Pub Date : 2021-07-16DOI: 10.1590/1413-7054202145004821
M. G. F. Rodrigues, A. F. A. Ferreira, E. S. Malagutti, Milena dos Santos Pinto, L. Monteiro, M. E. D. Sá
ABSTRACT Cutting is a propagation method with the advantages of early production and uniform cultivation. Some factors influence propagation and rooting, such as the cutting size and the time of year the collection is performed. Thus, the present work aimed to evaluate the ideal size of white-fleshed red pitahaya cladodes and the time of their collection for crop propagation by cutting in view of the physiological quality of the produced clonal plants to enable more appropriate cultural management and increase the cultivation area. The experiment was conducted at the Faculty of Engineering (UNESP) using three cladode sizes (cuttings) with lengths of 10, 20 and 40 cm collected in two seasons (summer and winter). The experimental design used was completely randomized in a split-time scheme, with no dependence on the factors and 20 replicates. Evaluations of the biometric factors related to sprouts and cladode rooting were carried out 60 days after cutting. According to the results, there were significant differences among treatments, with a significant interaction of the number of sprouts. It can be concluded that, regarding the size of the cladodes, it is recommended, when possible, to use cladodes 40 cm in length; regarding the time of collection, it is recommended that collection be conducted in the winter period to favor the development of better-quality clonal plants.
{"title":"Cladode size and collection time for pitahaya propagation","authors":"M. G. F. Rodrigues, A. F. A. Ferreira, E. S. Malagutti, Milena dos Santos Pinto, L. Monteiro, M. E. D. Sá","doi":"10.1590/1413-7054202145004821","DOIUrl":"https://doi.org/10.1590/1413-7054202145004821","url":null,"abstract":"ABSTRACT Cutting is a propagation method with the advantages of early production and uniform cultivation. Some factors influence propagation and rooting, such as the cutting size and the time of year the collection is performed. Thus, the present work aimed to evaluate the ideal size of white-fleshed red pitahaya cladodes and the time of their collection for crop propagation by cutting in view of the physiological quality of the produced clonal plants to enable more appropriate cultural management and increase the cultivation area. The experiment was conducted at the Faculty of Engineering (UNESP) using three cladode sizes (cuttings) with lengths of 10, 20 and 40 cm collected in two seasons (summer and winter). The experimental design used was completely randomized in a split-time scheme, with no dependence on the factors and 20 replicates. Evaluations of the biometric factors related to sprouts and cladode rooting were carried out 60 days after cutting. According to the results, there were significant differences among treatments, with a significant interaction of the number of sprouts. It can be concluded that, regarding the size of the cladodes, it is recommended, when possible, to use cladodes 40 cm in length; regarding the time of collection, it is recommended that collection be conducted in the winter period to favor the development of better-quality clonal plants.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42100782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-16DOI: 10.1590/1413-7054202145005721
R. L. Ferraz, P. S. Costa, I. D. Magalhães, A. D. S. Medeiros, P. R. A. Viégas, A. S. Melo
ABSTRACT Abiotic stresses reduce the yield and quality of cotton production, however, this problem may be mitigated by exogenous elicitors. This study investigated physiological adjustments, improvement in productivity, and fiber yield and quality from naturally colored cotton BRS Topázio cultivar under leaf silicon spraying. Five doses of silicon (0, 50, 100, 150, and 200 mg L-1) were tested in a completely randomized design. The variables assessed were physiological, production, fiber yield and quality. Data were submitted to principal component analysis, multivariate and univariate variance, and multiple linear regression. Silicon promotes physiological adjustments, increased production, cotton fiber yield and quality. Optimum silicon dose varies depending on the variable response. Fiber quality from plants treated with silicon is within the expected pattern for this cultivar and the international standard D-4605 of the American Society for Testing and Materials. Therefore, planting BRS Topázio cultivar under silicon foliar applications may be recommended to improve the naturally colored fiber cotton production chain in the Brazilian semiarid region.
{"title":"Physiological adjustments, fiber yield and quality of colored cotton BRS Topázio cultivar under leaf silicon spraying","authors":"R. L. Ferraz, P. S. Costa, I. D. Magalhães, A. D. S. Medeiros, P. R. A. Viégas, A. S. Melo","doi":"10.1590/1413-7054202145005721","DOIUrl":"https://doi.org/10.1590/1413-7054202145005721","url":null,"abstract":"ABSTRACT Abiotic stresses reduce the yield and quality of cotton production, however, this problem may be mitigated by exogenous elicitors. This study investigated physiological adjustments, improvement in productivity, and fiber yield and quality from naturally colored cotton BRS Topázio cultivar under leaf silicon spraying. Five doses of silicon (0, 50, 100, 150, and 200 mg L-1) were tested in a completely randomized design. The variables assessed were physiological, production, fiber yield and quality. Data were submitted to principal component analysis, multivariate and univariate variance, and multiple linear regression. Silicon promotes physiological adjustments, increased production, cotton fiber yield and quality. Optimum silicon dose varies depending on the variable response. Fiber quality from plants treated with silicon is within the expected pattern for this cultivar and the international standard D-4605 of the American Society for Testing and Materials. Therefore, planting BRS Topázio cultivar under silicon foliar applications may be recommended to improve the naturally colored fiber cotton production chain in the Brazilian semiarid region.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46684247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-25DOI: 10.1590/1413-7054202145033720
R. Martins, R. Pêgo, E. S. D. Cruz, J. Abreu, D. F. Carvalho
ABSTRACT Zinnia (Zinnia elegans Jacq.) is a fast-growing and easy to cultivate plant that has flowers of different colors. This species has become an option to be introduced commercially in many countries as cut flower and its floral quality is influenced by different cultivation techniques. We evaluated the production and the quality of floral stems of zinnia (cv. Red California Giant) in response to growing seasons and irrigation levels. In a greenhouse located in Rio de Janeiro (Brazil), zinnia plants were grown in two cycles (autumn-winter and winter-spring) in pots with water replacement corresponding to 46, 64, 75 and 100% of their water requirement. Based on the stem length and diameter and on the flower diameter, there was variation in the quality of the stems produced in the growing seasons evaluated. All stems from the autumn-winter cycle were classified as A1 (high quality), while almost 9% of the stems from the winter-spring cycle were classified as A2 (medium quality). There was a linear growth trend in the production and quality of zinnia stems with the increase of the irrigation level in most cases, as well as significant effect of the growing seasons, with the best results of number of stems, fresh weight, length and diameter of the stem and flower diameter found in the autumn-winter cycle. The weather conditions of this cycle favor the production and quality of zinnia floral stems, and the replacement of 100% of the specie’s water requirement is recommended in both cultivation cycles.
{"title":"Production and quality of zinnia under different growing seasons and irrigation levels","authors":"R. Martins, R. Pêgo, E. S. D. Cruz, J. Abreu, D. F. Carvalho","doi":"10.1590/1413-7054202145033720","DOIUrl":"https://doi.org/10.1590/1413-7054202145033720","url":null,"abstract":"ABSTRACT Zinnia (Zinnia elegans Jacq.) is a fast-growing and easy to cultivate plant that has flowers of different colors. This species has become an option to be introduced commercially in many countries as cut flower and its floral quality is influenced by different cultivation techniques. We evaluated the production and the quality of floral stems of zinnia (cv. Red California Giant) in response to growing seasons and irrigation levels. In a greenhouse located in Rio de Janeiro (Brazil), zinnia plants were grown in two cycles (autumn-winter and winter-spring) in pots with water replacement corresponding to 46, 64, 75 and 100% of their water requirement. Based on the stem length and diameter and on the flower diameter, there was variation in the quality of the stems produced in the growing seasons evaluated. All stems from the autumn-winter cycle were classified as A1 (high quality), while almost 9% of the stems from the winter-spring cycle were classified as A2 (medium quality). There was a linear growth trend in the production and quality of zinnia stems with the increase of the irrigation level in most cases, as well as significant effect of the growing seasons, with the best results of number of stems, fresh weight, length and diameter of the stem and flower diameter found in the autumn-winter cycle. The weather conditions of this cycle favor the production and quality of zinnia floral stems, and the replacement of 100% of the specie’s water requirement is recommended in both cultivation cycles.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43244355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-25DOI: 10.1590/1413-7054202145004721
Laura Raquel Orozco Meléndez, O. A. H. Rodríguez, O. C. Alvarez, A. Mendoza, Marisela Calderón Jurado, Damaris Leopoldina Ojeda Barrios
ABSTRACT Carya illinoinensis (Wangenh.) K. Koch. is a deciduous fruit species with high economic impact and nutritional value that exhibits alternate bearing behavior. In this study, the concentration of foliar nutrients, non-structural carbohydrates and yield were evaluated in cultivar Western Schley pecan in response to the foliar application of gibberellic acid (50 mg L-1 GA3), prohexadione calcium (500 mg L-1 PCa) and thidiazuron (10 mg L-1 TDZ).The statistical analysis reveals that between agricultural cycles, the treatments showed no variation in the foliar concentration of nitrogen total (N-total), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), manganese (Mn) and non-structural carbohydrates (fructose, glucose, sucrose and starch). However, the application of PCa showed no significant effect on the concentration of phosphorus (P) (1.5 and 1.9 g kg-1). On the other hand, the concentration of zinc (Zn) (27.0-60.1 mg kg-1) showed a significant difference between years, with no effect due to the application of growth bioregulators. The trees treated with GA3 minimized alternate bearing by presenting similar values (12.4 and 15.3 kg tree-1) of yield. Likewise, the applied treatments did not affect the nut weight per kilogram (kg) (5.5-6.8 g) and kernel percentage (56.5-60.8). These data provide a new perspective on the complex nature of alternate bearing production in cultivar Western Schley pecan and are interpreted to indicate that alternate production could be regulated by carbohydrate reserve, nutrient concentration, and gibberellins.
{"title":"Does the application of growth bioregulators improve the foliar concentration of nutrients, non-structural carbohydrates and yield in pecan?","authors":"Laura Raquel Orozco Meléndez, O. A. H. Rodríguez, O. C. Alvarez, A. Mendoza, Marisela Calderón Jurado, Damaris Leopoldina Ojeda Barrios","doi":"10.1590/1413-7054202145004721","DOIUrl":"https://doi.org/10.1590/1413-7054202145004721","url":null,"abstract":"ABSTRACT Carya illinoinensis (Wangenh.) K. Koch. is a deciduous fruit species with high economic impact and nutritional value that exhibits alternate bearing behavior. In this study, the concentration of foliar nutrients, non-structural carbohydrates and yield were evaluated in cultivar Western Schley pecan in response to the foliar application of gibberellic acid (50 mg L-1 GA3), prohexadione calcium (500 mg L-1 PCa) and thidiazuron (10 mg L-1 TDZ).The statistical analysis reveals that between agricultural cycles, the treatments showed no variation in the foliar concentration of nitrogen total (N-total), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), manganese (Mn) and non-structural carbohydrates (fructose, glucose, sucrose and starch). However, the application of PCa showed no significant effect on the concentration of phosphorus (P) (1.5 and 1.9 g kg-1). On the other hand, the concentration of zinc (Zn) (27.0-60.1 mg kg-1) showed a significant difference between years, with no effect due to the application of growth bioregulators. The trees treated with GA3 minimized alternate bearing by presenting similar values (12.4 and 15.3 kg tree-1) of yield. Likewise, the applied treatments did not affect the nut weight per kilogram (kg) (5.5-6.8 g) and kernel percentage (56.5-60.8). These data provide a new perspective on the complex nature of alternate bearing production in cultivar Western Schley pecan and are interpreted to indicate that alternate production could be regulated by carbohydrate reserve, nutrient concentration, and gibberellins.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41837329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-25DOI: 10.1590/1413-7054202145000121
Melina Korres Raimundi, R. M. Souza, A. R. Figueira, Gustavo Matheus Silva, Ana Carolina de Paula Santos, Sarah S. C. Guimarães
ABSTRACT The diagnosis of foliar bacterial diseases in coffee (Coffea arabica), such as halo blight (Pseudomonas syringae pv. garcae), bacterial leaf spot (P. syringae pv. tabaci), bacterial blight (P. cichorii), and dark leaf spot (Robbsia andropogonis), is considered a challenge for plant pathologists. The misidentification has been occurring when the diagnosis is solely based on symptoms and biochemical properties. Thus, the objective of this study was to identify and differentiate species and pathovars of Pseudomonas pathogenic to coffee plants, enabling a survey of the occurrence of these bacteria in the main producing regions of Minas Gerais state, Brazil. Firstly, the pathogenicity of the isolates was confirmed by inoculation in C. arabica cv. Catuaí Vermelho IAC 99. Then, biochemical analyses, combined with, repetitive element-polymerase chain reaction (rep-PCR) and phylogeny based on rpoD gene sequences were used to characterize 84 Pseudomonas isolates from coffee crops and nurseries. Based on rpoD-phylogeny, 73 isolates were identified as P. syringae pv. garcae, five as P. syringae pv. tabaci and six as P. cichorii. The rep-PCR results suggest a high genetic variability in populations of Pseudomonas syringae pv. garcae and P. cichorii. This is the first report of the occurrence of bacterial leaf spot (P. syringae pv. tabaci) in the coffee-producing filed in Minas Gerais State. The findings confirmed the prevalence of P. syringae pv. garcae in coffee production fields in the State and the generated knowledge will contribute for the development of species-specific primers for the identification and detection of this pathogen.
{"title":"Diagnosis of leaf bacterial diseases of coffee reveals the prevalence of halo blight","authors":"Melina Korres Raimundi, R. M. Souza, A. R. Figueira, Gustavo Matheus Silva, Ana Carolina de Paula Santos, Sarah S. C. Guimarães","doi":"10.1590/1413-7054202145000121","DOIUrl":"https://doi.org/10.1590/1413-7054202145000121","url":null,"abstract":"ABSTRACT The diagnosis of foliar bacterial diseases in coffee (Coffea arabica), such as halo blight (Pseudomonas syringae pv. garcae), bacterial leaf spot (P. syringae pv. tabaci), bacterial blight (P. cichorii), and dark leaf spot (Robbsia andropogonis), is considered a challenge for plant pathologists. The misidentification has been occurring when the diagnosis is solely based on symptoms and biochemical properties. Thus, the objective of this study was to identify and differentiate species and pathovars of Pseudomonas pathogenic to coffee plants, enabling a survey of the occurrence of these bacteria in the main producing regions of Minas Gerais state, Brazil. Firstly, the pathogenicity of the isolates was confirmed by inoculation in C. arabica cv. Catuaí Vermelho IAC 99. Then, biochemical analyses, combined with, repetitive element-polymerase chain reaction (rep-PCR) and phylogeny based on rpoD gene sequences were used to characterize 84 Pseudomonas isolates from coffee crops and nurseries. Based on rpoD-phylogeny, 73 isolates were identified as P. syringae pv. garcae, five as P. syringae pv. tabaci and six as P. cichorii. The rep-PCR results suggest a high genetic variability in populations of Pseudomonas syringae pv. garcae and P. cichorii. This is the first report of the occurrence of bacterial leaf spot (P. syringae pv. tabaci) in the coffee-producing filed in Minas Gerais State. The findings confirmed the prevalence of P. syringae pv. garcae in coffee production fields in the State and the generated knowledge will contribute for the development of species-specific primers for the identification and detection of this pathogen.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45197037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-23DOI: 10.1590/1413-7054202145001721
Gabriela Muricy de Souza Silva, Jessyka Silva da Costa, Janaina Oliveira Freire, L. Santos, R. Bonomo
ABSTRACT The search for origin plant-based proteases increases gradually due to their diversity and stability over a wide range of pH and temperature. Artichoke (Cynara scolymus) flowers are a proteolytic vegetable source already studied, but their leaves are scarce in this respect. Thus, the objective of this research was to obtain extracts of artichoke leaves with different buffers and extraction methods as an alternative proteolytic source and plant coagulant, as well as the separation and comparison of the protein profile of these extracts. The methodology used was based on extraction with sodium citrate buffer (pH 3), sodium acetate (pH 5) and Tris-HCl (pH 7) by mechanical stirrer (MS) and ultrasound (US); protein determination; proteolytic activity (PA) and specific activity (SA); milk clotting activity (MCA) and rennet substitution potential (RSP); high- performance liquid chromatography analysis (HPLC) with UV-Vis detector and principal component analysis (PCA). Extracts of Cynara scolymus leaves showed high results with Citrate-US for the parameters PA (14.38), SA (19.71), MCA (440) and RSP (30.60) compared to other treatments. The extracts with citrate and acetate presented a quick coagulation time (max 3 min). The HPLC analysis enabled the separation of the different protein compounds present in the extracts and most expressive peaks in the samples with Citrate-MS and Acetate-MS; and isolated peaks for Citrate-US. It was concluded that extracts of artichoke leaves with citrate and acetate buffer attributed satisfactory results to act as plant coagulant, as well as to carry out further studies for the purification of proteolytic enzymes and application in cheeses.
{"title":"Artichoke leaf extracts: Proteolytic activity, coagulant and HPLC analysis","authors":"Gabriela Muricy de Souza Silva, Jessyka Silva da Costa, Janaina Oliveira Freire, L. Santos, R. Bonomo","doi":"10.1590/1413-7054202145001721","DOIUrl":"https://doi.org/10.1590/1413-7054202145001721","url":null,"abstract":"ABSTRACT The search for origin plant-based proteases increases gradually due to their diversity and stability over a wide range of pH and temperature. Artichoke (Cynara scolymus) flowers are a proteolytic vegetable source already studied, but their leaves are scarce in this respect. Thus, the objective of this research was to obtain extracts of artichoke leaves with different buffers and extraction methods as an alternative proteolytic source and plant coagulant, as well as the separation and comparison of the protein profile of these extracts. The methodology used was based on extraction with sodium citrate buffer (pH 3), sodium acetate (pH 5) and Tris-HCl (pH 7) by mechanical stirrer (MS) and ultrasound (US); protein determination; proteolytic activity (PA) and specific activity (SA); milk clotting activity (MCA) and rennet substitution potential (RSP); high- performance liquid chromatography analysis (HPLC) with UV-Vis detector and principal component analysis (PCA). Extracts of Cynara scolymus leaves showed high results with Citrate-US for the parameters PA (14.38), SA (19.71), MCA (440) and RSP (30.60) compared to other treatments. The extracts with citrate and acetate presented a quick coagulation time (max 3 min). The HPLC analysis enabled the separation of the different protein compounds present in the extracts and most expressive peaks in the samples with Citrate-MS and Acetate-MS; and isolated peaks for Citrate-US. It was concluded that extracts of artichoke leaves with citrate and acetate buffer attributed satisfactory results to act as plant coagulant, as well as to carry out further studies for the purification of proteolytic enzymes and application in cheeses.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48497609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-23DOI: 10.1590/1413-7054202145001921
C. Yaman, Ş. Şimşek
ABSTRACT The search for new plant natural products with insecticidal properties to control insect pests in agriculture has gained relevance in the past decades. The aim of the study was to investigate the insecticidal activity of extracts derived from flower, leaf, and stem of three Hypericum species (Hypericum heterophyllum, Hypericum perforatum, Hypericum scabrum) against the adults of three important stored grain insect pests namely; Sitophilus oryzae (Curculionidae), Rhyzopertha dominica (Bostrichidae) and Tribolium confusum (Tenebrionidae). The insects were incubated with the food under 10% concentration of Hypericum extracts and the mortality was recorded after 24, 48 and 72 h of exposure. The extracts of the Hypericum species and exposure time were found to have statistically significant effective against the three insect pests. After 72 h exposure, the mortality ranged from 4.3 to 94.1 % for all insects. Among tested insects, R. dominica was more susceptible than T. confusum and S. oryzae. Although desirable insecticidal effect against the insects were recorded from all the three Hypericum species, the leaf extract of H. perforatum was more effective on R. dominica, while the flower and stem of H. scabrum displayed high toxic effect on T. confusum and S. oryzae, respectively. The leaf extracts, of H. perforatum, in particular, may be used as source of new potential botanical insecticides against R. dominica in stored grains.
{"title":"Insecticidal effect of from three Hypericum species extracts against Rhyzopertha dominica, Sitophilus oryzae and Tribolium confusum","authors":"C. Yaman, Ş. Şimşek","doi":"10.1590/1413-7054202145001921","DOIUrl":"https://doi.org/10.1590/1413-7054202145001921","url":null,"abstract":"ABSTRACT The search for new plant natural products with insecticidal properties to control insect pests in agriculture has gained relevance in the past decades. The aim of the study was to investigate the insecticidal activity of extracts derived from flower, leaf, and stem of three Hypericum species (Hypericum heterophyllum, Hypericum perforatum, Hypericum scabrum) against the adults of three important stored grain insect pests namely; Sitophilus oryzae (Curculionidae), Rhyzopertha dominica (Bostrichidae) and Tribolium confusum (Tenebrionidae). The insects were incubated with the food under 10% concentration of Hypericum extracts and the mortality was recorded after 24, 48 and 72 h of exposure. The extracts of the Hypericum species and exposure time were found to have statistically significant effective against the three insect pests. After 72 h exposure, the mortality ranged from 4.3 to 94.1 % for all insects. Among tested insects, R. dominica was more susceptible than T. confusum and S. oryzae. Although desirable insecticidal effect against the insects were recorded from all the three Hypericum species, the leaf extract of H. perforatum was more effective on R. dominica, while the flower and stem of H. scabrum displayed high toxic effect on T. confusum and S. oryzae, respectively. The leaf extracts, of H. perforatum, in particular, may be used as source of new potential botanical insecticides against R. dominica in stored grains.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47177333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-23DOI: 10.1590/1413-7054202145031720
S. P. Jasper, G. G. Zimmermann, D. Savi, Lauro Strapasson Neto, L. L. Kmiecik, L. Sobenko
ABSTRACT The decision-making capability of the machine to harvest grains must consider a lower fuel consumption with a higher operating velocity allied to a greater performance of the grain cleaning system, along with lower rates of the damage and waste produced. This study aimed at evaluating the operational performance and the energy efficiency of two axial harvesters, having different trail and separation systems in the soybean seed harvest. The experiment was carried out in a completely randomized block design in 500-m bands, consisting of two factors, namely two axial harvesters (single and double rotor) and six target velocities (3, 4, 5, 6, 7, and 8 km h-1). Regarding the operational energy performance, the hourly fuel consumption, operational speed, operational field capacity, fuel consumption per area and mass of the harvested grain, and the handling capacity of the harvest were evaluated. The harvesting performance parameters, such as the percentage losses in the platform and the trail system, broken grains, impurities, and the pods, which did not undergo threshing, were evaluated. The results obtained showed that the single-rotor harvester had a better energy efficiency, while the double-rotor harvester had a better operational performance. The double-rotor harvester was agronomically more efficient.
{"title":"Operational performance and energy efficiency of axial harvesters with single and double rotor systems in soybean seed harvest","authors":"S. P. Jasper, G. G. Zimmermann, D. Savi, Lauro Strapasson Neto, L. L. Kmiecik, L. Sobenko","doi":"10.1590/1413-7054202145031720","DOIUrl":"https://doi.org/10.1590/1413-7054202145031720","url":null,"abstract":"ABSTRACT The decision-making capability of the machine to harvest grains must consider a lower fuel consumption with a higher operating velocity allied to a greater performance of the grain cleaning system, along with lower rates of the damage and waste produced. This study aimed at evaluating the operational performance and the energy efficiency of two axial harvesters, having different trail and separation systems in the soybean seed harvest. The experiment was carried out in a completely randomized block design in 500-m bands, consisting of two factors, namely two axial harvesters (single and double rotor) and six target velocities (3, 4, 5, 6, 7, and 8 km h-1). Regarding the operational energy performance, the hourly fuel consumption, operational speed, operational field capacity, fuel consumption per area and mass of the harvested grain, and the handling capacity of the harvest were evaluated. The harvesting performance parameters, such as the percentage losses in the platform and the trail system, broken grains, impurities, and the pods, which did not undergo threshing, were evaluated. The results obtained showed that the single-rotor harvester had a better energy efficiency, while the double-rotor harvester had a better operational performance. The double-rotor harvester was agronomically more efficient.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42799255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-23DOI: 10.1590/1413-7054202145002921
L. M. R. Rodrigues, S. Destéfano, L. Beriam, Mariana Ferreiro-Tonin, M. T. Braghini, Oliveiro Guerreiro Filho
ABSTRACT Seven wild accessions of Coffea arabica from Ethiopia prospected by FAO Coffee Mission 1964-1965 were investigated concerning the resistance to 18 Brazilian strains and two Kenyan strains of Pseudomonas syringae pv. garcae and four P. syringae pv. tabaci strains, causal agents of bacterial halo blight and bacterial leaf spot, respectively. The cultivars of C. arabica IPR 102, resistant to the diseases, and Mundo Novo IAC 376-4, susceptible, were used as experimental controls. Our results indicated that the Ethiopian accessions presented high levels of resistance to all Brazilian strains of P. syringae pv. garcae but were susceptible to infection caused by Kenyan strains, which causes different levels of severity in wild accessions and experimental controls. Ethiopian accessions were also considered resistant to the four P. syringae pv. tabaci strains, with low susceptibility observed, one point on the severity scale, in access E-268 in response to a strain of the bacterium.
摘要:研究了联合国粮农组织咖啡代表团1964-1965年从埃塞俄比亚选育的7个野生阿拉比卡咖啡品种对18株巴西菌株和2株肯尼亚菌株丁香假单胞菌的抗性。花园和四个紫丁香属pv。烟粉虱菌株分别为细菌性光晕疫病和细菌性叶斑病的致病因子。以抗病阿拉比卡品种IPR 102和易感品种Mundo Novo IAC 376-4为对照。结果表明，埃塞俄比亚种质对巴西产丁香假单胞菌均表现出较高的抗性。但是容易受到肯尼亚菌株引起的感染，这在野生品种和实验对照中造成不同程度的严重程度。埃塞俄比亚品种也被认为对4种紫丁香假单胞菌具有抗性。在E-268通道对一株细菌的反应中，观察到易受感染的烟粉虱菌株，在严重程度量表上为1分。
{"title":"Ethiopian coffee germplasm is a valuable resistance gene pool to brazilian Pseudomonas syringae PVS garcae and tabaci","authors":"L. M. R. Rodrigues, S. Destéfano, L. Beriam, Mariana Ferreiro-Tonin, M. T. Braghini, Oliveiro Guerreiro Filho","doi":"10.1590/1413-7054202145002921","DOIUrl":"https://doi.org/10.1590/1413-7054202145002921","url":null,"abstract":"ABSTRACT Seven wild accessions of Coffea arabica from Ethiopia prospected by FAO Coffee Mission 1964-1965 were investigated concerning the resistance to 18 Brazilian strains and two Kenyan strains of Pseudomonas syringae pv. garcae and four P. syringae pv. tabaci strains, causal agents of bacterial halo blight and bacterial leaf spot, respectively. The cultivars of C. arabica IPR 102, resistant to the diseases, and Mundo Novo IAC 376-4, susceptible, were used as experimental controls. Our results indicated that the Ethiopian accessions presented high levels of resistance to all Brazilian strains of P. syringae pv. garcae but were susceptible to infection caused by Kenyan strains, which causes different levels of severity in wild accessions and experimental controls. Ethiopian accessions were also considered resistant to the four P. syringae pv. tabaci strains, with low susceptibility observed, one point on the severity scale, in access E-268 in response to a strain of the bacterium.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67201639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-04DOI: 10.1590/1413-7054202145023920
Pietros André Balbino dos Santos, C. A. U. Monti, L. G. Carvalho, W. S. Lacerda, F. Schwerz
ABSTRACT Air temperature significantly affects the processes involving agricultural and human activities. The knowledge of the temperature of a given location is essential for agricultural planning. It also helps to make decisions regarding human activities. However, it is not always possible to determine this variable. It is necessary to make a precise estimate, using methods that are capable of detecting the existing variations. The aim of this study was to develop models of multiple linear regression (MLR), artificial neural network (ANN), and random forest (RF) to estimate the mean (Tmean), maximum (Tmax), and minimum (Tmin) monthly air temperatures as a function of geographic coordinates and altitude for different localities in Minas Gerais state, Brazil, with climatic classification Cwa or Cwb. The average monthly data (Tmean, Tmax, and Tmin), over a period of 30 years, were collected from 20 climatological stations. The MLR was able to estimate the Tmax with accuracy. However, the predictive capacity of estimating Tmean and Tmin was low. The algorithms RF and ANN were used to estimate Tmean, Tmax, and Tmin with high accuracy. The best results were obtained using the RF model.
{"title":"Air temperature estimation techniques in Minas Gerais state, Brazil, Cwa and Cwb climate regions according to the Köppen-Geiger climate classification system","authors":"Pietros André Balbino dos Santos, C. A. U. Monti, L. G. Carvalho, W. S. Lacerda, F. Schwerz","doi":"10.1590/1413-7054202145023920","DOIUrl":"https://doi.org/10.1590/1413-7054202145023920","url":null,"abstract":"ABSTRACT Air temperature significantly affects the processes involving agricultural and human activities. The knowledge of the temperature of a given location is essential for agricultural planning. It also helps to make decisions regarding human activities. However, it is not always possible to determine this variable. It is necessary to make a precise estimate, using methods that are capable of detecting the existing variations. The aim of this study was to develop models of multiple linear regression (MLR), artificial neural network (ANN), and random forest (RF) to estimate the mean (Tmean), maximum (Tmax), and minimum (Tmin) monthly air temperatures as a function of geographic coordinates and altitude for different localities in Minas Gerais state, Brazil, with climatic classification Cwa or Cwb. The average monthly data (Tmean, Tmax, and Tmin), over a period of 30 years, were collected from 20 climatological stations. The MLR was able to estimate the Tmax with accuracy. However, the predictive capacity of estimating Tmean and Tmin was low. The algorithms RF and ANN were used to estimate Tmean, Tmax, and Tmin with high accuracy. The best results were obtained using the RF model.","PeriodicalId":10188,"journal":{"name":"Ciencia E Agrotecnologia","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82515550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：