Revista de la Facultad de Ciencias Agrarias
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Incidence, prevalence and persistence of bovine venereal diseases in La Pampa (Argentina): estimations for the period 2007 - 2020
Get PDFThe venereal diseases Bovine Trichomoniasis (BT) and Bovine Genital Campylobacteriosis (BGC) cause economic losses in endemic areas, such as the province of La Pampa in Argentina, where bovine production is typically extensive. This study has used data compiled from 2007 to 2013 by the Official Program for the Control and Eradication (PCE) of venereal diseases, aiming to determine the prevalence, incidence and persistence of BT and BGC and to provide projections until 2020. Fourteen univariate models were used to adjust each time series. The prevalence and incidence of both diseases have significantly decreased during the studied period, while the persistence has remained constant. The prevalence of BT has diminished from 7.48% in 2007 to 3.03% in 2013, while the prevalence of BGC has diminished from 9.36% to 3.15%. The incidences have been reduced to an annual average of 0.60 for BT and 0.67 for BGC. Although the estimation models are not able to predict accurately the future epidemiologic rates of BT and BGC in La Pampa, projections show a significant decreasing trend of the prevalence and incidence of BT and BGC. The persistence of BGC is expected to remain close to the 2007-2013 average, while the persistence of BT did not adjust to any of the 14 models used. These results indicate that PCE has been effective to reduce the infection of disease-free herds. However, in order to reduce the ratio of persistent herds, other preventive and management measures should be considered.
Highlights
The venereal diseases Bovine Trichomoniasis (BT) and Bovine Genital Campylobacteriosis (BGC) cause economic losses.
Univariate analysis was an effective tool for modeling the historical and future prevalence, incidence and persistence of BT and BGC infections.
The prevalence and incidence of BT and BGC have significantly decreased during the studied period, while the persistence has remained constant.
The Official Program for the Control and Eradication (PCE) of venereal diseases, has been effective to reduce the infection of disease-free herds.The venereal diseases Bovine Trichomoniasis (BT) and Bovine Genital Campylobacteriosis (BGC) cause economic losses in endemic areas, such as the province of La Pampa in Argentina, where bovine production is typically extensive. This study has used data compiled from 2007 to 2013 by the Official Program for the Control and Eradication (PCE) of venereal diseases, aiming to determine the prevalence, incidence and persistence of BT and BGC and to provide projections until 2020. Fourteen univariate models were used to adjust each time series. The prevalence and incidence of both diseases have significantly decreased during the studied period, while the persistence has remained constant. The prevalence of BT has diminished from 7.48% in 2007 to 3.03% in 2013, while the prevalence of BGC has diminished from 9.36% to 3.15%. The incidences have been reduced to an annual average of 0.60 for BT and 0.67 for BGC. Although the estimation models are not able to predict accurately the future epidemiologic rates of BT and BGC in La Pampa, projections show a significant decreasing trend of the prevalence and incidence of BT and BGC. The persistence of BGC is expected to remain close to the 2007-2013 average, while the persistence of BT did not adjust to any of the 14 models used. These results indicate that PCE has been effective to reduce the infection of disease-free herds. However, in order to reduce the ratio of persistent herds, other preventive and management measures should be considered.
Highlights
The venereal diseases Bovine Trichomoniasis (BT) and Bovine Genital Campylobacteriosis (BGC) cause economic losses.
Univariate analysis was an effective tool for modeling the historical and future prevalence, incidence and persistence of BT and BGC infections.
The prevalence and incidence of BT and BGC have significantly decreased during the studied period, while the persistence has remained constant.
The Official Program for the Control and Eradication (PCE) of venereal diseases, has been effective to reduce the infection of disease-free herds
Effectivity and selectivity of herbicides applied in pre-emergence in the sesame (Sesamum indicum L.) crop
Get PDFWeed control in the sesame crop (Sesamum indicum L.) is a fundamental practice that ensures high grain yield. Choosing adequate control methods is a crucial step to reduce costs and reach success in weed management. Among these methods, application of chemicals shows high efficiency and low cost for farmers. However, the use of this method in sesame crops is limited because there is a restricted number of herbicides registered for pre- and post-emergence applications. Considering the importance of chemical methods for weed management, the objective of this research was to select herbicides to be applied in pre-emergence that could be used to control weeds in the sesame crop. Two experiments were carried out, one to determine the efficiency and another to determine the selectivity of herbicides applied in pre emergence. The experiments were performed in a randomized complete block design (CBD) with four replicates. The treatments consisted of seven herbicides, a mixture of herbicides applied in pre-emergence, and two control treatments, one weed-free and one with weeds. Diuron and flumioxazin were found to be selective for pre-emergence. Metribuzin exhibited high toxicity to sesame, but it was effective to control several weed species, and metolachlor did not provoke high phytotoxicity in sesame, but reduced yield.
Highlights:
The control of weeds in the sesame crop is a fundamental practice for the productivity of this oilseed.
The chemical method applied is the most used due to its high efficiency and low cost.
Few herbicides applied in preemergence are registered for sesame cultivation.
The selectivity and efficiency of 8 herbicides applied pre-emergence in sesame was studied.
The herbicides Diuron and flumioxazin were selective for the cultivation of sesame and efficient in the control of weeds.Weed control in the sesame crop (Sesamum indicum L.) is a fundamental practice that ensures high grain yield. Choosing adequate control methods is a crucial step to reduce costs and reach success in weed management. Among these methods, application of chemicals shows high efficiency and low cost for farmers. However, the use of this method in sesame crops is limited because there is a restricted number of herbicides registered for pre- and post-emergence applications. Considering the importance of chemical methods for weed management, the objective of this research was to select herbicides to be applied in pre-emergence that could be used to control weeds in the sesame crop. Two experiments were carried out, one to determine the efficiency and another to determine the selectivity of herbicides applied in pre emergence. The experiments were performed in a randomized complete block design (CBD) with four replicates. The treatments consisted of seven herbicides, a mixture of herbicides applied in pre-emergence, and two control treatments, one weed-free and one with weeds. Diuron and flumioxazin were found to be selective for pre-emergence. Metribuzin exhibited high toxicity to sesame, but it was effective to control several weed species, and metolachlor did not provoke high phytotoxicity in sesame, but reduced yield.
Highlights:
The control of weeds in the sesame crop is a fundamental practice for the productivity of this oilseed.
The chemical method applied is the most used due to its high efficiency and low cost.
Few herbicides applied in preemergence are registered for sesame cultivation.
The selectivity and efficiency of 8 herbicides applied pre-emergence in sesame was studied.
The herbicides Diuron and flumioxazin were selective for the cultivation of sesame and efficient in the control of weeds
Corn (Zea mais L.) sowing quality in the province of Corrientes, Argentina
Get PDFIn three departments of the Corrientes province, the performance of 6 seeders was evaluated during corn sowing at three different speeds for each machine. A randomized complete block design was used with nested treatments arrangement. A seeder factor (6 types), a speed factor (3 levels) and three blocks determined a total of 54 experimental units. As for the speed factor, the first level corresponds to speed 2 (Sp 2) which the operator regularly uses. The second level and the third level correspond to a lower speed (Sp 1) and a higher speed (Sp 3) respectively which were used for this study. The equidistance between seeds and sowing depth were analysed as the response variable. Conclusions: 1) Four of the six seeders studied at three chosen speeds showed no differences regarding seed deposition. This was observed considering significant differences between sowing depth and seed spacing in a given line. 2) The two methodologies used to evaluate sowing efficiency, i.e. the coefficient of variation (CV) and the ISO 7256-1 standard, showed differences in evaluation. The second technique was more accurate since no differences between treatments were found with the CV. 3) According to these results, it is possible to conclude that the corn sowing quality in the Corrientes province is acceptable at the sowing speeds used by the contractors.
Highlights
The corn crop sowing quality process carried out by the contractors in the Corrientes province is within the standards set by international regulations.
Sowing quality remained at acceptable values between speeds of 5,7 and 10,5 km h-1.
The international standard ISO 7256-1 to measure sowing quality presented greater requirements with respect to the local methodology generally used in Argentina based on the coefficient of variation.In three departments of the Corrientes province, the performance of 6 seeders was evaluated during corn sowing at three different speeds for each machine. A randomized complete block design was used with nested treatments arrangement. A seeder factor (6 types), a speed factor (3 levels) and three blocks determined a total of 54 experimental units. As for the speed factor, the first level corresponds to speed 2 (Sp 2) which the operator regularly uses. The second level and the third level correspond to a lower speed (Sp 1) and a higher speed (Sp 3) respectively which were used for this study. The equidistance between seeds and sowing depth were analysed as the response variable. Conclusions: 1) Four of the six seeders studied at three chosen speeds showed no differences regarding seed deposition. This was observed considering significant differences between sowing depth and seed spacing in a given line. 2) The two methodologies used to evaluate sowing efficiency, i.e. the coefficient of variation (CV) and the ISO 7256-1 standard, showed differences in evaluation. The second technique was more accurate since no differences between treatments were found with the CV. 3) According to these results, it is possible to conclude that the corn sowing quality in the Corrientes province is acceptable at the sowing speeds used by the contractors.
Highlights
The corn crop sowing quality process carried out by the contractors in the Corrientes province is within the standards set by international regulations.
Sowing quality remained at acceptable values between speeds of 5,7 and 10,5 km h-1.
The international standard ISO 7256-1 to measure sowing quality presented greater requirements with respect to the local methodology generally used in Argentina based on the coefficient of variation
Spatio and temporal spread of Plum pox virus infecting European plum (Prunus domestica L. cv. D'agen) orchard in Mendoza, Argentina
Get PDFSharka, caused by Plum pox virus (PPV), is considered one of the most serious viral diseases of stone fruits worldwide due to the great yield losses in orchards. In Rama Caída, Mendoza, a 5-year study (2007-2011) was conducted in a European plum cv D’agen orchard using samples from leaves and DAS-ELISA assay against PPV in order to determine incidence over time and spatial spread. Incidence significantly increased between 2007 and 2009, while for the next two years the increase was not statistically significant. Spatial point pattern of PPV at the plot was characterized by the occurrence of some heterogeneous clusters of infected trees located up to 65 m in the west-east direction of the rows over the five years. Point pattern and correlation type-approaches were undertaken using joint-count and Ripley's K function and showed that the detectedinfected plants had a disease aggregation pattern both in west-east and south-north directions, as well as within and between rows across the plot. This short-distance local dispersion would be associated with diverse factors, such as vector aphids, that were not evaluated in this study. Hence, this work can serve as a basis for further studies of sharka dispersion in Cuyo region.
Highlights
Plum pox virus (PPV) positive trees were detected by DAS-ELISA showing an increasing number of diseased plants overtime in a European plum cv D’agen plot in Rama Caída, Mendoza, Argentina during five years.
The incidence of overtime was higher at the beginning of the study instead of the following years, indicating that the PPV epidemic was at a very early stage.
The spatial point pattern of PPV at the plot was characterized by some heterogeneous clusters of infected trees observed from initial focus (within the row) up to 65 m in the west-east direction of the rows.
Heterogeneous aggregated spatial associations of PPV occurred close in space and time, which was confirmed by autocorrelation spatial analysis with Ripley's K function and Join-count.
An aggregated point pattern of PPV had a positive correlation between the infected tree and the distance between each one showing a disease aggregation in both directions W-E and S-N, across the plot.Sharka, caused by Plum pox virus (PPV), is considered one of the most serious viral diseases of stone fruits worldwide due to the great yield losses in orchards. In Rama Caída, Mendoza, a 5-year study (2007-2011) was conducted in a European plum cv D’agen orchard using samples from leaves and DAS-ELISA assay against PPV in order to determine incidence over time and spatial spread. Incidence significantly increased between 2007 and 2009, while for the next two years the increase was not statistically significant. Spatial point pattern of PPV at the plot was characterized by the occurrence of some heterogeneous clusters of infected trees located up to 65 m in the west-east direction of the rows over the five years. Point pattern and correlation type-approaches were undertaken using joint-count and Ripley's K function and showed that the detectedinfected plants had a disease aggregation pattern both in west-east and south-north directions, as well as within and between rows across the plot. This short-distance local dispersion would be associated with diverse factors, such as vector aphids, that were not evaluated in this study. Hence, this work can serve as a basis for further studies of sharka dispersion in Cuyo region.
Highlights
Plum pox virus (PPV) positive trees were detected by DAS-ELISA showing an increasing number of diseased plants overtime in a European plum cv D’agen plot in Rama Caída, Mendoza, Argentina during five years.
The incidence of overtime was higher at the beginning of the study instead of the following years, indicating that the PPV epidemic was at a very early stage.
The spatial point pattern of PPV at the plot was characterized by some heterogeneous clusters of infected trees observed from initial focus (within the row) up to 65 m in the west-east direction of the rows.
Heterogeneous aggregated spatial associations of PPV occurred close in space and time, which was confirmed by autocorrelation spatial analysis with Ripley's K function and Join-count.
An aggregated point pattern of PPV had a positive correlation between the infected tree and the distance between each one showing a disease aggregation in both directions W-E and S-N, across the plot
Protein content and quality of seeds in central mexican maize (Zea mays) accessions
Get PDFMexico is the center of the origin, domestication and diversity of maize. This cereal is the main constituent of the Mexican diet, especially in low-income families. In this research, 10 maize accessions derived from a large landrace collection, with the 'INIFAP-QPM' accession and a 'regional landrace' as controls, were studied to identify the accessions with the best biochemical and physiological characteristics showing good adaptation to 'El Bajío' (regional center in Mexico) conditions. The accessions were statistically superior to the two controls in the germination and accelerated aging tests. In the assessment of variable plumule length, variability was observed among the accessions, but the controls showed the lowest values. Protein contents in different fractions (albumins, globulins, prolamins and glutelins) showed variability as did oil and fiber contents. The 'HRH2015' accession showed high contents of albumins and globulins and low contents of prolamins and glutelins. The 'regional landrace' accession exhibited the highest contents of glutelins and prolamins but the lowests content of globulins and albumins. The total percentage of proteins showed variability among the accessions, but the values were within those reported in the literature. The 'RQ2015' accession presented the highest oil content (5.25%). The electrophoretic patterns of prolamins were obtained, and some differences were observed between them. The 'regional landrace' presented the lowest protein content, which was significantly different from those of the other accessions evaluated. This research demonstrates biochemical, germination and vigor variability among the studied maize accessions.
Highlights
The protein fraction content showed highly significant differences between the accessions, the accession 'HRH2015' presented the highest total soluble protein content.
The 'HRH2015' accession contained high percentages of the albumin, globulin and prolamin fractions, but a lower percentage of the glutelin fraction, which is a suitable material for breeding.
The accessions 'A2015', 'POL2015' and 'FVR12015' were superior in seed quality, these accessions could be used in a future breeding program.Mexico is the center of the origin, domestication and diversity of maize. This cereal is the main constituent of the Mexican diet, especially in low-income families. In this research, 10 maize accessions derived from a large landrace collection, with the 'INIFAP-QPM' accession and a 'regional landrace' as controls, were studied to identify the accessions with the best biochemical and physiological characteristics showing good adaptation to 'El Bajío' (regional center in Mexico) conditions. The accessions were statistically superior to the two controls in the germination and accelerated aging tests. In the assessment of variable plumule length, variability was observed among the accessions, but the controls showed the lowest values. Protein contents in different fractions (albumins, globulins, prolamins and glutelins) showed variability as did oil and fiber contents. The 'HRH2015' accession showed high contents of albumins and globulins and low contents of prolamins and glutelins. The 'regional landrace' accession exhibited the highest contents of glutelins and prolamins but the lowests content of globulins and albumins. The total percentage of proteins showed variability among the accessions, but the values were within those reported in the literature. The 'RQ2015' accession presented the highest oil content (5.25%). The electrophoretic patterns of prolamins were obtained, and some differences were observed between them. The 'regional landrace' presented the lowest protein content, which was significantly different from those of the other accessions evaluated. This research demonstrates biochemical, germination and vigor variability among the studied maize accessions.
Highlights
The protein fraction content showed highly significant differences between the accessions, the accession 'HRH2015' presented the highest total soluble protein content.
The 'HRH2015' accession contained high percentages of the albumin, globulin and prolamin fractions, but a lower percentage of the glutelin fraction, which is a suitable material for breeding.
The accessions 'A2015', 'POL2015' and 'FVR12015' were superior in seed quality, these accessions could be used in a future breeding program
Milk production in dairy cows supplemented with herbal choline and methionine
Get PDFThe objective of this study was to evaluate the supplementation of herbal choline and methionine to dairy cows on milk production and milk composition during 60 days of lactation, while also identifying the volatile compounds of the herbal methionine and choline. Fourteen compounds were identified for herbal methionine and fifteen in herbal choline including aromas, alcohols, aldehydes and phenolics, some with nutraceutical properties. Twenty-multiparous Holstein cows (body condition score, BCS = 3.1 ± 0.15; mean ± SE) were fed a basal diet (16.3% CP, 1.6% DP and 1.71. Mcal/kg ME). Seven days after calving, cows were randomly assigned to treatments, which consisted of control basal diet or an oral dose of herbal choline (15 g/d) plus herbal methionine (10 g/d). The experiment lasted 60 days with measurements of milk production and composition every 7 days. Supplementation with herbal choline plus herbal methionine improved (P <0.05) milk production (32.96 vs. 34.03 kg/d) and 4% FCM (28.23 vs. 29.91 kg/d). Protein content decreased (P <0.05) on supplemented cows (29.9 vs. 31.7 g/kg). However, no effects on the remaining composition (fat, lactose, total solids and non-fatty solids) was found. Milk production can be improved by supplementing cows with the evaluated herbal sources of choline and methionine.The objective of this study was to evaluate the supplementation of herbal choline and methionine to dairy cows on milk production and milk composition during 60 days of lactation, while also identifying the volatile compounds of the herbal methionine and choline. Fourteen compounds were identified for herbal methionine and fifteen in herbal choline including aromas, alcohols, aldehydes and phenolics, some with nutraceutical properties. Twenty-multiparous Holstein cows (body condition score, BCS = 3.1 ± 0.15; mean ± SE) were fed a basal diet (16.3% CP, 1.6% DP and 1.71. Mcal/kg ME). Seven days after calving, cows were randomly assigned to treatments, which consisted of control basal diet or an oral dose of herbal choline (15 g/d) plus herbal methionine (10 g/d). The experiment lasted 60 days with measurements of milk production and composition every 7 days. Supplementation with herbal choline plus herbal methionine improved (P <0.05) milk production (32.96 vs. 34.03 kg/d) and 4% FCM (28.23 vs. 29.91 kg/d). Protein content decreased (P <0.05) on supplemented cows (29.9 vs. 31.7 g/kg). However, no effects on the remaining composition (fat, lactose, total solids and non-fatty solids) was found. Milk production can be improved by supplementing cows with the evaluated herbal sources of choline and methionine
Water and radiation productivity in different cropping sequences in the north center of Santa Fe
Get PDFDry matter and grain productions depend on the ability of crops to capture resources. Productivity of resourses is defined based on the amount of grain or dry matter produced per unit of available resource (solar radiation or rainfall) during the year. Our main objective was to evaluate the effect of different crop sequences on the productivity of water (WP) and radiation (RP) resources for grain production and total dry matter (DM). The trial was carried out during 2014/15 and 2015/16. Nine sequences were established, including different cultures and fertilization doses with a 25, 50 or 75 % -variable-participation of grasses.
Increases of the order of 125 and 125 % were determined in WP, and of 141 and 142 % for RP for grain and DM respectively, in the sequence b/fc-w/s respect v/s-w/s (b: barley; w: wheat; s: soybean; v: vicia; fc: fertilized corn). The results showed that the sequences of crops that included higher percentage of grasses and the adequate fertilization, increased water and radiation efficiency and productivity, achieving a greatercontribution of carbon from crop residues.
Highlights
The sequences of crops that included a greater percentage of grasses increased efficiency and productivity in the use of water and radiation.
The rotations with 75% of grasses and high fertilization achieved the highest productions of dry matter and contributions of C of crop residues.
Water and radiation use efficiency in currently most common sequence for the Argentine Pampas region are lower than crop sequences obtainedin optimized sequence in this work, and can be improved.Dry matter and grain productions depend on the ability of crops to capture resources. Productivity of resourses is defined based on the amount of grain or dry matter produced per unit of available resource (solar radiation or rainfall) during the year. Our main objective was to evaluate the effect of different crop sequences on the productivity of water (WP) and radiation (RP) resources for grain production and total dry matter (DM). The trial was carried out during 2014/15 and 2015/16. Nine sequences were established, including different cultures and fertilization doses with a 25, 50 or 75 % -variable-participation of grasses.
Increases of the order of 125 and 125 % were determined in WP, and of 141 and 142 % for RP for grain and DM respectively, in the sequence b/fc-w/s respect v/s-w/s (b: barley; w: wheat; s: soybean; v: vicia; fc: fertilized corn). The results showed that the sequences of crops that included higher percentage of grasses and the adequate fertilization, increased water and radiation efficiency and productivity, achieving a greatercontribution of carbon from crop residues.
Highlights
The sequences of crops that included a greater percentage of grasses increased efficiency and productivity in the use of water and radiation.
The rotations with 75% of grasses and high fertilization achieved the highest productions of dry matter and contributions of C of crop residues.
Water and radiation use efficiency in currently most common sequence for the Argentine Pampas region are lower than crop sequences obtainedin optimized sequence in this work, and can be improved
Olive oil and the millennial generation in Chile. What do these consumers consider when buying this product?
Get PDFThis study aimed to identify the attributes influencing the purchase decision process of the olive oil consumer belonging to "Millennials" in the Metropolitan Region, Chile. The method includes data collection from 408 people and a combination of factorial and cluster analysis. The results identified two segments in the millennial consumers. In the purchasing, one of the consumer groups, with 150 people, attached importance to product information and origin, as well as oil category, colour, and acidity. The other group with 258 people rejected a large part of the attributes, except for that related to electronic commerce. These results suggest that the search for attractive attributes in a broad sense is relevant and should be considered in the development of commercial strategies for the segment that positively values all attributes. However, for that segment rejecting intrinsic attributes, it would be advisable to deepen on aspects related to technology and social network.
Highlights
Young consumers of olive oil in Chile.
Signs for product development and marketing channels in the millennial generation.
Important receptivity of the electronic channel for the marketing of olive oil.This study aimed to identify the attributes influencing the purchase decision process of the olive oil consumer belonging to "Millennials" in the Metropolitan Region, Chile. The method includes data collection from 408 people and a combination of factorial and cluster analysis. The results identified two segments in the millennial consumers. In the purchasing, one of the consumer groups, with 150 people, attached importance to product information and origin, as well as oil category, colour, and acidity. The other group with 258 people rejected a large part of the attributes, except for that related to electronic commerce. These results suggest that the search for attractive attributes in a broad sense is relevant and should be considered in the development of commercial strategies for the segment that positively values all attributes. However, for that segment rejecting intrinsic attributes, it would be advisable to deepen on aspects related to technology and social network.
Highlights
Young consumers of olive oil in Chile.
Signs for product development and marketing channels in the millennial generation.
Important receptivity of the electronic channel for the marketing of olive oil
Effects of calcium silicate on the protection of Brachiaria seeds against Sclerotium rolfsii: Protection of Brachiaria seeds against Sclerotium rolfsii Sacc.
No full textSclerotium rolfsii a fungus widespread in tropical and subtropical regions, is a phytopathogen that affects a large number of cultivated and wild plants"”e.g. Brachiaria species"”, causing damping-off. Current disease control strategies include chemical treatment of seeds, genetic resistance and crop rotation. Compared to synthetic agrochemicals, silicon may act as an element inducing plant resistance. This study examined the efficiency of calcium silicate in the coating of Brachiaria seeds on the incidence of the disease during plant germination and establishment. The experiment consisted of six Brachiaria brizantha seed-coating treatments involving different proportions of calcium silicate and sand, plus two controls. The fungus was inoculated at three different times in relation to seed sowing, namely, inoculation along with sowing (IN0); inoculation 10 days after sowing (IN10); inoculation 20 days after sowing (IN20); and no inoculation (control). Radicle emergence, germination, abnormal seedlings, damped-off seedlings and dead seeds were evaluated. There was an increase in the germination rate of B. brizantha cv. MG5 seeds coated with calcium silicate, which showed a protective effect against the incidence of S. rolfsii, directly reflecting in a lower of percentage of damping-off.
Highlights
According to the results obtained, it is convenient to use seeds coated with calcium silicate increases and inoculated with rolfsii.
Seed coating with calcium silicate decreased damping-off in plants.
Silicon can contribute to increase crop yield and disease resistance, given the benefits demonstrated in the current experiment.Sclerotium rolfsii a fungus widespread in tropical and subtropical regions, is a phytopathogen that affects a large number of cultivated and wild plants"”e.g. Brachiaria species"”, causing damping-off. Current disease control strategies include chemical treatment of seeds, genetic resistance and crop rotation. Compared to synthetic agrochemicals, silicon may act as an element inducing plant resistance. This study examined the efficiency of calcium silicate in the coating of Brachiaria seeds on the incidence of the disease during plant germination and establishment. The experiment consisted of six Brachiaria brizantha seed-coating treatments involving different proportions of calcium silicate and sand, plus two controls. The fungus was inoculated at three different times in relation to seed sowing, namely, inoculation along with sowing (IN0); inoculation 10 days after sowing (IN10); inoculation 20 days after sowing (IN20); and no inoculation (control). Radicle emergence, germination, abnormal seedlings, damped-off seedlings and dead seeds were evaluated. There was an increase in the germination rate of B. brizantha cv. MG5 seeds coated with calcium silicate, which showed a protective effect against the incidence of S. rolfsii, directly reflecting in a lower of percentage of damping-off.
Highlights
According to the results obtained, it is convenient to use seeds coated with calcium silicate increases and inoculated with rolfsii.
Seed coating with calcium silicate decreased damping-off in plants.
Silicon can contribute to increase crop yield and disease resistance, given the benefits demonstrated in the current experiment
Fruit peels as sources of bioactive compounds with antioxidant and antimicrobial properties
Get PDFRecently, a major interest in searching for phytochemicals with nutritional and pharmaceutical purposes has arisen. In this regard, it is known that polyphenols present antioxidant properties as well as an inhibitory effect against some kinds of microorganisms. The aim of this study was to obtain aqueous-ethanolic extracts from peels of avocado, cocoa bean, coconut and cactus pear by ultrasound-assisted extraction. The extracts were characterized in terms of phenolics (Folin-Ciocalteu reagent), antioxidant potential (ferric reducing/antioxidant power assay), radical-scavenging ability (2,2-diphenyl-2-picrylhydrazyl free radical assay), and antimicrobial activity against Staphylococcus aureus, Shigella dysenteriae and Candida albicans (disk diffusion test). The results revealed that the avocado peel extract had the highest phenol content (36.5 mg EAG g-1 dry weight), the highest antioxidant activity (141.2 mME Trolox g-1 dry weight) and the lowest IC50 value (59 ppm). Furthermore, avocado and coconut peels demonstrated an inhibitory effect against the tested microorganisms.
Highlights
Bioactive compounds from fruit by-products were obtained by ultrasound-assisted extraction.
A positive correlation between phenolics and antioxidant activity was observed.
Extracts with higher antioxidant activity were more active against the tested microorganisms.
Fruit by-products could represent an important source of compounds with antioxidant and antimicrobial properties.Recently, a major interest in searching for phytochemicals with nutritional and pharmaceutical purposes has arisen. In this regard, it is known that polyphenols present antioxidant properties as well as an inhibitory effect against some kinds of microorganisms. The aim of this study was to obtain aqueous-ethanolic extracts from peels of avocado, cocoa bean, coconut and cactus pear by ultrasound-assisted extraction. The extracts were characterized in terms of phenolics (Folin-Ciocalteu reagent), antioxidant potential (ferric reducing/antioxidant power assay), radical-scavenging ability (2,2-diphenyl-2-picrylhydrazyl free radical assay), and antimicrobial activity against Staphylococcus aureus, Shigella dysenteriae and Candida albicans (disk diffusion test). The results revealed that the avocado peel extract had the highest phenol content (36.5 mg EAG g-1 dry weight), the highest antioxidant activity (141.2 mME Trolox g-1 dry weight) and the lowest IC50 value (59 ppm). Furthermore, avocado and coconut peels demonstrated an inhibitory effect against the tested microorganisms.
Highlights
Bioactive compounds from fruit by-products were obtained by ultrasound-assisted extraction.
A positive correlation between phenolics and antioxidant activity was observed.
Extracts with higher antioxidant activity were more active against the tested microorganisms.
Fruit by-products could represent an important source of compounds with antioxidant and antimicrobial properties