This study highlights Adesmia pinifolia, a native high-Andean species, as a potential candidate f... more This study highlights Adesmia pinifolia, a native high-Andean species, as a potential candidate for the phytoremediation of soils contaminated with Cd and Hg. In this work, a semi-hydronic assay with different doses of Cd (3, 4.5, and 6 mg L -1 ) and Hg (0.8, 1.2, and 1.6 mg L -1 ) was analysed to evaluate the establishment of plants, antioxidant defence systems, oxidative stress, and the ability to accumulate heavy metals. The results indicate high survival rates (>80%); however, Cd significantly reduced shoot and root biomass, while Hg increased root biomass with the 1.6 mg L -1 treatment. Cd and Hg tend to accumulate more in roots (2534.24 µg/g and 596.4 µg g -1 , respectively) compared to shoots (398.53 µg g -1 and 140.8 µg g -1 , respectively). A significant decrease in the bioconcentration factor of Cd and Hg in roots was observed as metal levels increased, reaching the maximum value at 3 mg L -1 (805.59 ± 54.38) and 0.8 mg L -1 (804.54 ± 38.09). The translocation factor, <1 for both metals, suggests that translocation from roots to shoots is limited. An overproduction of reactive oxygen species (ROS) was observed, causing lipid peroxidation and oxidative damage to plant membranes. Tolerance strategies against subsequent toxicity indicate that enhanced glutathione reductase (GR) activity and glutathione (GSH) accumulation modulate Cd and Hg accumulation, toxicity, and tolerance.
Abstract An important concern for the expansion of olive production is related to the irrigation ... more Abstract An important concern for the expansion of olive production is related to the irrigation water availability. This study was driven on the hypothesis that regulated deficit irrigation (RDI) during spring - a period covering basically the fruit set, the seed development and the seed/pit hardening - does not affect significantly yield and chemical components from cv. Genovesa olive fruits. The objectives were twofold: a) to evaluate productive responses to RDI treatments, and b) to gain further information on the effect of irrigation on yield and chemical components from the constitutive parts of the olive fruit. To test the hypothesis, data of selected productive and quality parameters obtained from trees of three RDI treatments were tested and compared with those from full-irrigated trees. Results showed that over a 3-year period, water restriction had no effects on fruit pulp dry matter accumulation. Neither were significant effects on oil accumulation and fatty acid composition from both oil-bearing tissues (pulp and seed). Both tocopherols and total phenols (TP) from pulp were unchanged among RDI. Conversely, significant and opposite tendencies were noted for these parameters from the seeds: deficit irrigation caused lower amounts of α-tocopherol but higher TP than the full-irrigated treatment. Overall, results indicate that spring water restriction can save a significant amount of irrigation water with minor impact on important productive and quality parameters.
Seeds of two shrunken-2 (sh2) sweet corn (Zea mays L.) cultivars, Crisp N' Sweet 711 and How ... more Seeds of two shrunken-2 (sh2) sweet corn (Zea mays L.) cultivars, Crisp N' Sweet 711 and How Sweet It Is were used to analyze seed quality factor differences between the cultivars. Negative correlations occurred among germination percentage and imbibition, electric conductivity, potassium concentration and total soluble sugars of the seed leachate. Imbibition and total soluble sugar in the leachate significantly increased as imbibition temperature increased from 5°C to 25°C in both cultivars. A significant increase in conductivity of the leachate also occurred in `Crisp N' Sweet 711' when temperature increased. Cracks in the seed coat were more frequent in `How Sweet It Is' than `Crisp N' Sweet 711'. The higher concentrations of soluble sugars in the seed, greater imbibition rate, leakage conductivity, potassium and sugar concentration in the leachate may have been directly related to the poorer seed quality of `How Sweet It Is'. The alteration in cell me...
Atriplex nummularia is a potential species for restoration of areas affected by desertification p... more Atriplex nummularia is a potential species for restoration of areas affected by desertification processes and highly appraised for its value as forage. Its seeds present dormancy at the pericarp level. Scarification treatments were evaluated to eliminate pericarp. The fruits were soaked in concentrated sulfuric acid for 20, 30 or 45 minutes, or the pericarp was eliminated by thrashing or manually. The last two treatments eliminated completely the pericarp, but none of the chemical treatments removed it entirely. Seeds that after each of the chemical treatments were still completely covered by pericarp were additionally trashed as a new treatment. There was no germination in seeds with pericarp (control). Chemical treatments showed low germination percentages (5,0 to 7,5%) and rates due to their inefficacy in eliminating the pericarp. The highest germination percentages and rates were obtained in thrashed seeds without previous acid treatment (48%) and in seeds soaked in H 2 SO 4 for 30 minutes plus thrashing (45%). Eliminating pericarp manually or soaking in acid for 20 or 45 minutes plus thrashing resulted in lower germination rates and percentages.
Abstract The use of agrochemicals has revolutionized agricultural production, modifying the avail... more Abstract The use of agrochemicals has revolutionized agricultural production, modifying the availability of resources as nutrients, regulators, and biostimulants, modifying biotic relationships and physicochemical flows in agroecosystems. Nanoparticles (NPs) and nanomaterials (NMs) are a new class of physicochemical agents that promise to significantly improve the production capacity of agricultural systems. In this sense, it is crucial to understand the impacts that NPs and NMs can have in the short and medium term, on the different physical, chemical, and biological components of agroecosystems: soil, water, plants, the soil microbiome, and the plant itself. The understanding should emphasize the transfer of NPs and NMs in trophic chains, as well as to soil, water, and atmosphere. This chapter presents updated knowledge about the impact of NPs and NMs of essential and beneficial elements, metals, semimetals, and nonmetals, carbon, and zeolites on the different components of the agricultural ecological system. The content emphasizes the sustainability-focused balance that should exist between the pollution and trophic transfer vs. the positive impacts on crop productivity.
This study was aimed to evaluate the effect of regulated deficit irrigation (RDI), applied from m... more This study was aimed to evaluate the effect of regulated deficit irrigation (RDI), applied from mid-spring to early summer, on physiological parameters, vegetative growth and productivity in an intensive hedgerow olive orchard located in a non-traditional (marked winter-spring water-deficit) olive growing region. The experiments were carried out during three crop seasons by using four years old (7 m × 3.5 m) 'Genovesa' olive trees. Three RDI treatments (T25, T50 and T75) were applied as a percentage of crop evapotranspiration (25, 50 and 75% ETc, respectively) during the period from fruit set to pit hardening. Also, a control treatment was irrigated at 100% ETc during the whole crop season. Under the analyzed environmental conditions, stomatal conductance was less sensitive in young leaves than in mature leaves against changes in water availability. This fact should be considered when being used as benchmarks in olives trees submitted to water deprivation during periods with marked water constraint. Regarding vegetative parameters, significant reductions in apical vegetative shoot growth, trunk cross-sectional area and canopy volume were found in less irrigated treatments (T25 and T50) with respect to most irrigated ones (T75 and T100). Moreover, the strongest effects of deficit irrigation were observed when pruning was applied at the end of the second crop season evaluated. Both fruit and oil yields were barely affected by water availability. Although in the first crop season evaluated the fruit yield was greater in the full-irrigation treatmentwhich could be due to the age of the olive trees-, at the end of the whole experimental period (three crop years) the mean values from this yield component did not present significant differences among all irrigation treatments. Similarly, water availability did not affect oil yield (kg/ha); no significant differences were found among irrigation treatments in any of the crop seasons analyzed. The effects of water availability on productive parameters were more evident when analyzed as an estimated productive response; the total water productivity, calculated on both fruit weight and oil weight bases, gave the highest values in the most restrictive irrigation treatment. Overall, findings from this study could be of interest for olive cultivation in regions with dry spring period and for intensive hedgerow orchards suited to over-row harvesters. Imposing water restriction during this period could be suitable for achieving sustainable fruit and oil productivity while saving considerable amount of irrigation water. 100,000 ha)-warmed temperatures, minimal rainfalls, high evapotranspiration and intensifying water deficit take place during the winter
This paper aims to compare twelve strategic plans for the wine sector in three variables: start d... more This paper aims to compare twelve strategic plans for the wine sector in three variables: start date of the plan and time horizon; governance scope: territorial and thematic; content of the plan: objectives, proposed strategies and financing. The methodology is comparative. The non-probabilistic sample intentionally selected strategic plans from nine countries and the academic literature on them. The emphasis is put on synthesizing the different options or alternatives for strategic wine planning. The study aims to contribute to the state of the art on policies for development in general and for the wine sector in particular.
We tested the hypothesis that shrub canopies interact with monthly rain pulses to control litter ... more We tested the hypothesis that shrub canopies interact with monthly rain pulses to control litter decomposition in a sandy Monte desert, in Argentina. We assessed (i) the potential for litter decomposition of soils beneath the canopies of two dominant shrub species (Larrea divaricata and Bulnesia retama, Zygophyllaceae R. Br .) and from bare-ground microsites or 'openings'; (ii) litter decomposition at different spatial patches over the summer rainy season; and (iii) the interaction between vegetation patches and monthly rain pulses on shortterm litter decomposition, or decomposition pulses. In a greenhouse experiment, we found buried litter decomposition to be higher in soils from under the canopies of a dominant shrub species compared with soils from openings and sterilized controls. This, and higher nutrient concentration under shrub soils, suggest undercanopy soils may support a microbial community capable of decomposing litter at higher rates than soils in bare openings. However, field trials showed that shrub patches did not affect leaf litter decomposition over the rainy season, at least for short periods. We found an interaction between shrub patches and incubation time at the end of the field experiment, with higher litter decomposition rates under B. retama canopies. In a monthly field experiment, we found monthly rain pulses significantly explained decomposition pulses, irrespective of patch type. Our findings support the hypothesis that shrub soils have a greater potential for litter decomposition, but this is not directly translated to the field possibly due to interactions with abiotic factors. Rain pulses create conditions for decomposition pulses to occur at shorter time scales, whereas rainfall may interact with a dominant shrub undercanopy to control litter mass loss over longer time scales.
Journal of agricultural science & technology A, Oct 28, 2016
Salinity is a major stress that adversely affects growth and productivity in plants. There are sp... more Salinity is a major stress that adversely affects growth and productivity in plants. There are species that tolerate this stress within the genus Atriplex. Four species, A. lampa, A. crenatifolia, A. nummularia and A. argentina were compared for their ion accumulation and water relations under saline conditions. A greenhouse study was conducted by irrigating the four species with NaCl solutions at concentrations 0%, 1%, 2% and 4% starting when plants were six months old. Plants were harvested 45 d after starting the salinity treatments and analyzed for their ion contents. In the four Atriplex species, Na + and Clcontents in plants increased, while Ca 2+ and Mg 2+ decreased with the increase of salinity in the irrigation solution. The results suggested that A. argentina and A. nummularia were able to maintain a higher leaf relative water content (RWC) at low leaf water potential, which was associated with a greater capacity of osmotic adjustment. A. lampa showed lower ion accumulation and minor osmotic adjustment than the other species. It can be concluded that the accumulation of ions favors the lower osmotic potential and contributes to osmotic adjustment in these halophytes.
International Journal of Scientific & Technology Research, Aug 25, 2016
In the present study, we evaluated the effects of osmotic conditioning (priming) on seed germinat... more In the present study, we evaluated the effects of osmotic conditioning (priming) on seed germination and emergence rate index (ERI) of Panicum coloratum cv Klein Green, under optimal germination conditions (watered with distilled water) and salt stress (irrigated with different water potentials of NaCl solution). The seeds were primed in 3 osmotic solutions (NaCl, KCl, and K2SO4) during 2 days at 15°C. After the treatments the seed was germinated in 3 levels of salinity/osmotic potential media (12 μscm-1/-0,5 MPa; 30 μscm-1/-1,0 MPa; 43 μscm-1/-1,5 MPa). Salt stress conditions generate a depressive effect on the speed and germination percentage of Panicum coloratum seeds. Priming treatments increase significantly the germination percentage and ERI in prime seeds compared to untreated in non saline condition. At 12 μscm-1/-0,5 MPa salinity levels, the primed seeds showed higher significantly germination velocity (ERI) compared with non primed seeds.
Revista De La Facultad De Ciencias Agrarias, Sep 4, 2017
Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto d... more Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto del momento de cosecha sobre la calidad de semilla en dos cultivares de pimiento (Capsicum annuum) tipo cuatro cascos
The genus Adesmia (Fabaceae, Papilionoideae) is one of the scarce forage resources at high altitu... more The genus Adesmia (Fabaceae, Papilionoideae) is one of the scarce forage resources at high altitude and arid zones of South America. Its germination behavior has not been examined. Seeds of Adesmia subterranea "Cuerno de Cabra" were pretreated with sulfuric acid (1, 3, and 5 minutes soaking) and mechanical scarification to determine their impact upon dormancy and percentage and speed of germination. Treatments were evaluated under a range of constant temperatures (5 to 30° C) and 2 day/night cycles resembling the extreme environmental conditions of this species habitat. Water uptake and leachate conductivity were higher in the seeds scarified mechanically or with 5 minutes chemical scarification. These treatments also had the greatest total germination and rate at all temperatures in a petri dish germination test. However, in a cell tray experiment using a commercial substrate, the highest seedling emergence and rate were observed with chemical scarification (5 and 3 minutes). The high amount of leakage caused by the scarification affected emergence in a nonsterile media. The results indicate that A. subterranea seeds have an impermeable seed coat which restricts water uptake, and the efficiency of sulfuric acid scarification to overcome seed coat impermeability and improve germination and emergence.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Spanish Journal of Agricultural Research, Sep 1, 2004
The prickly pear Opuntia ficus-indica (L.) Mill. (family Cactaceae), a plant with crassulacean ac... more The prickly pear Opuntia ficus-indica (L.) Mill. (family Cactaceae), a plant with crassulacean acid metabolism (CAM), is mainly cultivated in hot, arid and semi-arid countries, including Tunisia,
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2019
Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliar... more Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliaris L. cultivars: Americana, Biloela and Texas 4464 Efecto del estrés por frío a nivel celular, foliar y capacidad de rebrote en tres cultivares de Cenchrus ciliaris L.: Americana,
Revista De La Facultad De Ciencias Agrarias, Feb 1, 2019
Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliar... more Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliaris L. cultivars: Americana, Biloela and Texas 4464 Efecto del estrés por frío a nivel celular, foliar y capacidad de rebrote en tres cultivares de Cenchrus ciliaris L.: Americana,
Revista De La Facultad De Ciencias Agrarias, Sep 4, 2017
Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto d... more Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto del momento de cosecha sobre la calidad de semilla en dos cultivares de pimiento (Capsicum annuum) tipo cuatro cascos
Seeds of Pistacia mutica, a potential rootstock for pistachio production, have poor germination a... more Seeds of Pistacia mutica, a potential rootstock for pistachio production, have poor germination and emergence due to seed endocarp impermeability. The objectives of this research were to evaluate the effect of chemical scarification with sulfuric acid on germination and emergence, to analyze the change in endocarp permeability of scarified seeds and to identify the best predictor of percentage and rate of emergence in field conditions. The chemical scarification increased significantly percentages and rates of emergence and germination compared to nontreated seeds. No statistical differences were observed among 2, 3, 4, and 5 hours of treatment. However, soaking seeds in sulfuric acid for five hours resulted in the highest germination percentage and rate, and the highest emergence percentage and rate were obtained in the seeds treated for 4 and 5 hours, respectively. The longer the scarification time the more increased the seed endocarp permeability and imbibition rate. This was the main cause of emergence and germination improvement in relation to the control. The reduction of seed weight during scarification was the best predictor of percentage and rate of emergence.
This study highlights Adesmia pinifolia, a native high-Andean species, as a potential candidate f... more This study highlights Adesmia pinifolia, a native high-Andean species, as a potential candidate for the phytoremediation of soils contaminated with Cd and Hg. In this work, a semi-hydronic assay with different doses of Cd (3, 4.5, and 6 mg L -1 ) and Hg (0.8, 1.2, and 1.6 mg L -1 ) was analysed to evaluate the establishment of plants, antioxidant defence systems, oxidative stress, and the ability to accumulate heavy metals. The results indicate high survival rates (>80%); however, Cd significantly reduced shoot and root biomass, while Hg increased root biomass with the 1.6 mg L -1 treatment. Cd and Hg tend to accumulate more in roots (2534.24 µg/g and 596.4 µg g -1 , respectively) compared to shoots (398.53 µg g -1 and 140.8 µg g -1 , respectively). A significant decrease in the bioconcentration factor of Cd and Hg in roots was observed as metal levels increased, reaching the maximum value at 3 mg L -1 (805.59 ± 54.38) and 0.8 mg L -1 (804.54 ± 38.09). The translocation factor, <1 for both metals, suggests that translocation from roots to shoots is limited. An overproduction of reactive oxygen species (ROS) was observed, causing lipid peroxidation and oxidative damage to plant membranes. Tolerance strategies against subsequent toxicity indicate that enhanced glutathione reductase (GR) activity and glutathione (GSH) accumulation modulate Cd and Hg accumulation, toxicity, and tolerance.
Abstract An important concern for the expansion of olive production is related to the irrigation ... more Abstract An important concern for the expansion of olive production is related to the irrigation water availability. This study was driven on the hypothesis that regulated deficit irrigation (RDI) during spring - a period covering basically the fruit set, the seed development and the seed/pit hardening - does not affect significantly yield and chemical components from cv. Genovesa olive fruits. The objectives were twofold: a) to evaluate productive responses to RDI treatments, and b) to gain further information on the effect of irrigation on yield and chemical components from the constitutive parts of the olive fruit. To test the hypothesis, data of selected productive and quality parameters obtained from trees of three RDI treatments were tested and compared with those from full-irrigated trees. Results showed that over a 3-year period, water restriction had no effects on fruit pulp dry matter accumulation. Neither were significant effects on oil accumulation and fatty acid composition from both oil-bearing tissues (pulp and seed). Both tocopherols and total phenols (TP) from pulp were unchanged among RDI. Conversely, significant and opposite tendencies were noted for these parameters from the seeds: deficit irrigation caused lower amounts of α-tocopherol but higher TP than the full-irrigated treatment. Overall, results indicate that spring water restriction can save a significant amount of irrigation water with minor impact on important productive and quality parameters.
Seeds of two shrunken-2 (sh2) sweet corn (Zea mays L.) cultivars, Crisp N' Sweet 711 and How ... more Seeds of two shrunken-2 (sh2) sweet corn (Zea mays L.) cultivars, Crisp N' Sweet 711 and How Sweet It Is were used to analyze seed quality factor differences between the cultivars. Negative correlations occurred among germination percentage and imbibition, electric conductivity, potassium concentration and total soluble sugars of the seed leachate. Imbibition and total soluble sugar in the leachate significantly increased as imbibition temperature increased from 5°C to 25°C in both cultivars. A significant increase in conductivity of the leachate also occurred in `Crisp N' Sweet 711' when temperature increased. Cracks in the seed coat were more frequent in `How Sweet It Is' than `Crisp N' Sweet 711'. The higher concentrations of soluble sugars in the seed, greater imbibition rate, leakage conductivity, potassium and sugar concentration in the leachate may have been directly related to the poorer seed quality of `How Sweet It Is'. The alteration in cell me...
Atriplex nummularia is a potential species for restoration of areas affected by desertification p... more Atriplex nummularia is a potential species for restoration of areas affected by desertification processes and highly appraised for its value as forage. Its seeds present dormancy at the pericarp level. Scarification treatments were evaluated to eliminate pericarp. The fruits were soaked in concentrated sulfuric acid for 20, 30 or 45 minutes, or the pericarp was eliminated by thrashing or manually. The last two treatments eliminated completely the pericarp, but none of the chemical treatments removed it entirely. Seeds that after each of the chemical treatments were still completely covered by pericarp were additionally trashed as a new treatment. There was no germination in seeds with pericarp (control). Chemical treatments showed low germination percentages (5,0 to 7,5%) and rates due to their inefficacy in eliminating the pericarp. The highest germination percentages and rates were obtained in thrashed seeds without previous acid treatment (48%) and in seeds soaked in H 2 SO 4 for 30 minutes plus thrashing (45%). Eliminating pericarp manually or soaking in acid for 20 or 45 minutes plus thrashing resulted in lower germination rates and percentages.
Abstract The use of agrochemicals has revolutionized agricultural production, modifying the avail... more Abstract The use of agrochemicals has revolutionized agricultural production, modifying the availability of resources as nutrients, regulators, and biostimulants, modifying biotic relationships and physicochemical flows in agroecosystems. Nanoparticles (NPs) and nanomaterials (NMs) are a new class of physicochemical agents that promise to significantly improve the production capacity of agricultural systems. In this sense, it is crucial to understand the impacts that NPs and NMs can have in the short and medium term, on the different physical, chemical, and biological components of agroecosystems: soil, water, plants, the soil microbiome, and the plant itself. The understanding should emphasize the transfer of NPs and NMs in trophic chains, as well as to soil, water, and atmosphere. This chapter presents updated knowledge about the impact of NPs and NMs of essential and beneficial elements, metals, semimetals, and nonmetals, carbon, and zeolites on the different components of the agricultural ecological system. The content emphasizes the sustainability-focused balance that should exist between the pollution and trophic transfer vs. the positive impacts on crop productivity.
This study was aimed to evaluate the effect of regulated deficit irrigation (RDI), applied from m... more This study was aimed to evaluate the effect of regulated deficit irrigation (RDI), applied from mid-spring to early summer, on physiological parameters, vegetative growth and productivity in an intensive hedgerow olive orchard located in a non-traditional (marked winter-spring water-deficit) olive growing region. The experiments were carried out during three crop seasons by using four years old (7 m × 3.5 m) 'Genovesa' olive trees. Three RDI treatments (T25, T50 and T75) were applied as a percentage of crop evapotranspiration (25, 50 and 75% ETc, respectively) during the period from fruit set to pit hardening. Also, a control treatment was irrigated at 100% ETc during the whole crop season. Under the analyzed environmental conditions, stomatal conductance was less sensitive in young leaves than in mature leaves against changes in water availability. This fact should be considered when being used as benchmarks in olives trees submitted to water deprivation during periods with marked water constraint. Regarding vegetative parameters, significant reductions in apical vegetative shoot growth, trunk cross-sectional area and canopy volume were found in less irrigated treatments (T25 and T50) with respect to most irrigated ones (T75 and T100). Moreover, the strongest effects of deficit irrigation were observed when pruning was applied at the end of the second crop season evaluated. Both fruit and oil yields were barely affected by water availability. Although in the first crop season evaluated the fruit yield was greater in the full-irrigation treatmentwhich could be due to the age of the olive trees-, at the end of the whole experimental period (three crop years) the mean values from this yield component did not present significant differences among all irrigation treatments. Similarly, water availability did not affect oil yield (kg/ha); no significant differences were found among irrigation treatments in any of the crop seasons analyzed. The effects of water availability on productive parameters were more evident when analyzed as an estimated productive response; the total water productivity, calculated on both fruit weight and oil weight bases, gave the highest values in the most restrictive irrigation treatment. Overall, findings from this study could be of interest for olive cultivation in regions with dry spring period and for intensive hedgerow orchards suited to over-row harvesters. Imposing water restriction during this period could be suitable for achieving sustainable fruit and oil productivity while saving considerable amount of irrigation water. 100,000 ha)-warmed temperatures, minimal rainfalls, high evapotranspiration and intensifying water deficit take place during the winter
This paper aims to compare twelve strategic plans for the wine sector in three variables: start d... more This paper aims to compare twelve strategic plans for the wine sector in three variables: start date of the plan and time horizon; governance scope: territorial and thematic; content of the plan: objectives, proposed strategies and financing. The methodology is comparative. The non-probabilistic sample intentionally selected strategic plans from nine countries and the academic literature on them. The emphasis is put on synthesizing the different options or alternatives for strategic wine planning. The study aims to contribute to the state of the art on policies for development in general and for the wine sector in particular.
We tested the hypothesis that shrub canopies interact with monthly rain pulses to control litter ... more We tested the hypothesis that shrub canopies interact with monthly rain pulses to control litter decomposition in a sandy Monte desert, in Argentina. We assessed (i) the potential for litter decomposition of soils beneath the canopies of two dominant shrub species (Larrea divaricata and Bulnesia retama, Zygophyllaceae R. Br .) and from bare-ground microsites or 'openings'; (ii) litter decomposition at different spatial patches over the summer rainy season; and (iii) the interaction between vegetation patches and monthly rain pulses on shortterm litter decomposition, or decomposition pulses. In a greenhouse experiment, we found buried litter decomposition to be higher in soils from under the canopies of a dominant shrub species compared with soils from openings and sterilized controls. This, and higher nutrient concentration under shrub soils, suggest undercanopy soils may support a microbial community capable of decomposing litter at higher rates than soils in bare openings. However, field trials showed that shrub patches did not affect leaf litter decomposition over the rainy season, at least for short periods. We found an interaction between shrub patches and incubation time at the end of the field experiment, with higher litter decomposition rates under B. retama canopies. In a monthly field experiment, we found monthly rain pulses significantly explained decomposition pulses, irrespective of patch type. Our findings support the hypothesis that shrub soils have a greater potential for litter decomposition, but this is not directly translated to the field possibly due to interactions with abiotic factors. Rain pulses create conditions for decomposition pulses to occur at shorter time scales, whereas rainfall may interact with a dominant shrub undercanopy to control litter mass loss over longer time scales.
Journal of agricultural science & technology A, Oct 28, 2016
Salinity is a major stress that adversely affects growth and productivity in plants. There are sp... more Salinity is a major stress that adversely affects growth and productivity in plants. There are species that tolerate this stress within the genus Atriplex. Four species, A. lampa, A. crenatifolia, A. nummularia and A. argentina were compared for their ion accumulation and water relations under saline conditions. A greenhouse study was conducted by irrigating the four species with NaCl solutions at concentrations 0%, 1%, 2% and 4% starting when plants were six months old. Plants were harvested 45 d after starting the salinity treatments and analyzed for their ion contents. In the four Atriplex species, Na + and Clcontents in plants increased, while Ca 2+ and Mg 2+ decreased with the increase of salinity in the irrigation solution. The results suggested that A. argentina and A. nummularia were able to maintain a higher leaf relative water content (RWC) at low leaf water potential, which was associated with a greater capacity of osmotic adjustment. A. lampa showed lower ion accumulation and minor osmotic adjustment than the other species. It can be concluded that the accumulation of ions favors the lower osmotic potential and contributes to osmotic adjustment in these halophytes.
International Journal of Scientific & Technology Research, Aug 25, 2016
In the present study, we evaluated the effects of osmotic conditioning (priming) on seed germinat... more In the present study, we evaluated the effects of osmotic conditioning (priming) on seed germination and emergence rate index (ERI) of Panicum coloratum cv Klein Green, under optimal germination conditions (watered with distilled water) and salt stress (irrigated with different water potentials of NaCl solution). The seeds were primed in 3 osmotic solutions (NaCl, KCl, and K2SO4) during 2 days at 15°C. After the treatments the seed was germinated in 3 levels of salinity/osmotic potential media (12 μscm-1/-0,5 MPa; 30 μscm-1/-1,0 MPa; 43 μscm-1/-1,5 MPa). Salt stress conditions generate a depressive effect on the speed and germination percentage of Panicum coloratum seeds. Priming treatments increase significantly the germination percentage and ERI in prime seeds compared to untreated in non saline condition. At 12 μscm-1/-0,5 MPa salinity levels, the primed seeds showed higher significantly germination velocity (ERI) compared with non primed seeds.
Revista De La Facultad De Ciencias Agrarias, Sep 4, 2017
Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto d... more Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto del momento de cosecha sobre la calidad de semilla en dos cultivares de pimiento (Capsicum annuum) tipo cuatro cascos
The genus Adesmia (Fabaceae, Papilionoideae) is one of the scarce forage resources at high altitu... more The genus Adesmia (Fabaceae, Papilionoideae) is one of the scarce forage resources at high altitude and arid zones of South America. Its germination behavior has not been examined. Seeds of Adesmia subterranea "Cuerno de Cabra" were pretreated with sulfuric acid (1, 3, and 5 minutes soaking) and mechanical scarification to determine their impact upon dormancy and percentage and speed of germination. Treatments were evaluated under a range of constant temperatures (5 to 30° C) and 2 day/night cycles resembling the extreme environmental conditions of this species habitat. Water uptake and leachate conductivity were higher in the seeds scarified mechanically or with 5 minutes chemical scarification. These treatments also had the greatest total germination and rate at all temperatures in a petri dish germination test. However, in a cell tray experiment using a commercial substrate, the highest seedling emergence and rate were observed with chemical scarification (5 and 3 minutes). The high amount of leakage caused by the scarification affected emergence in a nonsterile media. The results indicate that A. subterranea seeds have an impermeable seed coat which restricts water uptake, and the efficiency of sulfuric acid scarification to overcome seed coat impermeability and improve germination and emergence.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Spanish Journal of Agricultural Research, Sep 1, 2004
The prickly pear Opuntia ficus-indica (L.) Mill. (family Cactaceae), a plant with crassulacean ac... more The prickly pear Opuntia ficus-indica (L.) Mill. (family Cactaceae), a plant with crassulacean acid metabolism (CAM), is mainly cultivated in hot, arid and semi-arid countries, including Tunisia,
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2019
Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliar... more Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliaris L. cultivars: Americana, Biloela and Texas 4464 Efecto del estrés por frío a nivel celular, foliar y capacidad de rebrote en tres cultivares de Cenchrus ciliaris L.: Americana,
Revista De La Facultad De Ciencias Agrarias, Feb 1, 2019
Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliar... more Effect of cold stress at cellular and foliar level and regrowth capacity of three Cenchrus ciliaris L. cultivars: Americana, Biloela and Texas 4464 Efecto del estrés por frío a nivel celular, foliar y capacidad de rebrote en tres cultivares de Cenchrus ciliaris L.: Americana,
Revista De La Facultad De Ciencias Agrarias, Sep 4, 2017
Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto d... more Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum) Efecto del momento de cosecha sobre la calidad de semilla en dos cultivares de pimiento (Capsicum annuum) tipo cuatro cascos
Seeds of Pistacia mutica, a potential rootstock for pistachio production, have poor germination a... more Seeds of Pistacia mutica, a potential rootstock for pistachio production, have poor germination and emergence due to seed endocarp impermeability. The objectives of this research were to evaluate the effect of chemical scarification with sulfuric acid on germination and emergence, to analyze the change in endocarp permeability of scarified seeds and to identify the best predictor of percentage and rate of emergence in field conditions. The chemical scarification increased significantly percentages and rates of emergence and germination compared to nontreated seeds. No statistical differences were observed among 2, 3, 4, and 5 hours of treatment. However, soaking seeds in sulfuric acid for five hours resulted in the highest germination percentage and rate, and the highest emergence percentage and rate were obtained in the seeds treated for 4 and 5 hours, respectively. The longer the scarification time the more increased the seed endocarp permeability and imbibition rate. This was the main cause of emergence and germination improvement in relation to the control. The reduction of seed weight during scarification was the best predictor of percentage and rate of emergence.
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