Revista de la Facultad de Ciencias Agrarias
Not a member yet
621 research outputs found
Sort by
Effects of different energy source diets, as corn substitutes, on carcass characteristics and meat quality of feedlot lambs
Get PDFThis study evaluated the effects of different energy sources, as corn substitutes, on the carcass characteristics and meat quality of lambs. Twenty-four intact ram lambs were identified, weighed, and assigned to one of four dietary treatments: corn, citrus pulp, rice bran, and soybean hulls. The ram lambs were confined in feedlots, and when they reached 30 kg of live weight, they were slaughtered. A completelyrandomized design with different replicates was used for the analysis, along with the Tukey-5% test. For hot and cold carcass weight, rice bran produced lower values than the other dietary treatments. For the red color content of the meat, citrus pulp presented superior values when compared to corn, whereas meat and fat color, loin eye area, and objective tenderness did not differ between treatments. Different energetic sources used to replace corn in ram lambs finishing diets did not affect the proximate composition and quality of the meat.
Highlights:
• Addition of rice bran to the lambs' diet resulted in lower hot and cold carcass weight.• Animals fed soybean hulls presented the highest carcass compactness index values.• Rice bran extended the feedlot period of lambs in 59.33 days, been longer than the others energies sources.• Corn, rice bran, citrus pulp and soybean hulls did not change the quality of meat but the inclusion of rice bran should be carefully evaluated.This study evaluated the effects of different energy sources, as corn substitutes, on the carcass characteristics and meat quality of lambs. Twenty-four intact ram lambs were identified, weighed, and assigned to one of four dietary treatments: corn, citrus pulp, rice bran, and soybean hulls. The ram lambs were confined in feedlots, and when they reached 30 kg of live weight, they were slaughtered. A completelyrandomized design with different replicates was used for the analysis, along with the Tukey-5% test. For hot and cold carcass weight, rice bran produced lower values than the other dietary treatments. For the red color content of the meat, citrus pulp presented superior values when compared to corn, whereas meat and fat color, loin eye area, and objective tenderness did not differ between treatments. Different energetic sources used to replace corn in ram lambs finishing diets did not affect the proximate composition and quality of the meat.
Highlights:
• Addition of rice bran to the lambs' diet resulted in lower hot and cold carcass weight.• Animals fed soybean hulls presented the highest carcass compactness index values.• Rice bran extended the feedlot period of lambs in 59.33 days, been longer than the others energies sources.• Corn, rice bran, citrus pulp and soybean hulls did not change the quality of meat but the inclusion of rice bran should be carefully evaluated
Social impact analysis of cultural tourism in rural areas of Tlaxcala, Mexico
Get PDFAlternative tourism, specifically cultural tourism, has gained worldwide importance. This is reflected in the growing number of people preferring this type of leisure activity. However, and even though archaeological and religious contexts represent hubs of attraction for pilgrims and tourists, their development seems to generate social issues. The objective of this research is to analyse the social impact of cultural tourism, from the perspective of tradesmen living in the rural municipality of Tlaxcala, Mexico. Information was collected by surveys. Sample size was calculated using the non-probabilistic method (snowball), and 54 tradesmen owning establishments near tourist attractions, were interviewed. Results evidenced that tradesmen do perceive social problems including traffic congestion, increasing living costs, pollution, street vendors, and augmented competition between businesses. However, they appreciate the benefits of providing tourists with low-cost catering services, considering tourism to be positive or very positive. The conclusion is that economic benefits outweigh the social impacts generated by tourism.
Highlights:
The influx of pilgrims and tourists is generating some social problems in the receiving rural spaces.
Tourism service providers derive little benefit due to the low-cost services in accommodation and meal offer to tourists.
Social problems are increasing (road traffic, higher cost of living, pollution, street vendors) and greater competition between businesses.
Tourist activity is considered good or very good since it contributes to local development.Alternative tourism, specifically cultural tourism, has gained worldwide importance. This is reflected in the growing number of people preferring this type of leisure activity. However, and even though archaeological and religious contexts represent hubs of attraction for pilgrims and tourists, their development seems to generate social issues. The objective of this research is to analyse the social impact of cultural tourism, from the perspective of tradesmen living in the rural municipality of Tlaxcala, Mexico. Information was collected by surveys. Sample size was calculated using the non-probabilistic method (snowball), and 54 tradesmen owning establishments near tourist attractions, were interviewed. Results evidenced that tradesmen do perceive social problems including traffic congestion, increasing living costs, pollution, street vendors, and augmented competition between businesses. However, they appreciate the benefits of providing tourists with low-cost catering services, considering tourism to be positive or very positive. The conclusion is that economic benefits outweigh the social impacts generated by tourism.
Highlights:
The influx of pilgrims and tourists is generating some social problems in the receiving rural spaces.
Tourism service providers derive little benefit due to the low-cost services in accommodation and meal offer to tourists.
Social problems are increasing (road traffic, higher cost of living, pollution, street vendors) and greater competition between businesses.
Tourist activity is considered good or very good since it contributes to local development
Effect of blue, green or red LED light on the functional quality of spinach (Spinacia oleracea L.)
No full textThe present study employed white (W), blue (B: 468 nm), red (R: 629 nm) and green (G: 524 nm) monochromatic LED lights for 26 days, from 11:00 to 18:00 (7 h per day), with a average of photosynthetic photon flux density (PPFD) of 26.00 m-2 s-1 on two baby leaves of spinach (Spinacia oleracea L.) cultivars (Falcon F1 and Viroflay) grown in a hydroponic system. Regardless of the cultivar, the fresh and dry weights were positively influenced when the plants were irradiated by R-light in comparison to W-light. Independent of the cultivar, the leaves treated with B-light reached a significantly higher phenolic compound concentration than plants irradiated with W-light. With respect to antioxidant capacity, plants treated with B-light showed a significantly higher antioxidant capacity than those treated with W-light. According to the results, the use of LED lights is a promising technique for the production of antioxidant compound-enriched vegetables.
Highlights
- The fresh and dry weights were positively influenced when baby leaves spinach were irradiated by red LED light.
- Baby leaves spinach treated with blue LED light reached a significantly higher phenolic compound concentration and antioxidant capacity.
- The green LED light increased total phenolic compound concentration in baby leaves spinach.The present study employed white (W), blue (B: 468 nm), red (R: 629 nm) and green (G: 524 nm) monochromatic LED lights for 26 days, from 11:00 to 18:00 (7 h per day), with a average of photosynthetic photon flux density (PPFD) of 26.00 m-2 s-1 on two baby leaves of spinach (Spinacia oleracea L.) cultivars (Falcon F1 and Viroflay) grown in a hydroponic system. Regardless of the cultivar, the fresh and dry weights were positively influenced when the plants were irradiated by R-light in comparison to W-light. Independent of the cultivar, the leaves treated with B-light reached a significantly higher phenolic compound concentration than plants irradiated with W-light. With respect to antioxidant capacity, plants treated with B-light showed a significantly higher antioxidant capacity than those treated with W-light. According to the results, the use of LED lights is a promising technique for the production of antioxidant compound-enriched vegetables.
Highlights
- The fresh and dry weights were positively influenced when baby leaves spinach were irradiated by red LED light.
- Baby leaves spinach treated with blue LED light reached a significantly higher phenolic compound concentration and antioxidant capacity.
- The green LED light increased total phenolic compound concentration in baby leaves spinach
Implantation of corporate social responsibility measures in the horticulture in Mexico and Spain
Get PDFThis work presents the results of a survey, following the Delphi methodology, to experts from the horticultural sector of Mexico and Spain. Interactions with experts have made it possible to identify relevant aspects where the level of consensus is high about the proliferation of Corporate Social Responsibility (CSR) initiatives in the export sector of both countries, standing out: the horticultural sector's leadership in the implementation of standards, which responds to the demand for destination supermarkets in the US and Europe, which despite their particularities, have similar dynamics. Not implementing is considered a risk factor; the implementations are positive actions, which enhance the reputation of companies. Agricultural companies that have a lack of business culture, ignorance, and high administrative burden limit their development, especially among smaller production companies. The greatest progress has been made in the area of labor and environmental practices, areas where consumer concern is growing. Despite CRS initiatives are not providing an immediate benefit to companies, strategic spending is valued. The research is completed with a SWOT analysis (Weaknesses, Threats, Strengths and Opportunities), providing a valuable ranking of great interest for the design of competitive improvements.
Highlights
Corporate Social Responsibility (CRS) measures in the horticultural activity are driven mainly for the Supermarkets Chains. There are other factors to implement it: gain competitive advantage, improve the reputation of the sector, stay in the market.
The Delphi Method is a useful instrument to identify advantages, limitations, and barriers to adopt food safety and Social Responsibility Standards in the global value chain in the agricultural sector.
The horticultural activity is adopting several CRS standards in order to stay in the market such as: GRASP, FAIR TRADE, SEDEX, SA 8000.
The Delphi Panel considers that the CRS standards and measures implemented improve the labor, environmental and human rights in the horticultural activity in Mexico and Spain.This work presents the results of a survey, following the Delphi methodology, to experts from the horticultural sector of Mexico and Spain. Interactions with experts have made it possible to identify relevant aspects where the level of consensus is high about the proliferation of Corporate Social Responsibility (CSR) initiatives in the export sector of both countries, standing out: the horticultural sector's leadership in the implementation of standards, which responds to the demand for destination supermarkets in the US and Europe, which despite their particularities, have similar dynamics. Not implementing is considered a risk factor; the implementations are positive actions, which enhance the reputation of companies. Agricultural companies that have a lack of business culture, ignorance, and high administrative burden limit their development, especially among smaller production companies. The greatest progress has been made in the area of labor and environmental practices, areas where consumer concern is growing. Despite CRS initiatives are not providing an immediate benefit to companies, strategic spending is valued. The research is completed with a SWOT analysis (Weaknesses, Threats, Strengths and Opportunities), providing a valuable ranking of great interest for the design of competitive improvements.
Highlights
Corporate Social Responsibility (CRS) measures in the horticultural activity are driven mainly for the Supermarkets Chains. There are other factors to implement it: gain competitive advantage, improve the reputation of the sector, stay in the market.
The Delphi Method is a useful instrument to identify advantages, limitations, and barriers to adopt food safety and Social Responsibility Standards in the global value chain in the agricultural sector.
The horticultural activity is adopting several CRS standards in order to stay in the market such as: GRASP, FAIR TRADE, SEDEX, SA 8000.
The Delphi Panel considers that the CRS standards and measures implemented improve the labor, environmental and human rights in the horticultural activity in Mexico and Spain
CO2 emission allowances and their interacion with economic and energy factors in the European Union
Get PDFAnalysis of emission allowances prices has important environmental and political connotations. This article aimed to identifying the possible variables that may influence their behaviour and studied their relationship with fundamental factors: energy (Brent petroleum, Gas, Coal) and economy (Industrial Production Index, Baltic Dry Index, Purchasing Managers Index). With the objective of analyzing possible mutual interactions, Multivariate VAR or Error Correction Models (VECM), were applied. The information analysed derived from different sources (World Bank, Sendeco2 and various financial websites). The results obtained showed, not only the influence of past prices on the emission allowances actual price, but also the interaction with energetic and economic variables.
Highlights
Estimation of time series interrelations through VAR models.
There is relationship of the emission allowances price with their past values.
The energy variables are factors important to also explain the behavior of the emission allowances price.
The economic variables are hardly significant except for the Dry Baltic Index.Analysis of emission allowances prices has important environmental and political connotations. This article aimed to identifying the possible variables that may influence their behaviour and studied their relationship with fundamental factors: energy (Brent petroleum, Gas, Coal) and economy (Industrial Production Index, Baltic Dry Index, Purchasing Managers Index). With the objective of analyzing possible mutual interactions, Multivariate VAR or Error Correction Models (VECM), were applied. The information analysed derived from different sources (World Bank, Sendeco2 and various financial websites). The results obtained showed, not only the influence of past prices on the emission allowances actual price, but also the interaction with energetic and economic variables.
Highlights
Estimation of time series interrelations through VAR models.
There is relationship of the emission allowances price with their past values.
The energy variables are factors important to also explain the behavior of the emission allowances price.
The economic variables are hardly significant except for the Dry Baltic Index
Implementation of iceplant production under semi-controlled conditions
No full textMesembryanthemum crystallinum is considered a drought and saline stress-tolerant plant with many biological activities that has been revalued as cool flavouring plant. The objective of this work was to assess optimum mode of cultivation of M. crystallinum to produce edible parts under greenhouse conditions. Therefore, three soilless media were evaluated: peat, vermiculite and hydroponic culture. Pot culture in peat did not result to be a good substrate for iceplant, with little biomass production. However, vermiculite and hydroponics allowed optimum growth of M. crystallinum, with a significantly greater yield in plants grown in vermiculite irrigated with nutrient solution. In fact, plants cultivated in vermiculite enhanced leaf area and leaf fresh weight, together with high foliar concentrations of N, Mg, Mn, Fe, Na, clorophylls and carotenoids. Furthermore, increased succulence and Na concentration of edible parts of glacier lettuce grown in vermiculite can offer more interesting taste, consistence and nutrient content for consumers.
Higlights
Hydroponic and vermiculite cultures led to optimum crystallinum growth.
Peat pot culture did not seem to be an adequate substrate to cultivate crystallinum.
Ice plants grown in vermiculite presented highest leaf fresh yield and high foliar N, Mg, Mn, Fe, Na, chlorophyll and carotenoid concentrations.Mesembryanthemum crystallinum is considered a drought and saline stress-tolerant plant with many biological activities that has been revalued as cool flavouring plant. The objective of this work was to assess optimum mode of cultivation of M. crystallinum to produce edible parts under greenhouse conditions. Therefore, three soilless media were evaluated: peat, vermiculite and hydroponic culture. Pot culture in peat did not result to be a good substrate for iceplant, with little biomass production. However, vermiculite and hydroponics allowed optimum growth of M. crystallinum, with a significantly greater yield in plants grown in vermiculite irrigated with nutrient solution. In fact, plants cultivated in vermiculite enhanced leaf area and leaf fresh weight, together with high foliar concentrations of N, Mg, Mn, Fe, Na, clorophylls and carotenoids. Furthermore, increased succulence and Na concentration of edible parts of glacier lettuce grown in vermiculite can offer more interesting taste, consistence and nutrient content for consumers.
Higlights
Hydroponic and vermiculite cultures led to optimum crystallinum growth.
Peat pot culture did not seem to be an adequate substrate to cultivate crystallinum.
Ice plants grown in vermiculite presented highest leaf fresh yield and high foliar N, Mg, Mn, Fe, Na, chlorophyll and carotenoid concentrations
Influence of sugarcane straw on weed germination control: Weed control in sugarcane
No full textThis research studied the effectiveness of herbicide treatments in weed control and during different periods of emergence, when applied to varying amounts of straw. The experiment was conducted in a greenhouse with pre-emergent herbicides: amicarbazone, metribuzin, indaziflam, isoxaflutole, amicarbazone + indaziflam, metribuzin + indaziflam, and isoxaflutole + indaziflam, against three species (Sorghum halepense, Rottboellia exaltata, and Mucuna aterrima). The experimental design was completely randomized in a 5x4 factorial scheme, with five amounts of straw (0, 1, 2, 3, and 5 t/ha) and four periods of weed emergence (0, 30, 60, and 90 days after treatments). The residual control of indaziflam was influenced by the amount of straw. Metribuzin presented a low residual control, while isoxaflutole was not affected by the amount of straw. Amicarbazone offered residual control for Mucuna aterrima. The association between indaziflam + isoxaflutole displayed a suitable residual control against Sorghum halepense and Rottboellia exaltata. The association of indaziflam + metribuzin adequately controlled Mucuna aterrima and Sorghum halepense. herbicide physical-chemical characteristics can influence their performance, and the association of products may increase residual and weed spectrum control.
Highlights
This partial or total removal of remaining sugarcane straw from the soil surface alters weeds dynamics in sugarcane fields. In this situation we have monocot and dicot weeds infesting the sugarcane crops.
Among these species, some plants are even more difficult to control, such as Sorghum halepense, Rottboellia exaltata, and Mucuna aterrima
Indaziflam herbicide presented a better performance in controlling monocotyledonous plants than eudicot plants.
The herbicides amicarbazone and metribuzin presented adequate control of Mucuna aterrima despite having lower residual control.
The association of indaziflam + metribuzin, resulted in satisfactory results for Mucuna aterrima, Sorghum halepense, and Rottboellia exaltata.This research studied the effectiveness of herbicide treatments in weed control and during different periods of emergence, when applied to varying amounts of straw. The experiment was conducted in a greenhouse with pre-emergent herbicides: amicarbazone, metribuzin, indaziflam, isoxaflutole, amicarbazone + indaziflam, metribuzin + indaziflam, and isoxaflutole + indaziflam, against three species (Sorghum halepense, Rottboellia exaltata, and Mucuna aterrima). The experimental design was completely randomized in a 5x4 factorial scheme, with five amounts of straw (0, 1, 2, 3, and 5 t/ha) and four periods of weed emergence (0, 30, 60, and 90 days after treatments). The residual control of indaziflam was influenced by the amount of straw. Metribuzin presented a low residual control, while isoxaflutole was not affected by the amount of straw. Amicarbazone offered residual control for Mucuna aterrima. The association between indaziflam + isoxaflutole displayed a suitable residual control against Sorghum halepense and Rottboellia exaltata. The association of indaziflam + metribuzin adequately controlled Mucuna aterrima and Sorghum halepense. herbicide physical-chemical characteristics can influence their performance, and the association of products may increase residual and weed spectrum control.
Highlights
This partial or total removal of remaining sugarcane straw from the soil surface alters weeds dynamics in sugarcane fields. In this situation we have monocot and dicot weeds infesting the sugarcane crops.
Among these species, some plants are even more difficult to control, such as Sorghum halepense, Rottboellia exaltata, and Mucuna aterrima
Indaziflam herbicide presented a better performance in controlling monocotyledonous plants than eudicot plants.
The herbicides amicarbazone and metribuzin presented adequate control of Mucuna aterrima despite having lower residual control.
The association of indaziflam + metribuzin, resulted in satisfactory results for Mucuna aterrima, Sorghum halepense, and Rottboellia exaltata
Development and validation of diagrammatic scales to evaluate damage by the two-spotted spider mite (Tetranychus urticae) in peanut
Get PDFArgentina is the second largest peanut (Arachis hypogaea L.) exporter in the world. The main peanut pest in our country is the two-spotted spider mite (Tetranychus urticae Koch 1836). To date, there is no validated method to quantify this pest. The aim of this work was to develop and validate a logarithmic diagrammatic scale to assess damage by the two-spotted spider mite in peanut. In 2015-16, 200 leaflets were collected from a plot infested with the pest. Damaged leaf area (DLA) was calculated using SisCob software. Six-, seven-, eight- and nine-class scales were proposed. Mean values for each class and scale were obtained with 2-LOG. Leaflets were analyzed by 13 raters who used the four proposed scales. Precision and accuracy were determined by simple linear regression between the DLA and estimated damaged leaf area. Reproducibility was determined by linear regression between estimates of raters combined in pairs. The seven-class scale was the best validated one for all the parameters. Most raters showed constant deviations and overestimated DLA, whereas only one rater presented systematic deviations. This seven-class scale is the first developed and validated one to evaluate two-spotted spider mite damage to peanut in Argentina.
Highlights
According to the validation results, the seven-class diagrammatic scale was the best one in terms of accuracy, precision and reproducibility with values above 0.80, 0.75 and 0.75 respectively.
The scales are useful tools for pest assessment, fundamental parameters for integrated pest management.
The seven-class scale is the first one developed and validated for evaluating damage by the two-spotted spider mite in peanut crop in Argentina.
With this scale a loss function will be calculate which will allow the estimation of the EIL of this pest.Argentina is the second largest peanut (Arachis hypogaea L.) exporter in the world. The main peanut pest in our country is the two-spotted spider mite (Tetranychus urticae Koch 1836). To date, there is no validated method to quantify this pest. The aim of this work was to develop and validate a logarithmic diagrammatic scale to assess damage by the two-spotted spider mite in peanut. In 2015-16, 200 leaflets were collected from a plot infested with the pest. Damaged leaf area (DLA) was calculated using SisCob software. Six-, seven-, eight- and nine-class scales were proposed. Mean values for each class and scale were obtained with 2-LOG. Leaflets were analyzed by 13 raters who used the four proposed scales. Precision and accuracy were determined by simple linear regression between the DLA and estimated damaged leaf area. Reproducibility was determined by linear regression between estimates of raters combined in pairs. The seven-class scale was the best validated one for all the parameters. Most raters showed constant deviations and overestimated DLA, whereas only one rater presented systematic deviations. This seven-class scale is the first developed and validated one to evaluate two-spotted spider mite damage to peanut in Argentina.
Highlights
According to the validation results, the seven-class diagrammatic scale was the best one in terms of accuracy, precision and reproducibility with values above 0.80, 0.75 and 0.75 respectively.
The scales are useful tools for pest assessment, fundamental parameters for integrated pest management.
The seven-class scale is the first one developed and validated for evaluating damage by the two-spotted spider mite in peanut crop in Argentina.
With this scale a loss function will be calculate which will allow the estimation of the EIL of this pest
Soil compaction response to wheel traffic in the Rolling Pampas region of Argentina
Get PDFThe present work shows the effects of the different agricultural wheels traffic on the soil physical properties on a Typic Argiudoll soil worked under no-tillage cropping system. Soil compaction produced by traffic was quantified through these parameters: a) cone index, b) rut depth and c) soil water content at the traffic moment. Grain chaser, sprayer, harvester combine and tractor equipped with commonly used wheels in the study area were tested. The main results obtained showed that the tyres with the highest inflation pressure and tyre ground pressures produced the highest values of cone index and rut depth. Typic Argiudoll soil worked under continuous no-tillage cropping system is not able to constrain topsoil and subsoil compaction when it is wheeled by tyre with ground pressures greater than 77.6 kPa.
Highlights
Soil compaction causes a reduction in root growth and yield in many crops.
Soil under a no-tillage system does not limit topsoil and subsoil compaction when wheeled by tyres with ground pressures greater than 77.6 kPa
When the machinery load increases on soils with high bearing capacity (soils under a long-term no-tillage system), the subsoil compaction problems increase.The present work shows the effects of the different agricultural wheels traffic on the soil physical properties on a Typic Argiudoll soil worked under no-tillage cropping system. Soil compaction produced by traffic was quantified through these parameters: a) cone index, b) rut depth and c) soil water content at the traffic moment. Grain chaser, sprayer, harvester combine and tractor equipped with commonly used wheels in the study area were tested. The main results obtained showed that the tyres with the highest inflation pressure and tyre ground pressures produced the highest values of cone index and rut depth. Typic Argiudoll soil worked under continuous no-tillage cropping system is not able to constrain topsoil and subsoil compaction when it is wheeled by tyre with ground pressures greater than 77.6 kPa.
Highlights
Soil compaction causes a reduction in root growth and yield in many crops.
Soil under a no-tillage system does not limit topsoil and subsoil compaction when wheeled by tyres with ground pressures greater than 77.6 kPa
When the machinery load increases on soils with high bearing capacity (soils under a long-term no-tillage system), the subsoil compaction problems increase
First report of Berkeleyomyces basicola (synonymous: Thielaviopsis basicola) on roots of sweet potato (Ipomoea batatas (L.) Lam) in Argentina
Get PDFSymptomatic sweet potato cv Arapey INIA samples were collected from a commercial production field in Colonia Molina, Guaymallén department, Mendoza province, Argentina. They showed dark rounded lesions, sometimes coalescing with white granular mycelium. Fungus was obtained from symptomatic sweet potatoes, which represented the generalized infection that affected the crop. They were seeded in PDA with streptomycin sulfate and incubated for seven days at 21°C, alternating white/black (UV400nm) light. Observations with an optical microscope revealed the presence of hyaline, not septated, cylindrical endoconidia with rounded ends. They were 8-16 μm length and 4–6 μm width. Phialides were 43-46 μm length, rounded bases (7-9 μm width) and tapering to the neck´s tip (4-6 μm width). Brown chlamydospores (aleuriospores), 9-13 μm length and 8-12 μm width, in chains of 2-8 spores were observed. For molecular identification, total genomic DNA was extracted. ITS fragment of 565 pb was amplified using ITS5/ITS4 primers and sequenced. The sequence indicated 99% identity with Berkeleyomyces basicola (synonymous: Thielaviopsis basicola). This was deposited in GenBank as (KX580957) (CBS: C430.74, Gen Bank accession number AF275482.1). This is the first report of B. basicola in sweet potato in Argentina, a potential threat to storage root yields.
Highlights:
Sweet potato black root rot, new disease in Argentina.
First report of Berkeleyomyces basicola causing black root rot on sweet potato in Mendoza, Argentina.Symptomatic sweet potato cv Arapey INIA samples were collected from a commercial production field in Colonia Molina, Guaymallén department, Mendoza province, Argentina. They showed dark rounded lesions, sometimes coalescing with white granular mycelium. Fungus was obtained from symptomatic sweet potatoes, which represented the generalized infection that affected the crop. They were seeded in PDA with streptomycin sulfate and incubated for seven days at 21°C, alternating white/black (UV400nm) light. Observations with an optical microscope revealed the presence of hyaline, not septated, cylindrical endoconidia with rounded ends. They were 8-16 μm length and 4–6 μm width. Phialides were 43-46 μm length, rounded bases (7-9 μm width) and tapering to the neck´s tip (4-6 μm width). Brown chlamydospores (aleuriospores), 9-13 μm length and 8-12 μm width, in chains of 2-8 spores were observed. For molecular identification, total genomic DNA was extracted. ITS fragment of 565 pb was amplified using ITS5/ITS4 primers and sequenced. The sequence indicated 99% identity with Berkeleyomyces basicola (synonymous: Thielaviopsis basicola). This was deposited in GenBank as (KX580957) (CBS: C430.74, Gen Bank accession number AF275482.1). This is the first report of B. basicola in sweet potato in Argentina, a potential threat to storage root yields.
Highlights:
Sweet potato black root rot, new disease in Argentina.
First report of Berkeleyomyces basicola causing black root rot on sweet potato in Mendoza, Argentina