Revista de la Facultad de Ciencias Agrarias
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Estudio comparativo del cariotipo en especies de Miltinea Ravenna, Phycella Lindl. y Rhodophiala C. Presl (Amaryllidaceae) de Chile
Get PDFLa familia Amaryllidaceae se encuentra distribuida en diversas regiones de Chile y Sudamérica. De los 11 géneros reconocidos por Ravenna, al menos tres de ellos presentan un reconocido potencial ornamental: Miltinea Ravenna, endémico de Chile y conformado por la especie Miltinea maulensis (Ravenna) Ravenna, Phycella Lindley, endémico de Chile, conformado por cuatro especies y distribuido desde el valle de Elqui hasta la altura de la región de Arauco y Rhodophiala C. Presl. presente en el sur de Brasil, Uruguay, Bolivia, Argentina y Chile conformado por un número aproximado de 40 especies. Actualmente, la información taxonómica tradicional para diferenciar los géneros presentes en Chile es insuficiente. Es por ello que se utilizó la citotaxonomía como una herramienta y fuente de evidencia taxonómica. El objetivo de esta investigación fue realizar un estudio comparativo de los cariotipos en representantes de tres géneros de Amaryllidaceae que crecen en Chile con el fin de ayudar a clarificar la posición taxonómica de ellos. Las especies analizadas fueron: Miltinea maulensis (Ravenna) Ravenna, Phycella australis Ravenna, Rhodophiala araucana (Phil.) Traub, Rhodophiala montana (Phil.) Traub, y Rhodophiala pratensis (Poepp.) Traub. Los resultados obtenidos indicaron que Miltinea maulensis y Phycella australis presentan características cariológicas muy similares, tanto en el número cromosómico, fórmula cariotípica e índices cromosómicos. Estas características permitirían considerar Miltinea como un sinónimo de Phycella. Por último, las tres especies de Rhodophiala analizadas comparten características citológicas muy similares, como por ejemplo, la presencia de una región NOR en el brazo largo del cromosoma 7, idéntico número cromosómico e índices de asimetría de los cariotipos casi iguales.La familia Amaryllidaceae se encuentra distribuida en diversas regiones de Chile y Sudamérica. De los 11 géneros reconocidos por Ravenna, al menos tres de ellos presentan un reconocido potencial ornamental: Miltinea Ravenna, endémico de Chile y conformado por la especie Miltinea maulensis (Ravenna) Ravenna, Phycella Lindley, endémico de Chile, conformado por cuatro especies y distribuido desde el valle de Elqui hasta la altura de la región de Arauco y Rhodophiala C. Presl. presente en el sur de Brasil, Uruguay, Bolivia, Argentina y Chile conformado por un número aproximado de 40 especies. Actualmente, la información taxonómica tradicional para diferenciar los géneros presentes en Chile es insuficiente. Es por ello que se utilizó la citotaxonomía como una herramienta y fuente de evidencia taxonómica. El objetivo de esta investigación fue realizar un estudio comparativo de los cariotipos en representantes de tres géneros de Amaryllidaceae que crecen en Chile con el fin de ayudar a clarificar la posición taxonómica de ellos. Las especies analizadas fueron: Miltinea maulensis (Ravenna) Ravenna, Phycella australis Ravenna, Rhodophiala araucana (Phil.) Traub, Rhodophiala montana (Phil.) Traub, y Rhodophiala pratensis (Poepp.) Traub. Los resultados obtenidos indicaron que Miltinea maulensis y Phycella australis presentan características cariológicas muy similares, tanto en el número cromosómico, fórmula cariotípica e índices cromosómicos. Estas características permitirían considerar Miltinea como un sinónimo de Phycella. Por último, las tres especies de Rhodophiala analizadas comparten características citológicas muy similares, como por ejemplo, la presencia de una región NOR en el brazo largo del cromosoma 7, idéntico número cromosómico e índices de asimetría de los cariotipos casi iguales
Pear and apple pomace compost as an alternative to commercial substrates in the production of tomato seedlings
No full textIt is important to look for alternative substrates to replace non-renewable resources such as peat used in growing media in horticulture. The aim of this work was to evaluate if the compost of pear and apple pomace could be used as an alternative to a commercial substrate for the production of tomato seedlings. Two experiments were carried out on trays with alveoli of 100 cm3 (experiment 1) and 30 cm3 (experiment 2). In experiment 1, three substrates were used: commercial substrate (CS), mixture of CS and pomace compost (CS+C) and pure compost (C). In experiment 2 a fourth treatment with a mixture of compost and perlite (C+P) was incorporated. The obtained results indicate that the development of the seedlings using CS+C and CS as a substrate was similar in cells of 100 cm3 and higher in cells of 30 cm3. In addition, the growth of seedlings on C+P in relation to CS showed similar or higher values in some variables. These results indicate that it would be feasible to replace the use of non-renewable resources such as peat in the production of tomato seedlings by a product obtained from a residue.
Tomato seedling growth was evaluated on trays with 100 cm3 alveoli and 30 cm3 alveoli on different substrates mixtures: commercial substrate (CS), mixture of CS and pomace compost (CS+C), pure compost (C) and mixture of compost and perlite (C+P).
Highlights
Seedling development using CS+C and CS as substrates was similar in cells of 100 cm3 and higher in cells of 30 cm3.
Seedling growth on C+P in relation to CS, showed similar or higher values for some variables such as root dry weight, shoot dry weight, stem diameter and shoot height.
In 30 cm3 cell trays of the compost and perlite treatment (3:1 v/v), obtained seedling quality would enable a high post-transplant survival percentage.
Pear and apple pomace compost may be an alternative to a commercial substrate containing peat for tomato seedlings production (Lycopersicon esculentum Mill.).It is important to look for alternative substrates to replace non-renewable resources such as peat used in growing media in horticulture. The aim of this work was to evaluate if the compost of pear and apple pomace could be used as an alternative to a commercial substrate for the production of tomato seedlings. Two experiments were carried out on trays with alveoli of 100 cm3 (experiment 1) and 30 cm3 (experiment 2). In experiment 1, three substrates were used: commercial substrate (CS), mixture of CS and pomace compost (CS+C) and pure compost (C). In experiment 2 a fourth treatment with a mixture of compost and perlite (C+P) was incorporated. The obtained results indicate that the development of the seedlings using CS+C and CS as a substrate was similar in cells of 100 cm3 and higher in cells of 30 cm3. In addition, the growth of seedlings on C+P in relation to CS showed similar or higher values in some variables. These results indicate that it would be feasible to replace the use of non-renewable resources such as peat in the production of tomato seedlings by a product obtained from a residue.
Highlights
Seedling development using CS+C and CS as substrates was similar in cells of 100 cm3 and higher in cells of 30 cm3.
Seedling growth on C+P in relation to CS, showed similar or higher values for some variables such as root dry weight, shoot dry weight, stem diameter and shoot height.
In 30 cm3 cell trays of the compost and perlite treatment (3:1 v/v), obtained seedling quality would enable a high post-transplant survival percentage.
Pear and apple pomace compost may be an alternative to a commercial substrate containing peat for tomato seedlings production (Lycopersicon esculentum Mill.)
Mycorrhizal fungi and phosphate fertilization in the production of Euterpe edulis seedlings
Get PDFThe present study evaluated the effect of arbuscular mycorrhizal fungi (AMF) inoculation on growth and nutrition of Euterpe edulis seedlings, supplemented or not with phosphate fertilization. The experiment was conducted in a greenhouse. The randomized block design, consisted of a 3x2 factorial arrangement and 4 replicates, with two phosphorus doses (0 and 50 mg dm-3 of soil), two microbiological treatments (Rhizophagus clarus; laroideoglomus etunicatum; R. clarus + C. etunicatum) and control (without fungus). Sowing and inoculation occurred concurrently in 2 kg plastic bags. Height, collar diameter, leaf area, dry shoot mass, macronutrient content and mycorrhizal colonization percentage were determined after 226 days. Regarding mycorrhizal colonization percentage, R. clarus resulted significantly beneficial for the production of E. edulis seedlings. In the absence of phosphate fertilization, R. clarus and mixed inoculum increased all biometric variables and macronutrient contents in seedlings. Therefore, it is concluded that AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy.
Highlights:
Rhizophagus clarus resulted significantly beneficial for the production of E. edulis seedlings and in the absence of phosphate fertilization, and mixed inoculum ( clarus + Claroideoglomus etunicatum) increased all biometric variables and macronutrient contents in seedlings.
The AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy.
The AMF, a biological agent of mutualistic associations with plants, constitutes an innovative approach to sustainable agriculture, contributing to increase plant survival rate, a key-factor for the successful reintroduction and conservation of E. edulis, as well as for its commercial exploitation.The present study evaluated the effect of arbuscular mycorrhizal fungi (AMF) inoculation on growth and nutrition of Euterpe edulis seedlings, supplemented or not with phosphate fertilization. The experiment was conducted in a greenhouse. The randomized block design, consisted of a 3x2 factorial arrangement and 4 replicates, with two phosphorus doses (0 and 50 mg dm-3 of soil), two microbiological treatments (Rhizophagus clarus; laroideoglomus etunicatum; R. clarus + C. etunicatum) and control (without fungus). Sowing and inoculation occurred concurrently in 2 kg plastic bags. Height, collar diameter, leaf area, dry shoot mass, macronutrient content and mycorrhizal colonization percentage were determined after 226 days. Regarding mycorrhizal colonization percentage, R. clarus resulted significantly beneficial for the production of E. edulis seedlings. In the absence of phosphate fertilization, R. clarus and mixed inoculum increased all biometric variables and macronutrient contents in seedlings. Therefore, it is concluded that AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy.
Highlights:
Rhizophagus clarus resulted significantly beneficial for the production of E. edulis seedlings and in the absence of phosphate fertilization, and mixed inoculum ( clarus + Claroideoglomus etunicatum) increased all biometric variables and macronutrient contents in seedlings.
The AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy.
The AMF, a biological agent of mutualistic associations with plants, constitutes an innovative approach to sustainable agriculture, contributing to increase plant survival rate, a key-factor for the successful reintroduction and conservation of E. edulis, as well as for its commercial exploitation.
Preliminary use of a fulvic acid, as a strategy to improve water use in saline soils: Preliminary use of a fulvic acid, as a strategy to improve water use in saline soils
No full textAn evaluation of a fulvic acid (FA) was made in a Loam soil, by selecting the best dose to achieve salt displacement under a drip emitter. In trial 1, PVC columns were filled with a loam soil and irrigated with a KCl solution of electrical conductivity (EC) of 12.5 dS m-1. Once the soil solution EC reached the value of the KCl solution, FA doses of 0, 2.1, 5.3 and 10.5 kg ha-1 were applied. The bulk electric conductivity and soil chemical properties were evaluated after 6 irrigation cycles. In trial 2, the same soil salinized with the KCl solution was placed in 0.8 m3 containers. Two irrigations treatments were performed: a control and the best FA dose from trial 1. The displacement of the salt bulb created from irrigation with a dropper in the soil profile was characterized. In trial 1, the dose of 5.3 kg ha-1 reached the lowest EC after the third irrigation. In trial 2, the selected dose reduced EC until 3.75 dS m-1 at 0.3 m depth at the third irrigation, saving 246 L of water compared to control. Additionally, the salinity bulbs were more horizontally extended in the FA treatment.
Highlights:
Application of FA (5.3 kg ha -1) reduced the water use by 50% compared to leaching carried out exclusively with water.
The use of Fulvic acid showed to be an alternative to consider in the recovery of saline soils under drip irrigation when irrigation water is scarce.
Little or not residual effect was found after the use of Fulvic acid.An evaluation of a fulvic acid (FA) was made in a Loam soil, by selecting the best dose to achieve salt displacement under a drip emitter. In trial 1, PVC columns were filled with a loam soil and irrigated with a KCl solution of electrical conductivity (EC) of 12.5 dS m-1. Once the soil solution EC reached the value of the KCl solution, FA doses of 0, 2.1, 5.3 and 10.5 kg ha-1 were applied. The bulk electric conductivity and soil chemical properties were evaluated after 6 irrigation cycles. In trial 2, the same soil salinized with the KCl solution was placed in 0.8 m3 containers. Two irrigations treatments were performed: a control and the best FA dose from trial 1. The displacement of the salt bulb created from irrigation with a dropper in the soil profile was characterized. In trial 1, the dose of 5.3 kg ha-1 reached the lowest EC after the third irrigation. In trial 2, the selected dose reduced EC until 3.75 dS m-1 at 0.3 m depth at the third irrigation, saving 246 L of water compared to control. Additionally, the salinity bulbs were more horizontally extended in the FA treatment.
Highlights:
Application of FA (5.3 kg ha -1) reduced the water use by 50% compared to leaching carried out exclusively with water.
The use of Fulvic acid showed to be an alternative to consider in the recovery of saline soils under drip irrigation when irrigation water is scarce.
Little or not residual effect was found after the use of Fulvic acid
Germination and development of M1 seedlings of two Selliera radicans Cav. accessions subjected to gamma radiation
Get PDFSelliera radicans is a creeping plant native to Chile, New Zealand and Australia. It is increasingly used in the ornamental industry, and there is interest in breeding it to create commercial varieties. The aim of this study was to determine the effects of different doses of gamma radiation applied to the seeds on the germination and development of seedlings (M1) and the LD50 of two accessions of Selliera radicans for use in the induction of mutations. Seeds of the Vichuquén and La Serena accessions were exposed to 0, 100, 200, 300, 400, 500, 600 and 700 Gy from a 60Co source. Weekly germination percentages along with seedling numbers and lengths were recorded. Vichuquén seeds were more sensitive to this physical agent. The LD50 was 243.9 Gy for Vichuquén and 445.6 Gy for La Serena. Seedling lengths reached almost 4 mm for Vichuquén and 11.3 mm for La Serena at 12 weeks after sowing. Doses lower than 200 Gy are recommended since higher doses do not allow the development of seedlings to the extended cotyledon stage.
Highlights:
This is the first radiosensitivity study for the Goodeniaceae family and therefore for the Selliera genus.
This study shows the specific effect of gamma radiation at the level of germination and seedling formation according to accession of origin.
This study could be used for the genetic improvement of Selliera radicans via the induction of mutations.Selliera radicans is a creeping plant native to Chile, New Zealand and Australia. It is increasingly used in the ornamental industry, and there is interest in breeding it to create commercial varieties. The aim of this study was to determine the effects of different doses of gamma radiation applied to the seeds on the germination and development of seedlings (M1) and the LD50 of two accessions of Selliera radicans for use in the induction of mutations. Seeds of the Vichuquén and La Serena accessions were exposed to 0, 100, 200, 300, 400, 500, 600 and 700 Gy from a 60Co source. Weekly germination percentages along with seedling numbers and lengths were recorded. Vichuquén seeds were more sensitive to this physical agent. The LD50 was 243.9 Gy for Vichuquén and 445.6 Gy for La Serena. Seedling lengths reached almost 4 mm for Vichuquén and 11.3 mm for La Serena at 12 weeks after sowing. Doses lower than 200 Gy are recommended since higher doses do not allow the development of seedlings to the extended cotyledon stage.
Highlights:
This is the first radiosensitivity study for the Goodeniaceae family and therefore for the Selliera genus.
This study shows the specific effect of gamma radiation at the level of germination and seedling formation according to accession of origin.
This study could be used for the genetic improvement of Selliera radicans via the induction of mutations
Collard greens and chicory intercropping efficiency as a function of chicory (Cichorium intybus) transplant time
Get PDFVegetable intercropping has advantages over single cultivation in terms of less environmental impact. However, to convince farmers to adopt this production system, it is necessary to prove greater efficiency in the production of more food per unit area and therefore an increase in productivity. An experiment was carried out aiming to evaluate the effect of the chicory transplant time in intercrops with collard greens on crop yields and land use efficiency index (LUE). The experimental design was a randomized block, with nine treatments in a 2 × 4 + 1 factorial scheme, and four replications. Crop systems (intercrop and monoculture) and chicory transplant time (0, 14, 28 and 42 days after transplant (DAT) of collard greens) were evaluated. The collard greens yield increased as the chicory transplant time was delayed. The total and per harvest yields of chicory were not influenced by its transplant time. Regardless of chicory transplant time, collard greens and chicory intercropping provided greater LUE than their monocultures and reached the maximum value (52% higher) when the chicory was transplanted 42 days after collard greens.
Highlights:
The collard green yield increased by 11 kg ha-1 for each day of delay in the chicory transplant (0 to 42 days).
The total and per harvest chicory yields were not influenced by its transplant time in relation to collard green transplant.
The collard green and chicory intercropping provided 52% higher land use efficiency than their monocultures when the chicory was transplanted 42 days after collard green.Vegetable intercropping has advantages over single cultivation in terms of less environmental impact. However, to convince farmers to adopt this production system, it is necessary to prove greater efficiency in the production of more food per unit area and therefore an increase in productivity. An experiment was carried out aiming to evaluate the effect of the chicory transplant time in intercrops with collard greens on crop yields and land use efficiency index (LUE). The experimental design was a randomized block, with nine treatments in a 2 × 4 + 1 factorial scheme, and four replications. Crop systems (intercrop and monoculture) and chicory transplant time (0, 14, 28 and 42 days after transplant (DAT) of collard greens) were evaluated. The collard greens yield increased as the chicory transplant time was delayed. The total and per harvest yields of chicory were not influenced by its transplant time. Regardless of chicory transplant time, collard greens and chicory intercropping provided greater LUE than their monocultures and reached the maximum value (52% higher) when the chicory was transplanted 42 days after collard greens.
Highlights:
The collard green yield increased by 11 kg ha-1 for each day of delay in the chicory transplant (0 to 42 days).
The total and per harvest chicory yields were not influenced by its transplant time in relation to collard green transplant.
The collard green and chicory intercropping provided 52% higher land use efficiency than their monocultures when the chicory was transplanted 42 days after collard green
Does foliar nicotinamide application affect second crop corn (Zea mays)?
Get PDFThe largest corn yeld in Brazil is currently in the second harvest, which is the most susceptible period to climatic adversities occurring during the cycle. Thus, introducing beneficial elements for maintaining the adequate development of the plant can help producers in obtaining greater kernel yields. Among studied elements, nicotinamide has potential use since it is associated with accumulating secondary metabolites and manifesting defence metabolism in plants. The objective of this work was to evaluate the influence of nicotinamide applied in different doses (only once or in instalments) on the biometric and productive characteristics of corn. The treatments were composed by the number of nicotinamide applications (one or two) and five doses (0, 50, 100, 150 and 200 mg L-1). Plant diameter, plant height, ear insertion height, leaf area and dry matter, yield and 100-kernel mass were evaluated. It was found that doses close to 100 mg L-1 resulted in increases in vegetative and reproductive development, regardless of the number of applications. In this way, foliar nicotinamide application positively influences the biometric and productive characteristics of second crop corn.
Highlights
The use of nicotinamide in corn plants improves its growth, yield components and grain yield.
A single application of nicotinamide during vegetative stage V3 at a dose of 100 mg L-1 is sufficient to increase the leaf area of corn plants.
Corn grain yield can be increased by 12.6% with a single application of nicotinamide.
There was no need for two applications of nicotinamide in corn crop.The largest corn yeld in Brazil is currently in the second harvest, which is the most susceptible period to climatic adversities occurring during the cycle. Thus, introducing beneficial elements for maintaining the adequate development of the plant can help producers in obtaining greater kernel yields. Among studied elements, nicotinamide has potential use since it is associated with accumulating secondary metabolites and manifesting defence metabolism in plants. The objective of this work was to evaluate the influence of nicotinamide applied in different doses (only once or in instalments) on the biometric and productive characteristics of corn. The treatments were composed by the number of nicotinamide applications (one or two) and five doses (0, 50, 100, 150 and 200 mg L-1). Plant diameter, plant height, ear insertion height, leaf area and dry matter, yield and 100-kernel mass were evaluated. It was found that doses close to 100 mg L-1 resulted in increases in vegetative and reproductive development, regardless of the number of applications. In this way, foliar nicotinamide application positively influences the biometric and productive characteristics of second crop corn.
Highlights
The use of nicotinamide in corn plants improves its growth, yield components and grain yield.
A single application of nicotinamide during vegetative stage V3 at a dose of 100 mg L-1 is sufficient to increase the leaf area of corn plants.
Corn grain yield can be increased by 12.6% with a single application of nicotinamide.
There was no need for two applications of nicotinamide in corn crop
Optimal plot size for experimentation of common beans (Phaseolus vulgaris L.) in the northern region of Minas Gerais, Brazil: Experimental plots
No full textThe objective was to evaluate the minimum size of experimental plots for the common bean (Phaseolus vulgaris L.) using the modified maximum curvature method. The experiment consisted of a uniformity trial with the cultivar BRSFC-402 sown at a spacing of 0.5 m between plant rows and 10 plants per meter within the row. 20 central rows measuring 20 m in length were considered for measurements, totaling 4,000 plants on an area of 200 m2. Final bean stand (FS), mean number of pods per plant (NPP), mean number of grain per pod (NGP), mean 100-grain weight (M100), and grain yield (kg ha-1) were evaluated. At evaluations, each row with 10 plants was considered a basic unit (0.5 m2), amounting to 400 basic units whose dimensions were combined into 14 plot shapes. The methods of relative information and modified maximum curvature were used to obtain the best shape and the most appropriate plot size, respectively, for experimental evaluation with common bean. Using these methods, and considering that the optimum plot should enable an efficient evaluation of all evaluated characteristics, the appropriate plot size was five UB (25 plants) in the format with five rows x one UB per row.
Highlights
Support for experimental evaluation of common beans under edaphoclimatic conditions in the northern region of Minas Gerais
Experimental plots with five basic units ensure maximum precision for joint evaluation of the main phenotypic descriptors of common beans.
The characteristics mass of 100 grains and productivity were associated with the smallest and the largest plot sizes, respectively.The objective was to evaluate the minimum size of experimental plots for the common bean (Phaseolus vulgaris L.) using the modified maximum curvature method. The experiment consisted of a uniformity trial with the cultivar BRSFC-402 sown at a spacing of 0.5 m between plant rows and 10 plants per meter within the row. 20 central rows measuring 20 m in length were considered for measurements, totaling 4,000 plants on an area of 200 m2. Final bean stand (FS), mean number of pods per plant (NPP), mean number of grain per pod (NGP), mean 100-grain weight (M100), and grain yield (kg ha-1) were evaluated. At evaluations, each row with 10 plants was considered a basic unit (0.5 m2), amounting to 400 basic units whose dimensions were combined into 14 plot shapes. The methods of relative information and modified maximum curvature were used to obtain the best shape and the most appropriate plot size, respectively, for experimental evaluation with common bean. Using these methods, and considering that the optimum plot should enable an efficient evaluation of all evaluated characteristics, the appropriate plot size was five UB (25 plants) in the format with five rows x one UB per row.
Highlights
Support for experimental evaluation of common beans under edaphoclimatic conditions in the northern region of Minas Gerais
Experimental plots with five basic units ensure maximum precision for joint evaluation of the main phenotypic descriptors of common beans.
The characteristics mass of 100 grains and productivity were associated with the smallest and the largest plot sizes, respectively
Modeling natural mortality for different plant densities in dendroenergetic trials
Get PDFMortality was modelled for three species (Acacia melanoxylon, Eucalyptus camaldulensis, Eucalyptus nitens) at three plantation densities (5000, 7500, and 10000 trees ha-1) in an trial of biomass production for purposes of dendroenergetic. One modelling based on individual tree level and two mortality modelling alternatives were evaluated: four survival probability equations and eight difference equations. The individual tree survival modelling considered a logistic model, is a linear combination of variables to individual tree at current time and the previous time as estimator, being the main variables the variation of the competition index and the variation of basal area growth between the current growth period and the previous growth period. The survival probability alternative used state variables of the stand (age, dominant height, average square diameter) as predictors, whereas the difference equations were adjusted according to age-based changes only. The models to stand levels showed better result than individual tree models, and in general, the mortality models based on difference equations presented better indicators of precision and parsimony. The rate of relative mortality was constant, i.e., (dN/dE)/N, and varied between species, revealing greater mortality, consecutively, in E. nitens, A. melanoxylon, and E. camaldulensis. Although mortality tended to be higher at greater plantation densities, stand density did not significantly affect the parameters of the adjusted models.
Highlights
The mortality stand level models showed better results than the individual tree models for dendroenergetic crops, and in general, the mortality models based on difference equations presented better precision indicators and parsimony.
The survival probability alternative involved state variables of the stand like age, dominant height, and average square diameter as predictors, while the difference equations were fitted according to age-based changes only.
Mortality tended to be higher at greater plantation densities, however stand density did not significantly affect the parameters of the mortality equations.Mortality was modelled for three species (Acacia melanoxylon, Eucalyptus camaldulensis, Eucalyptus nitens) at three plantation densities (5000, 7500, and 10000 trees ha-1) in an trial of biomass production for purposes of dendroenergetic. One modelling based on individual tree level and two mortality modelling alternatives were evaluated: four survival probability equations and eight difference equations. The individual tree survival modelling considered a logistic model, is a linear combination of variables to individual tree at current time and the previous time as estimator, being the main variables the variation of the competition index and the variation of basal area growth between the current growth period and the previous growth period. The survival probability alternative used state variables of the stand (age, dominant height, average square diameter) as predictors, whereas the difference equations were adjusted according to age-based changes only. The models to stand levels showed better result than individual tree models, and in general, the mortality models based on difference equations presented better indicators of precision and parsimony. The rate of relative mortality was constant, i.e., (dN/dE)/N, and varied between species, revealing greater mortality, consecutively, in E. nitens, A. melanoxylon, and E. camaldulensis. Although mortality tended to be higher at greater plantation densities, stand density did not significantly affect the parameters of the adjusted models.
Highlights
The mortality stand level models showed better results than the individual tree models for dendroenergetic crops, and in general, the mortality models based on difference equations presented better precision indicators and parsimony.
The survival probability alternative involved state variables of the stand like age, dominant height, and average square diameter as predictors, while the difference equations were fitted according to age-based changes only.
Mortality tended to be higher at greater plantation densities, however stand density did not significantly affect the parameters of the mortality equations
Anti-infective properties of medicinal plants from the Baja California peninsula, Mexico for the treatment of Fusarium oxysporum f. sp. basilici in organic sweet basil (Ocimum basilicum)
Get PDFCertified-organic farming systems in Baja California Peninsula and Northwest Mexico are nationally and globally recognized, especially due to the production of vegetables and aromatic herbs under protected agriculture systems. Based on the background of some species of the flora of Baja California Sur (BCS) to inhibit a diversity of microorganisms, the effect of 22 medicinal plants of the region was explored to know the in vitro activity against the fungus Fusarium oxysporum f. sp. basilici isolated from basil (Ocimum basilicum L.). The plants processed as crude ethanolic and aqueous extracts were analyzed in duplicate (three replicates) evaluating the inhibition of mycelial growth and spore germination. In mycelial inhibition test, all plants extracts (1000 mg L-1) showed an effectiveness of 11 to 40% to inhibit F. oxysporum. The most effective plant extracts according to 50% effective inhibition dose (ED50), were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with an ED50 of 220, 303 and 3000 mg L-1, respectively. Tukey’s PostHoc tests indicated that H. monogyra and L. tridentata are ten times (ED50 <300 mg L-1) more effective than L. palmeri (ED50 3000 mg L-1). In addition, the dose-response trend analyzes according to the logarithmic-logistic model (drc packages), showed the maximum slope values between 100 and 1000 mg L-1. In the spore germination inhibition tests, most ethanolic extracts (5000 mg L-1) showed an effectiveness between 21 and 80%. The results of this study demonstrated that the inhibitory potential of these plants used in BCS traditional medicine are a viable alternative for the control of F. oxysporum f. sp. basilici in organic basil production systems.
Highlights
22 medicinal native plants from the Baja California peninsula can effectively inhibit (in vitro) oxysporum f. sp. basilica.
The most effective species were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with a mycelial growth inhibition (ED50) of 220, 300 and 3000 mg L-1, respectively.
In vitro effectiveness of Fusarium-growth inhibition of medicinal plants of BCS were in ED50 ranges from 220 to 3000 mg L-1.
Creosote bush (L. tridentata) extract at a dose of 5000 mg L-1 can inhibit the fungal sporulation by up 80%.
The ethanol-aqueous extract of the medicinal plants of BCS have the potential to be used for long-term control of the fusariosis disease in basil.Certified-organic farming systems in Baja California Peninsula and Northwest Mexico are nationally and globally recognized, especially due to the production of vegetables and aromatic herbs under protected agriculture systems. Based on the background of some species of the flora of Baja California Sur (BCS) to inhibit a diversity of microorganisms, the effect of 22 medicinal plants of the region was explored to know the in vitro activity against the fungus Fusarium oxysporum f. sp. basilici isolated from basil (Ocimum basilicum L.). The plants processed as crude ethanolic and aqueous extracts were analyzed in duplicate (three replicates) evaluating the inhibition of mycelial growth and spore germination. In mycelial inhibition test, all plants extracts (1000 mg L-1) showed an effectiveness of 11 to 40% to inhibit F. oxysporum. The most effective plant extracts according to 50% effective inhibition dose (ED50), were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with an ED50 of 220, 303 and 3000 mg L-1, respectively. Tukey’s PostHoc tests indicated that H. monogyra and L. tridentata are ten times (ED50 <300 mg L-1) more effective than L. palmeri (ED50 3000 mg L-1). In addition, the dose-response trend analyzes according to the logarithmic-logistic model (drc packages), showed the maximum slope values between 100 and 1000 mg L-1. In the spore germination inhibition tests, most ethanolic extracts (5000 mg L-1) showed an effectiveness between 21 and 80%. The results of this study demonstrated that the inhibitory potential of these plants used in BCS traditional medicine are a viable alternative for the control of F. oxysporum f. sp. basilici in organic basil production systems.
Highlights
22 medicinal native plants from the Baja California peninsula can effectively inhibit (in vitro) oxysporum f. sp. basilica.
The most effective species were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with a mycelial growth inhibition (ED50) of 220, 300 and 3000 mg L-1, respectively.
In vitro effectiveness of Fusarium-growth inhibition of medicinal plants of BCS were in ED50 ranges from 220 to 3000 mg L-1.
Creosote bush (L. tridentata) extract at a dose of 5000 mg L-1 can inhibit the fungal sporulation by up 80%.
The ethanol-aqueous extract of the medicinal plants of BCS have the potential to be used for long-term control of the fusariosis disease in basil