management in this crop. Sweet potato is a crop that absorbs large amounts of nutrients during its development cycle, but this should not be used as a prerogative to excessively increase the fertilizer rates applied in this root crop. As a strategy for rational fertilization management, one should take advantage of the ability of this crop to associate with N-fixing microorganisms, thus reducing the use of mineral N. Moreover, it is necessary to encourage the use of organic fertilizer, whether using animal manure or green manure. In addition to increasing storage root yield and improving storage root shape, organic fertilizers can partially replace mineral chemical fertilizers. Studies aimed at updating cultivar-specific potassium and phosphate fertilizer recommendations should also be encouraged, as well as research addressing micronutrient supply for sweet potato. Additional keywords: Ipomoea batatas L.; mineral fertilizer; nutrients; nutritional status; organic fertilizer.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43798489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P351-356
Vinícius Duarte Segismundo, Kevyn Belonssi de Oliveira, Jussara Barros Silva, Lucélia Fátima dos Santos, G. V. Môro
Among the countless operations involved in the maize production system, nitrogen fertilization is essential for the crop yield and development. However, due to the costs and negative environmental impacts caused by chemical fertilization, the use of the bacterium Azospirillum brasilense is an alternative to reduce costs and increase yield. Thus, this study evaluates the effect of inoculation of Azospirillum brasilense on the yield components of synthetic varieties of maize. The experiments were carried out at UNESP – Jaboticabal Campus, state of Sao Paulo, Brazil. The randomized block design was used with two replicates, testing forty-six maize genotypes: forty-four synthetic genotypes and two checks. Experiments were performed without nitrogen topdressing and with Azospirillum brasilense inoculation and, with nitrogen topdressing and without Azospirillum brasilense inoculation. Grain yield, average weight of grains, prolificacy, ear length, ear diameter, number of rows and number of grains per row were evaluated. The analysis of combined variance of experiments was performed considering the effects of genotypes, experiments, and the Genotype x Experiment interaction. Using the means from the analysis of variance, the Scott-Knott test was applied at 5% probability for the cases in which the F test was significant. It was found that bacterial inoculation increased yield, average weight of grains, ear diameter, and number of rows, while nitrogen fertilization increased prolificacy, ear length, and number of grains per row.
{"title":"Effect of Azospirillum brasilense on yield components of maize","authors":"Vinícius Duarte Segismundo, Kevyn Belonssi de Oliveira, Jussara Barros Silva, Lucélia Fátima dos Santos, G. V. Môro","doi":"10.15361/1984-5529.2020V48N4P351-356","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P351-356","url":null,"abstract":"Among the countless operations involved in the maize production system, nitrogen fertilization is essential for the crop yield and development. However, due to the costs and negative environmental impacts caused by chemical fertilization, the use of the bacterium Azospirillum brasilense is an alternative to reduce costs and increase yield. Thus, this study evaluates the effect of inoculation of Azospirillum brasilense on the yield components of synthetic varieties of maize. The experiments were carried out at UNESP – Jaboticabal Campus, state of Sao Paulo, Brazil. The randomized block design was used with two replicates, testing forty-six maize genotypes: forty-four synthetic genotypes and two checks. Experiments were performed without nitrogen topdressing and with Azospirillum brasilense inoculation and, with nitrogen topdressing and without Azospirillum brasilense inoculation. Grain yield, average weight of grains, prolificacy, ear length, ear diameter, number of rows and number of grains per row were evaluated. The analysis of combined variance of experiments was performed considering the effects of genotypes, experiments, and the Genotype x Experiment interaction. Using the means from the analysis of variance, the Scott-Knott test was applied at 5% probability for the cases in which the F test was significant. It was found that bacterial inoculation increased yield, average weight of grains, ear diameter, and number of rows, while nitrogen fertilization increased prolificacy, ear length, and number of grains per row.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42195132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P317-324
Luciana Barboza Silva, G. Lopes, Eliane Carneiro, Sammy Nery de Souza, M. L. S. Filho, F. A. Almeida
The objective was to study the effect of ethanolic extracts of the leaves and bark of Anadenathera macrocarpa (angico-preto) on the germination and development of tomato, pepper and maize seedlings. For the bioassays, concentrations of 0, 250, 500 and 1,000 mg mL -1 were used. Fifty seeds of each plant species were used to evaluate daily germination and ten seedlings were used to evaluate growth. The primary root growth of the maize was stimulated by the 250 mg mL -1 concentration of the leaf extract and in the presence of the bark extract the growth was linear. The germination speed index and germination percentage increased when using the concentrations of 615.8 and 724.4 mg mL -1 , respectively. The concentration of 654.9 mg mL -1 increased the hypocotyl length and that of 628.1 mg mL -1 increased the radicle length of pepper. The length of the tomato radicle was influenced by the concentrations; it was shorter as the concentration increased. Therefore, despite acting differently in each species, A. macrocarpa leaf and bark extracts interfere with the germination and growth of the tested crops.
{"title":"Effect of Anadenathera macrocarpa (Benth) Brenan extracts in tomato, pepper and corn seedlings","authors":"Luciana Barboza Silva, G. Lopes, Eliane Carneiro, Sammy Nery de Souza, M. L. S. Filho, F. A. Almeida","doi":"10.15361/1984-5529.2020V48N4P317-324","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P317-324","url":null,"abstract":"The objective was to study the effect of ethanolic extracts of the leaves and bark of Anadenathera macrocarpa (angico-preto) on the germination and development of tomato, pepper and maize seedlings. For the bioassays, concentrations of 0, 250, 500 and 1,000 mg mL -1 were used. Fifty seeds of each plant species were used to evaluate daily germination and ten seedlings were used to evaluate growth. The primary root growth of the maize was stimulated by the 250 mg mL -1 concentration of the leaf extract and in the presence of the bark extract the growth was linear. The germination speed index and germination percentage increased when using the concentrations of 615.8 and 724.4 mg mL -1 , respectively. The concentration of 654.9 mg mL -1 increased the hypocotyl length and that of 628.1 mg mL -1 increased the radicle length of pepper. The length of the tomato radicle was influenced by the concentrations; it was shorter as the concentration increased. Therefore, despite acting differently in each species, A. macrocarpa leaf and bark extracts interfere with the germination and growth of the tested crops.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43493670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P311-316
Marcelo Pezenti, Diogo Luiz Fruet, Dieison Olescowicz, Cristiane Wernke, N. Guerra, A. M. O. Neto
This study evaluates whether the initial application of pendimethalin can increase the efficiency of ioxynil and ACCase inhibitor treatments in controlling weeds in direct seeding onion. The experiment was carried out in a commercial field in Ituporanga city, Santa Catarina State, Brazil. The onion cultivar Bola Precoce was used. The experimental design was in randomized blocks, in a factorial scheme (2 x 3) + 1, with four replications. Treatments consisted of pendimethalin application in the initial stage (0 or 600 g ha -1 ), three treatments based on ioxynil and ACCase inhibitors, sprayed at postemergence (ioxynil + clethodim (formulated as Select ® ); ioxynil + fluazifop; and ioxynil + clethodim (formulated as Poquer ® )), and a weeded control. Pendimethalin was sprayed immediately after onion crop establishment, and postemergence treatments were sprayed when the onion had 3 and 4 leaves (two sequential applications). The following were evaluated: control of Lolium multiflorum , Coronopus didymus , and Galinsoga parviflora , plant stand, bulb diameter, bulb weight, and total bulb yield. All treatments reached 100% control of L. multiflorum . All treatments were ineffective in controlling C. didymus and G. parviflora ; however, the control of these weeds increased after pendimethalin application. The chemical treatments tested did not negatively influence any of the studied onion crop variables. There was a significant difference only for pendimethalin application in the initial stage, which significantly favored the variables under study. Pendimethalin application in the initial onion stage improved weed control and helped in maintaining bulb yield in direct seeding onion.
本研究评价初施戊二甲基灵是否能提高ioxynil和ACCase抑制剂对洋葱直播杂草的防治效果。该实验在巴西圣卡塔琳娜州伊图波兰加市的一个商业领域进行。洋葱品种为早熟桃。试验设计为随机分组，采用因子(2 × 3) + 1，重复4次。处理包括在初始阶段(0或600 g / ha -1)施用二甲甲烷，三种基于ioxynil和ACCase抑制剂的处理，在羽化后喷洒(ioxynil + clethodim(配方为Select®);Ioxynil + fluazifop;和ioxynil + clethodim(配方为Poquer®))，以及除草对照。在洋葱作物建立后立即喷洒二甲甲烷，在洋葱长出3片和4片叶子时(连续两次施用)喷洒出苗期处理。评价了对何首乌(Lolium multiflorum)、小冠草(Corono-pus didymus)和小冠草(Galinsoga parviflora)的防治效果、株数、球茎直径、球茎质量和总球茎产量。所有处理对何首乌的控制均达到100%。所有处理对小叶假蝇和小叶假蝇的防治效果均不显著;喷施对这些杂草的抑制作用增强。试验的化学处理对所研究的洋葱作物的任何变量都没有负面影响。只有在初始阶段，喷二甲甲烷的施用有显著差异，这对研究的变量显著有利。在洋葱初苗期施用苯二甲胺可以改善杂草控制，并有助于保持直接播种洋葱的鳞茎产量。
{"title":"Efficiency of pendimethalin, ioxynil, and accase inhibitors in controlling weeds in direct seeding onion","authors":"Marcelo Pezenti, Diogo Luiz Fruet, Dieison Olescowicz, Cristiane Wernke, N. Guerra, A. M. O. Neto","doi":"10.15361/1984-5529.2020V48N4P311-316","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P311-316","url":null,"abstract":"This study evaluates whether the initial application of pendimethalin can increase the efficiency of ioxynil and ACCase inhibitor treatments in controlling weeds in direct seeding onion. The experiment was carried out in a commercial field in Ituporanga city, Santa Catarina State, Brazil. The onion cultivar Bola Precoce was used. The experimental design was in randomized blocks, in a factorial scheme (2 x 3) + 1, with four replications. Treatments consisted of pendimethalin application in the initial stage (0 or 600 g ha -1 ), three treatments based on ioxynil and ACCase inhibitors, sprayed at postemergence (ioxynil + clethodim (formulated as Select ® ); ioxynil + fluazifop; and ioxynil + clethodim (formulated as Poquer ® )), and a weeded control. Pendimethalin was sprayed immediately after onion crop establishment, and postemergence treatments were sprayed when the onion had 3 and 4 leaves (two sequential applications). The following were evaluated: control of Lolium multiflorum , Coronopus didymus , and Galinsoga parviflora , plant stand, bulb diameter, bulb weight, and total bulb yield. All treatments reached 100% control of L. multiflorum . All treatments were ineffective in controlling C. didymus and G. parviflora ; however, the control of these weeds increased after pendimethalin application. The chemical treatments tested did not negatively influence any of the studied onion crop variables. There was a significant difference only for pendimethalin application in the initial stage, which significantly favored the variables under study. Pendimethalin application in the initial onion stage improved weed control and helped in maintaining bulb yield in direct seeding onion.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48970358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-22DOI: 10.15361/1984-5529.2020V48N4P396-402
L. A. P. L. Nunes, Bruno Karvand Ferreira Soares, R. S. Sousa, Thiago Ibiapina, L. R. Barbosa
Scarification improves soil physical conditions, resulting in suitable conditions for root growth in crops and water infiltration. This study evaluates the effects of mechanical scarification on the physical attributes of a Yellow Oxisol cultivated with soybean under no-tillage in the Savanna of Piaui state, Brazil. Three areas under soybean cultivation were chosen, namely: one in the second year of cultivation under no-tillage (CS2); one cultivated for ten years under no-tillage (CS10); one area with soybeans identical to the previous one, but with scarification for a year (ESC); and a native Savana vegetation (CV), used as control. Density, macroporosity, microporosity, total porosity, and soil resistance to penetration at depths between 0-0.20 and 0.20-0.40 m were evaluated. The CS area showed decreased physical indicator values compared to the other management systems. Scarification was efficient in improving soil density, total porosity, and soil resistance to penetration at depths between 0.00 and 0.20 m. CS2 and CV areas showed more favorable physical indicator values. Through multivariate analyses, it was possible to identify which physical variables correlated with each type of soil management and the effects of these managements on the physical characteristics of the soil studied.
{"title":"Physical indicators after mechanical scarification in a Yellow Oxisol under no-tillage","authors":"L. A. P. L. Nunes, Bruno Karvand Ferreira Soares, R. S. Sousa, Thiago Ibiapina, L. R. Barbosa","doi":"10.15361/1984-5529.2020V48N4P396-402","DOIUrl":"https://doi.org/10.15361/1984-5529.2020V48N4P396-402","url":null,"abstract":"Scarification improves soil physical conditions, resulting in suitable conditions for root growth in crops and water infiltration. This study evaluates the effects of mechanical scarification on the physical attributes of a Yellow Oxisol cultivated with soybean under no-tillage in the Savanna of Piaui state, Brazil. Three areas under soybean cultivation were chosen, namely: one in the second year of cultivation under no-tillage (CS2); one cultivated for ten years under no-tillage (CS10); one area with soybeans identical to the previous one, but with scarification for a year (ESC); and a native Savana vegetation (CV), used as control. Density, macroporosity, microporosity, total porosity, and soil resistance to penetration at depths between 0-0.20 and 0.20-0.40 m were evaluated. The CS area showed decreased physical indicator values compared to the other management systems. Scarification was efficient in improving soil density, total porosity, and soil resistance to penetration at depths between 0.00 and 0.20 m. CS2 and CV areas showed more favorable physical indicator values. Through multivariate analyses, it was possible to identify which physical variables correlated with each type of soil management and the effects of these managements on the physical characteristics of the soil studied.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42682218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-29DOI: 10.15361/1984-5529.2020v48n2p147-153
Jair Leão Da Silva Júnior, A. Braz, Paulo Fernandes Boldrin, Camila Jorge Bernabé Ferreira, Pedro Marques Da Silveira
Producing food in a sustainable manner, exploiting the genetic potential of crops and optimizing cultivation time to ensure increased production are the biggest challenges for agriculture. The cultivation of super-early common bean lineages with high productive capacity leads to minor water consumption in crops under irrigation and vacate the area in less time. The objective of this work was to evaluate the yield components of super-early cycle common bean cultivars, under irrigated system in function of sources of nitrogen (N) as well as to assess different application stages. The experiment was conducted in randomized block design in a factorial scheme 4x3 + 1, corresponding of four sources of N in coverage (urea, urea + ammonium sulfate, urea + ammonium sulfate + elemental sulfur and urea + elemental sulfur), three application stages (V3, V4 and R5) and a control treatment. The N incorporation did not influence on the grain yield of the super-early cycle common bean regardless of the source and season, whereas significant results were merely found when compared to the control. The number of pods was affected when the application was carried out at the R5 stage, with a significant reduction in this yield component. The relative chlorophyll index was lower when nitrogen coverage was performed at the R5 stage.
{"title":"Application stages and nitrogen sources in topdressing of super-early bean crop irrigated","authors":"Jair Leão Da Silva Júnior, A. Braz, Paulo Fernandes Boldrin, Camila Jorge Bernabé Ferreira, Pedro Marques Da Silveira","doi":"10.15361/1984-5529.2020v48n2p147-153","DOIUrl":"https://doi.org/10.15361/1984-5529.2020v48n2p147-153","url":null,"abstract":"Producing food in a sustainable manner, exploiting the genetic potential of crops and optimizing cultivation time to ensure increased production are the biggest challenges for agriculture. The cultivation of super-early common bean lineages with high productive capacity leads to minor water consumption in crops under irrigation and vacate the area in less time. The objective of this work was to evaluate the yield components of super-early cycle common bean cultivars, under irrigated system in function of sources of nitrogen (N) as well as to assess different application stages. The experiment was conducted in randomized block design in a factorial scheme 4x3 + 1, corresponding of four sources of N in coverage (urea, urea + ammonium sulfate, urea + ammonium sulfate + elemental sulfur and urea + elemental sulfur), three application stages (V3, V4 and R5) and a control treatment. The N incorporation did not influence on the grain yield of the super-early cycle common bean regardless of the source and season, whereas significant results were merely found when compared to the control. The number of pods was affected when the application was carried out at the R5 stage, with a significant reduction in this yield component. The relative chlorophyll index was lower when nitrogen coverage was performed at the R5 stage.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49588682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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