Revista de la Facultad de Ciencias Agrarias
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Arthropods of the Limarí River basin (Coquimbo Region, Chile): taxonomic composition in agricultural ecosystems
Get PDFThe Limarí valley, located in the Coquimbo Region of Chile, is an important agricultural area that is immersed in the transverse valleys of the Norte Chico. In recent decades, the continuous expansion of agriculture towards dry land zones has favored the migration and establishment of potential pests, such as arthropods, that may affect crops or be zoonotic agents. Based on the limited knowledge we have about the arthropod group present in the Limarí basin, our objective is to describe the taxonomic composition of the assemblage of economically important arthropods inhabiting this basin of the semiarid region of Chile. After reviewing historical data, specimen collections, and the specialized literature, a total of 414 arthropod species were recorded. Of the total number of species recorded, 92.5% were insects, the most diverse taxon, with 11 orders. Arachnids, in turn, were represented only by Acari with 31 species. The most widely represented orders of insects were Coleoptera, Hemiptera, and Lepidoptera. Within Coleoptera the most species-rich families were, in decreasing order of importance, Curculionidae, Coccinellidae, Cerambycidae, Scarabaeidae, Chrysomelidae (Bruchinae), Ptinidae, and Bostrichidae; within Hemiptera these were Aphididae, Diaspididae, Coccidae, Pseudococcidae, Pentatomidae and Rhopalidae; and within Lepidoptera they were Noctuidae and Tortricidae. We hope this study serves as a starting point for identifying the most diverse arthropod groups and developing pest monitoring and control programs.
Highlights:
A large percentage of phytophagous species, mainly belonging to Acari, Lepidoptera, Hemiptera and Coleoptera, were registered in the Limarí basin.
Some families of agricultural importance (Aleyrodidae, Aphididae, Coccidae, Diaspididae, Margarodidae, Pseudococcidae), were observed in large agricultural crops in the basin (e.g., vines, oranges, mandarins, lemon trees, avocado trees, walnuts, olive trees, vegetable crops).
A smaller fraction corresponded to the group of predators and parasitoids, mainly represented by Coleoptera (Coccinellidae), Neuroptera (Chrysopidae) and Hymenoptera (Braconidae, Encyrtidae, Ichneumonidae, Platygastridae, Signiphoridae).
The richness and spatial records of arthropods were mostly concentrated between the city of Ovalle and the estuary of Punitaqui - the areas with most intense agricultural activity in the Limarí basin.The Limarí valley, located in the Coquimbo Region of Chile, is an important agricultural area that is immersed in the transverse valleys of the Norte Chico. In recent decades, the continuous expansion of agriculture towards dry land zones has favored the migration and establishment of potential pests, such as arthropods, that may affect crops or be zoonotic agents. Based on the limited knowledge we have about the arthropod group present in the Limarí basin, our objective is to describe the taxonomic composition of the assemblage of economically important arthropods inhabiting this basin of the semiarid region of Chile. After reviewing historical data, specimen collections, and the specialized literature, a total of 414 arthropod species were recorded. Of the total number of species recorded, 92.5% were insects, the most diverse taxon, with 11 orders. Arachnids, in turn, were represented only by Acari with 31 species. The most widely represented orders of insects were Coleoptera, Hemiptera, and Lepidoptera. Within Coleoptera the most species-rich families were, in decreasing order of importance, Curculionidae, Coccinellidae, Cerambycidae, Scarabaeidae, Chrysomelidae (Bruchinae), Ptinidae, and Bostrichidae; within Hemiptera these were Aphididae, Diaspididae, Coccidae, Pseudococcidae, Pentatomidae and Rhopalidae; and within Lepidoptera they were Noctuidae and Tortricidae. We hope this study serves as a starting point for identifying the most diverse arthropod groups and developing pest monitoring and control programs.
Highlights:
A large percentage of phytophagous species, mainly belonging to Acari, Lepidoptera, Hemiptera and Coleoptera, were registered in the Limarí basin.
Some families of agricultural importance (Aleyrodidae, Aphididae, Coccidae, Diaspididae, Margarodidae, Pseudococcidae), were observed in large agricultural crops in the basin (e.g., vines, oranges, mandarins, lemon trees, avocado trees, walnuts, olive trees, vegetable crops).
A smaller fraction corresponded to the group of predators and parasitoids, mainly represented by Coleoptera (Coccinellidae), Neuroptera (Chrysopidae) and Hymenoptera (Braconidae, Encyrtidae, Ichneumonidae, Platygastridae, Signiphoridae).
The richness and spatial records of arthropods were mostly concentrated between the city of Ovalle and the estuary of Punitaqui - the areas with most intense agricultural activity in the Limarí basin
Mixtures between glyphosate formulations and ACCase-inhibiting herbicides in the control of Chloris elata
Get PDFChloris elata is an important weed for grain and sugarcane crops. In addition to its aggressiveness, it may show resistance to glyphosate herbicide. In this context, the aim of this study was to assess the effectiveness of glyphosate formulations, isolated or in association with ACCase inhibitors, in controlling C. elata (putatively resistant to glyphosate) at different developmental stages. Four experiments were conducted in a completely randomized design. Treatments consisted of glyphosate application under different formulations with ACCase inhibitors, isolated or in mixtures. Applications were carried out at the stages of four fully expanded leaves in Experiment I, four tillers in Experiment II, and at regrowth of the four-tiller plants in Experiments III and IV. Applications of glyphosate isopropylamine salt associated with sethoxydim or clethodim showed to be among the best treatments in Experiments I, II, and III, presenting control scores equal to or greater than 90%. However, not even these treatments could provide successful control in Experiment IV. Moreover, and regardless of the formulation, isolated glyphosate, showed 85% (Experiment III) and 50% (Experiment IV) maximum controls. Associations between glyphosate and ACCase-inhibiting herbicides showed to be effective in controlling C. elata, especially at early developmental stages. In general, isolated herbicides provided lower percentages of control, as well as higher values of dry matter. Sole herbicide applications were not effective in controlling C. elata (putatively resistant to glyphosate), regardless of the developmental stage.
Highlights:
Mixtures between glyphosate and ACCase-inhibiting have been shown to be effective in C. elata control, especially in the early development stages.
Isolated herbicide applications were not effective in controlling C. elata, regardless of the development stage.
Mixtures between glyphosate and ACCase-inhibiting is more important in the control than the glyphosate formulation or ACCase-inhibiting used.Chloris elata is an important weed for grain and sugarcane crops. In addition to its aggressiveness, it may show resistance to glyphosate herbicide. In this context, the aim of this study was to assess the effectiveness of glyphosate formulations, isolated or in association with ACCase inhibitors, in controlling C. elata (putatively resistant to glyphosate) at different developmental stages. Four experiments were conducted in a completely randomized design. Treatments consisted of glyphosate application under different formulations with ACCase inhibitors, isolated or in mixtures. Applications were carried out at the stages of four fully expanded leaves in Experiment I, four tillers in Experiment II, and at regrowth of the four-tiller plants in Experiments III and IV. Applications of glyphosate isopropylamine salt associated with sethoxydim or clethodim showed to be among the best treatments in Experiments I, II, and III, presenting control scores equal to or greater than 90%. However, not even these treatments could provide successful control in Experiment IV. Moreover, and regardless of the formulation, isolated glyphosate, showed 85% (Experiment III) and 50% (Experiment IV) maximum controls. Associations between glyphosate and ACCase-inhibiting herbicides showed to be effective in controlling C. elata, especially at early developmental stages. In general, isolated herbicides provided lower percentages of control, as well as higher values of dry matter. Sole herbicide applications were not effective in controlling C. elata (putatively resistant to glyphosate), regardless of the developmental stage.
Highlights:
Mixtures between glyphosate and ACCase-inhibiting have been shown to be effective in C. elata control, especially in the early development stages.
Isolated herbicide applications were not effective in controlling C. elata, regardless of the development stage.
Mixtures between glyphosate and ACCase-inhibiting is more important in the control than the glyphosate formulation or ACCase-inhibiting used
Lotus tenuis and Schedonorus arundinaceus co-culture exposed to defoliation and water stress
Get PDFThe present study aimed to investigate the effect of defoliation frequency (low and high) and water stress (excess or deficit) on biomass production, P and N nutrition, and symbiosis with native soil microorganisms on a Lotus tenuis and Schedonorus arundinaceus co-culture in a pot experiment. Combined effects of defoliation frequency and water stress affected plant accumulated shoot biomass. L. tenuis root biomass decreased in response to defoliation and water stress, while S. arundinaceus root biomass was similar between non-defoliated and defoliated plants, at all water levels. Low and high frequencies of defoliation in a waterlogged soil can be considered the most stressful scenario for L. tenuis and S. arundinaceus co-culture. Colonization of arbuscular mycorrhizal fungi in L. tenuis roots and dark septate endophytes colonization in S. arundinaceus roots were affected by both factors, whereas arbuscular mycorrhizal colonization in S. arundinaceus was affected only by water stress. Both plants tolerated defoliation and water stress due to the interaction between the translocation of nutrients and carbon compounds from roots to shoots, and P and N absorption (plus N2 fixation in L. tenuis).
Highlights:
Both plants tolerated defoliation and water stress due to the interaction between the translocation of nutrients and carbon compounds from roots to shoots, and P and N absorption (plus N2 fixation in tenuis).
Low and high frequencies of defoliation in a waterlogged soil can be considered the most stressful scenario for tenuis and S. arundinaceus co-culture.
Defoliation frequency increased AM colonization in plant roots under well watered and water deficit conditions.
arundinaceus roots were co-colonized by AM fungi and DSE.
Promoting the presence of tenuis through low defoliation frequency would improve forage yield and quality with the maintenance of AM symbiosis in legume–grass communities.The present study aimed to investigate the effect of defoliation frequency (low and high) and water stress (excess or deficit) on biomass production, P and N nutrition, and symbiosis with native soil microorganisms on a Lotus tenuis and Schedonorus arundinaceus co-culture in a pot experiment. Combined effects of defoliation frequency and water stress affected plant accumulated shoot biomass. L. tenuis root biomass decreased in response to defoliation and water stress, while S. arundinaceus root biomass was similar between non-defoliated and defoliated plants, at all water levels. Low and high frequencies of defoliation in a waterlogged soil can be considered the most stressful scenario for L. tenuis and S. arundinaceus co-culture. Colonization of arbuscular mycorrhizal fungi in L. tenuis roots and dark septate endophytes colonization in S. arundinaceus roots were affected by both factors, whereas arbuscular mycorrhizal colonization in S. arundinaceus was affected only by water stress. Both plants tolerated defoliation and water stress due to the interaction between the translocation of nutrients and carbon compounds from roots to shoots, and P and N absorption (plus N2 fixation in L. tenuis).
Highlights:
Both plants tolerated defoliation and water stress due to the interaction between the translocation of nutrients and carbon compounds from roots to shoots, and P and N absorption (plus N2 fixation in tenuis).
Low and high frequencies of defoliation in a waterlogged soil can be considered the most stressful scenario for tenuis and S. arundinaceus co-culture.
Defoliation frequency increased AM colonization in plant roots under well watered and water deficit conditions.
arundinaceus roots were co-colonized by AM fungi and DSE.
Promoting the presence of tenuis through low defoliation frequency would improve forage yield and quality with the maintenance of AM symbiosis in legume–grass communities
Protected designation of origin as driver of change in goat production systems: Beyond added value
Get PDFProtected Designation of Origin (PDO) is one of the EU tools for rural development. Most of the literature on this subject is focused on premium prices and consumers’ willingness to pay for local products, since PDO and other labels aim to provide premium incomes for farmers. Our assumption is that PDO drives unexpected changes of farming styles not only related to processing or market strategies but also related to local resources using and to stablishing of different approach to agriculture and food production. We analyzed the PDO Queso Palmero (La Palma cheese) as a case of a dual label system (brand–certification common label) because it gives us the opportunity to compare farmers involved in a PDO scheme with farmers who works outside such systems. We conclude that private brands are more important than common label certification in price formation, but both are complementary, since PDO reinforces farmers’ efforts to improve quality. Beyond premium price, PDO also drives a radical change in farm structures, since it reconnects products to local resources (grazing vs intensification) and redesigns relationships with markets (shortening and diversifying chains and widening product offer). This change is characterized by implementation of new farming strategies in the context of PDO structure that coexist with classical farming strategies closer to intensification, not only in terms of productivity but also in terms of decoupling from local resources and productive and market specialization. Therefore, PDO is a powerful tool for rural development in a wide sense (resilience, empowerment, local capacity and network formation among others) far beyond its narrow remit of promoting economic growth (local or regional). Therefore, the coupling with local resources and the strength of local network and relationships as source of resilience, knowledge and capabilities improvement, have to be included in performance assessment of GIs in order to broaden the appraisal of role in regional development.
Highlights
PDO as institution is a powerful tool of farm transformation not only a protection structure of collective heritage or asset.
Private brand effect on price is larger than common label effect (PDO label).
PDO as institution leads radical changes of goat production systems from more production – oriented toward more market – oriented styles.
Market chains and product diversification, focusing on quality, concern about consumers and coupling with local resources are distinctive features of farms involved in PDO.Protected Designation of Origin (PDO) is one of the EU tools for rural development. Most of the literature on this subject is focused on premium prices and consumers’ willingness to pay for local products, since PDO and other labels aim to provide premium incomes for farmers. Our assumption is that PDO drives unexpected changes of farming styles not only related to processing or market strategies but also related to local resources using and to stablishing of different approach to agriculture and food production. We analyzed the PDO Queso Palmero (La Palma cheese) as a case of a dual label system (brand–certification common label) because it gives us the opportunity to compare farmers involved in a PDO scheme with farmers who works outside such systems. We conclude that private brands are more important than common label certification in price formation, but both are complementary, since PDO reinforces farmers’ efforts to improve quality. Beyond premium price, PDO also drives a radical change in farm structures, since it reconnects products to local resources (grazing vs intensification) and redesigns relationships with markets (shortening and diversifying chains and widening product offer). This change is characterized by implementation of new farming strategies in the context of PDO structure that coexist with classical farming strategies closer to intensification, not only in terms of productivity but also in terms of decoupling from local resources and productive and market specialization. Therefore, PDO is a powerful tool for rural development in a wide sense (resilience, empowerment, local capacity and network formation among others) far beyond its narrow remit of promoting economic growth (local or regional). Therefore, the coupling with local resources and the strength of local network and relationships as source of resilience, knowledge and capabilities improvement, have to be included in performance assessment of GIs in order to broaden the appraisal of role in regional development.
Highlights
PDO as institution is a powerful tool of farm transformation not only a protection structure of collective heritage or asset.
Private brand effect on price is larger than common label effect (PDO label).
PDO as institution leads radical changes of goat production systems from more production – oriented toward more market – oriented styles.
Market chains and product diversification, focusing on quality, concern about consumers and coupling with local resources are distinctive features of farms involved in PDO
Effect of rearing system and sex on the composition and fatty acid profile of Andinoacara rivulatus meat from Ecuador
Get PDFThis study evaluated the influence of rearing system (cultured vs. wild rearing systems), and fish sex on carcass and flesh traits of A. rivulatus, raised in Ecuador. Three hundred mature specimens from A. rivulatus were captured, 150 from each origin. Slaughter yield and dress-out resulted similar for both rearing system, and average fillet yield for cultured fish was significantly higher than for wild fish, while cooking loss was significantly lower. Dress-out was significantly higher in females. Significant differences were found in wet percentage, ash, fat and protein content in both rearing systems, but only wet percentage was significantly affected by sex. Palmitic, oleic and arachidonic acids had the maximum percentage of saturated (SFA) and mono/poly unsaturated (MUFA/ PUFA) fatty acids, respectively. In cultured and wild fish, differentiations were also found in PUFA/SFA, docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA), atherogenicity (IA), and thrombogenicity (IT) indices, along with P, K, Mg, Cu and Fe. Sex and rearing system significantly influenced most of the analyzed characteristics of carcass and flesh of A. rivulatus. Fillet high yield and its proximate composition categorize A. rivulatus as a suitable food. These results provide valuable nutritional information about native species for consumers in Ecuador.
Highlights:
The rearing system (cultured vs. wild rearing systems), and fish sex affect the carcass and flesh traits of A. rivulatus.
Fillet high yield and its proximate composition categorize A. rivulatus as a suitable food.
The proximate composition of fillet from cultured A. rivulatus is more adequate than those of wild A. rivulatus.
The cultured A. rivulatus contains higher n-3 and n-6 PUFA percentages and adequate n-3/n-6 ratio.This study evaluated the influence of rearing system (cultured vs. wild rearing systems), and fish sex on carcass and flesh traits of A. rivulatus, raised in Ecuador. Three hundred mature specimens from A. rivulatus were captured, 150 from each origin. Slaughter yield and dress-out resulted similar for both rearing system, and average fillet yield for cultured fish was significantly higher than for wild fish, while cooking loss was significantly lower. Dress-out was significantly higher in females. Significant differences were found in wet percentage, ash, fat and protein content in both rearing systems, but only wet percentage was significantly affected by sex. Palmitic, oleic and arachidonic acids had the maximum percentage of saturated (SFA) and mono/poly unsaturated (MUFA/ PUFA) fatty acids, respectively. In cultured and wild fish, differentiations were also found in PUFA/SFA, docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA), atherogenicity (IA), and thrombogenicity (IT) indices, along with P, K, Mg, Cu and Fe. Sex and rearing system significantly influenced most of the analyzed characteristics of carcass and flesh of A. rivulatus. Fillet high yield and its proximate composition categorize A. rivulatus as a suitable food. These results provide valuable nutritional information about native species for consumers in Ecuador.
Highlights:
The rearing system (cultured vs. wild rearing systems), and fish sex affect the carcass and flesh traits of A. rivulatus.
Fillet high yield and its proximate composition categorize A. rivulatus as a suitable food.
The proximate composition of fillet from cultured A. rivulatus is more adequate than those of wild A. rivulatus.
The cultured A. rivulatus contains higher n-3 and n-6 PUFA percentages and adequate n-3/n-6 ratio
Prioritization of vigor QTL-associated genes for future genome-directed Vitis breeding: Priorización de genes relacionados a vigor en Vitis
No full textVigor control in grapevine may become especially important under climate change. A better understanding of gene-phenotype relationships is required in order to exploit plant genomics for breeding purposes. This research aims to use quantitative trait loci (QTLs) for vigor identified in the progeny from a cross of Ramsey (Vitis champinii) × Riparia Gloire (V. riparia). Genes located 700 kb up and downstream from each QTL position were interrogated for functional enrichment through ShinyGO online tool, based on the gene ontology annotation of Vitis vinifera PN40024. Key biological processes like phloem and xylem development, cell cycle, response to hormones, amino acid transport, tissue development, sugar metabolism, nitrogen transport, and stress/immune responses, showed functional enrichment. Integral response to light and auxin might be required for fine molecular tuning of vegetative growth in Vitis. Fifty out of 1318 candidate genes were prioritized, reducing their amount to a manageable number of candidates for further directed breeding strategies.
Highlights
Plant vigor control may become especially important under climate change.
Genes from various vigor-related QTLs were interrogated for functional enrichment.
The analysis reduced candidate gene number based on marker proximity and functional enrichment, constituting a suitable shortcut for target-directed genome-guided breeding strategies.
Three TFs are strong candidates for targeted breeding: TIF - HY5, TIF - SUS1, TIF - VOZ1 potentially enhance growth by relating light response to hormone activation, and then to photosynthesis and morphogenesis.
Vigor control in grapevine may become especially important under climate change. A better understanding of gene-phenotype relationships is required in order to exploit plant genomics for breeding purposes. This research aims to use quantitative trait loci (QTLs) for vigor identified in the progeny from a cross of Ramsey (Vitis champinii) × Riparia Gloire (V. riparia). Genes located 700 kb up and downstream from each QTL position were interrogated for functional enrichment through ShinyGO online tool, based on the gene ontology annotation of Vitis vinifera PN40024. Key biological processes like phloem and xylem development, cell cycle, response to hormones, amino acid transport, tissue development, sugar metabolism, nitrogen transport, and stress/immune responses, showed functional enrichment. Integral response to light and auxin might be required for fine molecular tuning of vegetative growth in Vitis. Fifty out of 1318 candidate genes were prioritized, reducing their amount to a manageable number of candidates for further directed breeding strategies.
Highlights
Plant vigor control may become especially important under climate change.
Genes from various vigor-related QTLs were interrogated for functional enrichment.
The analysis reduced candidate gene number based on marker proximity and functional enrichment, constituting a suitable shortcut for target-directed genome-guided breeding strategies.
Three TFs are strong candidates for targeted breeding: TIF - HY5, TIF - SUS1, TIF - VOZ1 potentially enhance growth by relating light response to hormone activation, and then to photosynthesis and morphogenesis
Salmea scandens (Asteraceae) extracts inhibit the growth of Fusarium oxysporum and Alternaria solani pathogens of tomato: Salmea scandens extracts inhibit the growth of tomato pathogens
No full textTomatoes are affected by fungi of the genera Fusarium and Alternaria, reducing the quantity and quality of the fruit.Since plant extracts are an alternative for the control of phytopathogenic fungi, the antifungal effect of Salmea scandens extracts was evaluated against Fusarium oxysporum and Alternaria solani and the functional groups of the chemical constituents were identified.The aqueous extracts were obtained by three techniques (soxhlet, assisted ultrasound and maceration) and three solvents (water, acetone and ethyl ether), these were evaluated against F. oxysporum in poisoned medium and A. solani in tomato fruit. The functional groups were identified by the Fourier Transform Infrared Spectroscopy (FTIR) technique. The best extraction technique for S. scandenswas soxhlet with all three solvents. Maceration-acetone extracts at concentrations of 4000 and 5000 ppm showed increased antifungal activity against F. oxysporum and A. solani. The FTIR analysis confirmed the presence of carboxylic acids, aldehydes, ketones and aromatic compounds as the possible responsible for the antifungal activity.S. scandensextracts have a high potential to be used as a preventive treatment in the control of F. oxysporum and A. solani.
Highlights
The highest mass/volume extraction efficiency yield was with the soxhlet technique using water as a solvent.
Extracts obtained by maceration-acetone technique, caused the strongest Fusarium oxysporum inhibition.
The maceration-acetone extract at 5000 ppm, showed higher inhibition of A. solani mycelial growth than the commercial fungicide Hymexazol.Tomatoes are affected by fungi of the genera Fusarium and Alternaria, reducing the quantity and quality of the fruit.Since plant extracts are an alternative for the control of phytopathogenic fungi, the antifungal effect of Salmea scandens extracts was evaluated against Fusarium oxysporum and Alternaria solani and the functional groups of the chemical constituents were identified.The aqueous extracts were obtained by three techniques (soxhlet, assisted ultrasound and maceration) and three solvents (water, acetone and ethyl ether), these were evaluated against F. oxysporum in poisoned medium and A. solani in tomato fruit. The functional groups were identified by the Fourier Transform Infrared Spectroscopy (FTIR) technique. The best extraction technique for S. scandenswas soxhlet with all three solvents. Maceration-acetone extracts at concentrations of 4000 and 5000 ppm showed increased antifungal activity against F. oxysporum and A. solani. The FTIR analysis confirmed the presence of carboxylic acids, aldehydes, ketones and aromatic compounds as the possible responsible for the antifungal activity.S. scandensextracts have a high potential to be used as a preventive treatment in the control of F. oxysporum and A. solani.
Highlights
The highest mass/volume extraction efficiency yield was with the soxhlet technique using water as a solvent.
Extracts obtained by maceration-acetone technique, caused the strongest Fusarium oxysporum inhibition.
The maceration-acetone extract at 5000 ppm, showed higher inhibition of A. solani mycelial growth than the commercial fungicide Hymexazol
The role of fuel prices in spatial price transmission between horticultural markets: empirical analysis from a developing country
Get PDFThis article aims to analyze how fuel prices impact spatial price transmission between two Chilean horticultural wholesale markets. We implement a regime-dependent VECM where price transmission parameters depend on dynamics imposed by a stationary exogenous variable (fuel price). We identified two price transmission regimes characterized by different equilibrium relationships and short-run adjustment processes. This implies that fuel prices affect price transmission elasticities and intermarket adjustment speeds. Our results show increasing marketing costs as farm to market distance grows. This impact depends on each product’s attributes.
Highlights
This article analyzes the effect of fuel prices on the price transmission mechanism between the most relevant Chilean horticultural wholesale markets.
A regime-dependent Vector Error Correction Model where price transmission parameters depend on fuel price was implemented.
Clear evidence of the role played by fuel prices for in horizontal price transmission between the wholesale markets considered in this study was found.
This situation supports the idea that regardless of quantities traded in regional markets, the major effect of price adjustment is a result of the high demand, distances and market concentration of a central market. This impact depends on each product’s attributes.This article aims to analyze how fuel prices impact spatial price transmission between two Chilean horticultural wholesale markets. We implement a regime-dependent VECM where price transmission parameters depend on dynamics imposed by a stationary exogenous variable (fuel price). We identified two price transmission regimes characterized by different equilibrium relationships and short-run adjustment processes. This implies that fuel prices affect price transmission elasticities and intermarket adjustment speeds. Our results show increasing marketing costs as farm to market distance grows. This impact depends on each product’s attributes.
Highlights
This article analyzes the effect of fuel prices on the price transmission mechanism between the most relevant Chilean horticultural wholesale markets.
A regime-dependent Vector Error Correction Model where price transmission parameters depend on fuel price was implemented.
Clear evidence of the role played by fuel prices for in horizontal price transmission between the wholesale markets considered in this study was found.
This situation supports the idea that regardless of quantities traded in regional markets, the major effect of price adjustment is a result of the high demand, distances and market concentration of a central market. This impact depends on each product’s attributes
Evaluation of tolerance to Fusarium oxysporum and Fusarium solani in Virginia-type tobacco (Nicotiana tabacum L.) varieties under controlled conditions in Northwestern Argentina
Get PDFThe production of tobacco (Nicotiana tabacum L.) in Argentina is centered in the northwestern region (NWA), where the incidence of root rots and stem diseases caused by Fusarium spp. has increased considerably in recent years. This study aimed to evaluate the pathogenicity levels of isolates of the F. oxysporum and F. solani complexes in different varieties of Virginia Type tobacco. The commercial varieties MB47, PVH229, NC71, K346, K326, and K394 were inoculated with six isolates of both complexes. The variables evaluated were the incidence and severity of the symptoms. The area under the disease progress curves (AUDPC) was calculated and subjected to analysis of variance (ANOVA). Also, disease epidemiological models were fitted to the experimental data. The MB47 variety was significantly less infected and the varieties K346, K326, and K394 had the highest AUDPC means, showing susceptibility to the isolates. The disease intensity curves were adequately described by the monomolecular and logistic models. The results provide, for the first time, information about the levels of tolerance to vascular wilt and root rot under controlled conditions for the main varieties of Virginia-type tobacco grown in NWA.
Highlights:
FOSC isolates produced mainly wilting, chlorosis, and growth reduction in tobacco plants; in contrast, FSSC isolates caused root rot, with characteristic necrotic lesions and root rot symptoms.
The highest DSI scores were registered for Fo27 and Fo15, while the lowest DSI score was found for Fs98.
The results obtained from the DSI scores were related to the mean AUDPC values of the isolates.
MB47 and NC71 were significantly less infected than the other varieties, which registered low AUDPC values.The production of tobacco (Nicotiana tabacum L.) in Argentina is centered in the northwestern region (NWA), where the incidence of root rots and stem diseases caused by Fusarium spp. has increased considerably in recent years. This study aimed to evaluate the pathogenicity levels of isolates of the F. oxysporum and F. solani complexes in different varieties of Virginia Type tobacco. The commercial varieties MB47, PVH229, NC71, K346, K326, and K394 were inoculated with six isolates of both complexes. The variables evaluated were the incidence and severity of the symptoms. The area under the disease progress curves (AUDPC) was calculated and subjected to analysis of variance (ANOVA). Also, disease epidemiological models were fitted to the experimental data. The MB47 variety was significantly less infected and the varieties K346, K326, and K394 had the highest AUDPC means, showing susceptibility to the isolates. The disease intensity curves were adequately described by the monomolecular and logistic models. The results provide, for the first time, information about the levels of tolerance to vascular wilt and root rot under controlled conditions for the main varieties of Virginia-type tobacco grown in NWA.
Highlights:
FOSC isolates produced mainly wilting, chlorosis, and growth reduction in tobacco plants; in contrast, FSSC isolates caused root rot, with characteristic necrotic lesions and root rot symptoms.
The highest DSI scores were registered for Fo27 and Fo15, while the lowest DSI score was found for Fs98.
The results obtained from the DSI scores were related to the mean AUDPC values of the isolates.
MB47 and NC71 were significantly less infected than the other varieties, which registered low AUDPC values
Key factors affecting the technical efficiency of bee farms in the province of La Pampa (Argentina): A two-stage DEA approach
Get PDFThis paper analyzes how decision-making, management capacity and technology adoption by beekeepers, affect the technical efficiency (TE) of Argentinean beekeeping through the case study of the province of La Pampa (Argentina). The assessment of TE is currently receiving ever-growing attention as an indicator of sustainability and usage of sufficient natural resources in beekeeping activities. This study aimed to identify the key factors affecting the technical efficiency of bee farms in the province of La Pampa. The study included a sample of 40 bee farms and estimated their TE score through an input-oriented Data Envelopment Analysis (DEA) model. In a second stage, Tobit regression was determined to evaluate the technical inefficiency determinants. This paper found that most beekeeping production units have low TE levels. Only 25 % of bee farms produce either at or close to the frontier. The Tobit model revealed that variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on pure technical efficiency. These results are considered to be of great interest for structured beekeeping systems on small-scale and family farms, as well as for political decision-makers, regarding a public program in apiculture.
Highlights:
Argentina is the leading country in America, exporting honey worldwide.
DEA approach and Tobit model based on a two-stage analysis is a useful tool when evaluating livestock production systems.
Bee farmers in La Pampa (Argentina) are operating below the production frontier, which indicates there is still scope for improvement.
Variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on technical efficiency.
Beekeepers should be encouraged by the government to improve their efficiency through training programs to ease decision-making and management, therefore enhancing productivity.This paper analyzes how decision-making, management capacity and technology adoption by beekeepers, affect the technical efficiency (TE) of Argentinean beekeeping through the case study of the province of La Pampa (Argentina). The assessment of TE is currently receiving ever-growing attention as an indicator of sustainability and usage of sufficient natural resources in beekeeping activities. This study aimed to identify the key factors affecting the technical efficiency of bee farms in the province of La Pampa. The study included a sample of 40 bee farms and estimated their TE score through an input-oriented Data Envelopment Analysis (DEA) model. In a second stage, Tobit regression was determined to evaluate the technical inefficiency determinants. This paper found that most beekeeping production units have low TE levels. Only 25 % of bee farms produce either at or close to the frontier. The Tobit model revealed that variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on pure technical efficiency. These results are considered to be of great interest for structured beekeeping systems on small-scale and family farms, as well as for political decision-makers, regarding a public program in apiculture.
Highlights:
Argentina is the leading country in America, exporting honey worldwide.
DEA approach and Tobit model based on a two-stage analysis is a useful tool when evaluating livestock production systems.
Bee farmers in La Pampa (Argentina) are operating below the production frontier, which indicates there is still scope for improvement.
Variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on technical efficiency.
Beekeepers should be encouraged by the government to improve their efficiency through training programs to ease decision-making and management, therefore enhancing productivity