cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.20011289
title: Ammonia volatilization from nitrogen fertilizers applied to sugarcane straw

description: ABSTRACT Maintenance of crop residues over soil surface under conservational systems limits incorporation of nitrogen fertilizers into the soil. Application of urea over crop residues enhance N-NH3 volatilization losses, justifying the usage of urease inhibitors or N sources less susceptible to volatilization under such conditions. This study aimed to evaluate volatilization losses from N sources applied over sugarcane straw. A field trial was carried out in a sugarcane field in Iracemapolis, Sao Paulo on a Typic Kandiudox in June 2014. We used a complete block experimental design, with seven treatments and four replications. Treatments included Control [CO], ammonium nitrate [AN], NS30TM (ammonium nitrate-75% and ammonium sulfate-25% fused mixture) [NS30TM], ammonium nitrate plus ammonium sulfate (ammonium nitrate-75% and ammonium sulfate-25% physical mixture) [AN-AS], urea [UR], urea treated with 0.4% Cu and 0.15% B [UR-CuB], urea treated with 530 mg kg-1 of NBPT [UR-NBPT]. Treatments were applied at rate of 100 kg ha-1 N (except CO). Volatilization losses were quantified up to 30 days after fertilization (DAF). Maximum N-NH3 occurred 16 DAF for UR and UR-CuB and 20 DAF for UR-NBPT. Accumulated N-NH3 losses ranged from 20% (UR), 17% (UR-CuB), and 14% (UR-NBPT) of applied N; non-amidic sources showed losses lower than 1%. Adding urease inhibitor to urea shows potential in reducing volatilization losses even under application over large amounts of straw.
DOI: 10.6084/m9.figshare.20011289.v1
title: Ammonia volatilization from nitrogen fertilizers applied to sugarcane straw

description: ABSTRACT Maintenance of crop residues over soil surface under conservational systems limits incorporation of nitrogen fertilizers into the soil. Application of urea over crop residues enhance N-NH3 volatilization losses, justifying the usage of urease inhibitors or N sources less susceptible to volatilization under such conditions. This study aimed to evaluate volatilization losses from N sources applied over sugarcane straw. A field trial was carried out in a sugarcane field in Iracemapolis, Sao Paulo on a Typic Kandiudox in June 2014. We used a complete block experimental design, with seven treatments and four replications. Treatments included Control [CO], ammonium nitrate [AN], NS30TM (ammonium nitrate-75% and ammonium sulfate-25% fused mixture) [NS30TM], ammonium nitrate plus ammonium sulfate (ammonium nitrate-75% and ammonium sulfate-25% physical mixture) [AN-AS], urea [UR], urea treated with 0.4% Cu and 0.15% B [UR-CuB], urea treated with 530 mg kg-1 of NBPT [UR-NBPT]. Treatments were applied at rate of 100 kg ha-1 N (except CO). Volatilization losses were quantified up to 30 days after fertilization (DAF). Maximum N-NH3 occurred 16 DAF for UR and UR-CuB and 20 DAF for UR-NBPT. Accumulated N-NH3 losses ranged from 20% (UR), 17% (UR-CuB), and 14% (UR-NBPT) of applied N; non-amidic sources showed losses lower than 1%. Adding urease inhibitor to urea shows potential in reducing volatilization losses even under application over large amounts of straw.
DOI: 10.6084/m9.figshare.20011291
title: Interference from the vertical variation of soil phosphorus and from water stress on growth in maize, the soybean and sunflower

description: ABSTRACT The distribution of phosphorus (P) in the soil interferes with the availability of the nutrient and can affect plant growth. The aim of this study was to compare the growth and accumulation of P in maize, soybean and sunflower plants in vertical gradients of the nutrient in the soil, with and without water stress. The design was completely randomised with five replications, in a 3 x 2 factorial scheme: three soil depth gradients of P (decreasing, increasing and nil) and two conditions of soil water availability (with and with no water stress). The depth gradients of P were in decreasing doses of P2O5 (300, 200, 100 and 0 mg dm-3), increasing doses (0, 100, 200 and 300 mg dm-3) and equal doses (150 mg dm-3) applied to the intermediate layers between 0.0-5.0, 5.1-10.0, 10.1-15.0 and 15.1-20.0 cm. Height, dry weight and P accumulation in the roots and shoots were quantified. The data were submitted to analysis of variance, and mean values compared by Tukey's test (p&lt;0.05). The distribution of P in the soil did not interfere with growth or nutrient accumulation in the soybean. Phosphate fertiliser located in the surface or subsurface layers favoured greater growth and the accumulation of P in the maize and sunflower, compared to the uniform distribution of the nutrient in the 0-20 cm layer. The increase in phosphate fertiliser at depth did not increase growth or P accumulation in the three crops, even under conditions of water stress.
DOI: 10.6084/m9.figshare.20011291.v1
title: Interference from the vertical variation of soil phosphorus and from water stress on growth in maize, the soybean and sunflower

description: ABSTRACT The distribution of phosphorus (P) in the soil interferes with the availability of the nutrient and can affect plant growth. The aim of this study was to compare the growth and accumulation of P in maize, soybean and sunflower plants in vertical gradients of the nutrient in the soil, with and without water stress. The design was completely randomised with five replications, in a 3 x 2 factorial scheme: three soil depth gradients of P (decreasing, increasing and nil) and two conditions of soil water availability (with and with no water stress). The depth gradients of P were in decreasing doses of P2O5 (300, 200, 100 and 0 mg dm-3), increasing doses (0, 100, 200 and 300 mg dm-3) and equal doses (150 mg dm-3) applied to the intermediate layers between 0.0-5.0, 5.1-10.0, 10.1-15.0 and 15.1-20.0 cm. Height, dry weight and P accumulation in the roots and shoots were quantified. The data were submitted to analysis of variance, and mean values compared by Tukey's test (p&lt;0.05). The distribution of P in the soil did not interfere with growth or nutrient accumulation in the soybean. Phosphate fertiliser located in the surface or subsurface layers favoured greater growth and the accumulation of P in the maize and sunflower, compared to the uniform distribution of the nutrient in the 0-20 cm layer. The increase in phosphate fertiliser at depth did not increase growth or P accumulation in the three crops, even under conditions of water stress.
DOI: 10.6084/m9.figshare.20011292
title: Mathematical modelling of thin-layer drying in peanut fruit

description: ABSTRACT The aim of this study was to fit mathematical models to the experimental data from the thin-layer drying of peanut fruit subjected to different drying-air temperatures. Peanut fruit from the IAC 505 cultivar were used. The peanut fruit were subjected to drying in a forced ventilation oven at different temperature levels (40, 50, 60 and 70 ºC). Ten mathematical models, traditionally used to represent the kinetics of thin-layer drying, were fit to the experimental data. Based on the results, it can be concluded that among the models adjusted to the experimental data, the Page model was chosen to represent the phenomenon of thin-layer drying in peanut fruit. The effective diffusion coefficient increases with the rise in temperature, and its relation to the drying temperature can be described by the Arrhenius equation. The values for the thermodynamic properties, enthalpy and entropy, were reduced with the increasing temperature of the drying air, while the values for Gibbs free energy increased with the increase in temperature.
DOI: 10.6084/m9.figshare.20011292.v1
title: Mathematical modelling of thin-layer drying in peanut fruit

description: ABSTRACT The aim of this study was to fit mathematical models to the experimental data from the thin-layer drying of peanut fruit subjected to different drying-air temperatures. Peanut fruit from the IAC 505 cultivar were used. The peanut fruit were subjected to drying in a forced ventilation oven at different temperature levels (40, 50, 60 and 70 ºC). Ten mathematical models, traditionally used to represent the kinetics of thin-layer drying, were fit to the experimental data. Based on the results, it can be concluded that among the models adjusted to the experimental data, the Page model was chosen to represent the phenomenon of thin-layer drying in peanut fruit. The effective diffusion coefficient increases with the rise in temperature, and its relation to the drying temperature can be described by the Arrhenius equation. The values for the thermodynamic properties, enthalpy and entropy, were reduced with the increasing temperature of the drying air, while the values for Gibbs free energy increased with the increase in temperature.
DOI: 10.6084/m9.figshare.20011294
title: Quality of base cutting in sugarcane using knives of different angles and coatings

description: ABSTRACT Mechanisation of the sugarcane harvest has been on the increase in those states where sugarcane is produced, because of the need to eradicate pre-harvest burning throughout the area of sugarcane plantation by 2017. However, the base cutting system of the harvesters is still proving inefficient, directly interfering in the quality of the raw material and compromising the life of the plantation. The aim of this study therefore, was to evaluate the indices for damage and loss in ratoon sugarcane, for three types of knife used in base cutting in harvesters, using two knives coated with tungsten carbide and another uncoated, all at different angles. The experimental design was completely randomised into bands, with the number of replications defined as a function of the time and mode of use of the knives. The variables cutting height and the indices of damage and loss in the ratoon cane were used as quality indicators. The indices of damage and loss are influenced by the type of knife used. From the indices of damage and loss in the ratoon cane, the highest operating quality is seen with coated knives at an angle of 13º.
DOI: 10.6084/m9.figshare.20011294.v1
title: Quality of base cutting in sugarcane using knives of different angles and coatings

description: ABSTRACT Mechanisation of the sugarcane harvest has been on the increase in those states where sugarcane is produced, because of the need to eradicate pre-harvest burning throughout the area of sugarcane plantation by 2017. However, the base cutting system of the harvesters is still proving inefficient, directly interfering in the quality of the raw material and compromising the life of the plantation. The aim of this study therefore, was to evaluate the indices for damage and loss in ratoon sugarcane, for three types of knife used in base cutting in harvesters, using two knives coated with tungsten carbide and another uncoated, all at different angles. The experimental design was completely randomised into bands, with the number of replications defined as a function of the time and mode of use of the knives. The variables cutting height and the indices of damage and loss in the ratoon cane were used as quality indicators. The indices of damage and loss are influenced by the type of knife used. From the indices of damage and loss in the ratoon cane, the highest operating quality is seen with coated knives at an angle of 13º.
DOI: 10.6084/m9.figshare.20011298
title: Physiological potential of Oryza sativa seeds treated with growth regulators at low temperatures

description: ABSTRACT The rapid and uniform establishment of rice crops is important for improving production. However, this condition is influenced by several factors, including the soil temperature when planting, which may delay seed germination and compromise the final stand. The aim of this study was to evaluate the behaviour of substances which have the effect of growth regulator when applied to the seeds of different rice cultivars under low-temperature conditions. The experiment was carried out in a completely randomised design with four replications in a bi-factorial scheme, where factor A was represented by the different products (gibberellic acid - AG3, tiamethoxam - TMX, Haf Plus® - HAF, and a control with water - TEST), and factor B by the irrigated rice cultivars (IRGA 424, IRGA 425, Puitá INTA CL, and Avaxi CL). In addition, the experiment was repeated at temperatures of 17 °C and 25 °C in order to simulate low-temperature conditions. The results showed that AG3 is effective in increasing seed vigour in the rice cultivars at both temperatures, with the AG3, TMX and HAF responsible for increasing germination percentage only at the temperature of 17 °C. The effect of the products is more pronounced at low temperatures, and is dependent on the cultivar; in cultivars which are sensitive to cold there is no effect from the products used.
DOI: 10.6084/m9.figshare.20011298.v1
title: Physiological potential of Oryza sativa seeds treated with growth regulators at low temperatures

description: ABSTRACT The rapid and uniform establishment of rice crops is important for improving production. However, this condition is influenced by several factors, including the soil temperature when planting, which may delay seed germination and compromise the final stand. The aim of this study was to evaluate the behaviour of substances which have the effect of growth regulator when applied to the seeds of different rice cultivars under low-temperature conditions. The experiment was carried out in a completely randomised design with four replications in a bi-factorial scheme, where factor A was represented by the different products (gibberellic acid - AG3, tiamethoxam - TMX, Haf Plus® - HAF, and a control with water - TEST), and factor B by the irrigated rice cultivars (IRGA 424, IRGA 425, Puitá INTA CL, and Avaxi CL). In addition, the experiment was repeated at temperatures of 17 °C and 25 °C in order to simulate low-temperature conditions. The results showed that AG3 is effective in increasing seed vigour in the rice cultivars at both temperatures, with the AG3, TMX and HAF responsible for increasing germination percentage only at the temperature of 17 °C. The effect of the products is more pronounced at low temperatures, and is dependent on the cultivar; in cultivars which are sensitive to cold there is no effect from the products used.
DOI: 10.6084/m9.figshare.20011300
title: Reproductive ecology of the catfish, Hassar affinis (ACTINOPTERYGII: DORADIDAE), in three lakes of the Pindaré-Mearim Lake System, Maranhão

description: ABSTRACT Reproductive biology affords fundamental features for the establishment of protective measures for fish. The aim of the present work therefore was to determine the reproductive features of the catfish, Hassar affinis, known locally as bico-de-flor, in three lakes of the Pindaré-Mearim Lake System, in the state of Maranhão, with the aim of subsidising the closed season. Monthly collections were carried out between July 2014 and July 2015, when 206 individuals were sampled from Lake Aquiri (LA), 247 from Lake Cajari (LC), and 126 from Lake Viana (LV). In the laboratory, each individual was weighed and measured; a ventral longitudinal incision was then made in order to observe the gonads macroscopically. They were then fixed in Bouin's solution for microscopic analysis and in Gilson's solution for an analysis of fecundity. Positive allometry was recorded at the three study sites. The sex ratio for the total period was 3.29F:1M (LA), 2.43F:1M (LC) and 2.15F:1M (LV). Mean length at first sexual maturity was estimated at 10.60 cm (LA), 10.84 cm (LC) and 11.12 cm (LV). The period from March to May was defined as the breeding season for this species in the three lakes. Mean absolute fecundity was 21,634 oocytes (LA), 16,357 oocytes (LC) and 25,898 oocytes (LV). The information obtained through this study indicates that, in addition to being important spawning areas, the three lakes are interconnected in relation to the migratory dynamics of H. affinis, so it is necessary to arrive at a model that would satisfactorily cover the three lakes, considering that the dam has a negative effect on Lake Viana.
DOI: 10.6084/m9.figshare.20011300.v1
title: Reproductive ecology of the catfish, Hassar affinis (ACTINOPTERYGII: DORADIDAE), in three lakes of the Pindaré-Mearim Lake System, Maranhão

description: ABSTRACT Reproductive biology affords fundamental features for the establishment of protective measures for fish. The aim of the present work therefore was to determine the reproductive features of the catfish, Hassar affinis, known locally as bico-de-flor, in three lakes of the Pindaré-Mearim Lake System, in the state of Maranhão, with the aim of subsidising the closed season. Monthly collections were carried out between July 2014 and July 2015, when 206 individuals were sampled from Lake Aquiri (LA), 247 from Lake Cajari (LC), and 126 from Lake Viana (LV). In the laboratory, each individual was weighed and measured; a ventral longitudinal incision was then made in order to observe the gonads macroscopically. They were then fixed in Bouin's solution for microscopic analysis and in Gilson's solution for an analysis of fecundity. Positive allometry was recorded at the three study sites. The sex ratio for the total period was 3.29F:1M (LA), 2.43F:1M (LC) and 2.15F:1M (LV). Mean length at first sexual maturity was estimated at 10.60 cm (LA), 10.84 cm (LC) and 11.12 cm (LV). The period from March to May was defined as the breeding season for this species in the three lakes. Mean absolute fecundity was 21,634 oocytes (LA), 16,357 oocytes (LC) and 25,898 oocytes (LV). The information obtained through this study indicates that, in addition to being important spawning areas, the three lakes are interconnected in relation to the migratory dynamics of H. affinis, so it is necessary to arrive at a model that would satisfactorily cover the three lakes, considering that the dam has a negative effect on Lake Viana.
DOI: 10.6084/m9.figshare.20011306
title: Induction of bud development in apple trees with the application of vegetable and mineral oils

description: ABSTRACT The aim of this study was to determine the efficiency of vegetable oils mixed with mineral oil in the induction of budding, the activity of the enzymes catalase and guaiacol peroxidase on the buds, and productivity in the apple. The research was carried out at the State University of the Centeral-West (Unicentro), in Guarapuava, in the State of Paraná, Brazil, on both growing plants and plants at the start of production (2013/2014 and 2014/2015 respectively), using the Royal Gala II and Fuji Supreme cultivars of the apple. The treatments consisted of the application of mineral oil and mineral oil mixed with emulsifiable vegetable oil, vegetable oils from the soybean and sunflower, and hydrogenated cyanamide. Evaluation consisted of verifying budding and enzymatic activity, vegetative development, flowering phenology and productive characteristics. In the Fuji Supreme cultivar, a mixture of 2% mineral oil and 4% emulsifiable vegetable oil has the potential to induce budding, reduce plant vigour, and the concentration and anticipation of flowering, and increase both the number of fruits per plant and productivity. A mixture of mineral and vegetable oil is less efficient in the induction of budding in the Royal Gala II cultivar, when compared to mineral oil with hydrogen cyanamide. The application of mineral and vegetable oil does not alter the activity of the enzyme catalase, and none of the products tested alters the activity of the enzyme guaiacol peroxidase 24 hours after application.
DOI: 10.6084/m9.figshare.20011306.v1
title: Induction of bud development in apple trees with the application of vegetable and mineral oils

description: ABSTRACT The aim of this study was to determine the efficiency of vegetable oils mixed with mineral oil in the induction of budding, the activity of the enzymes catalase and guaiacol peroxidase on the buds, and productivity in the apple. The research was carried out at the State University of the Centeral-West (Unicentro), in Guarapuava, in the State of Paraná, Brazil, on both growing plants and plants at the start of production (2013/2014 and 2014/2015 respectively), using the Royal Gala II and Fuji Supreme cultivars of the apple. The treatments consisted of the application of mineral oil and mineral oil mixed with emulsifiable vegetable oil, vegetable oils from the soybean and sunflower, and hydrogenated cyanamide. Evaluation consisted of verifying budding and enzymatic activity, vegetative development, flowering phenology and productive characteristics. In the Fuji Supreme cultivar, a mixture of 2% mineral oil and 4% emulsifiable vegetable oil has the potential to induce budding, reduce plant vigour, and the concentration and anticipation of flowering, and increase both the number of fruits per plant and productivity. A mixture of mineral and vegetable oil is less efficient in the induction of budding in the Royal Gala II cultivar, when compared to mineral oil with hydrogen cyanamide. The application of mineral and vegetable oil does not alter the activity of the enzyme catalase, and none of the products tested alters the activity of the enzyme guaiacol peroxidase 24 hours after application.
DOI: 10.6084/m9.figshare.20011312
title: Treatments to increase, accelerate and synchronize emergence in seedlings of mucuna-preta

description: ABSTRACT Stizolobium aterrimum, known locally as mucuna-preta, is a legume used in the recovery of degraded soils. However, dormancy has a negative impact on seed germination and establishment of the seedlings. The aim was to select treatments to eliminate dormancy in seeds of mucuna-preta, thereby accelerating and synchronising seedling emergence. The experiment was carried out in a completely randomised design with 10 treatments, each with four replications of 25 seeds. The treatments were a control (intact seeds), immersion in water heated to 60 ºC, mechanical scarification with an electric emery scarifier for one second in the distal region of the seed, and scarification with sulphuric acid (H2SO4 98%) for 5, 10, 15, 20, 25, 30 and 35 minutes. The evaluations were made with tests for seedling emergence, average time of emergence, speed of emergence index and relative frequency of emergence. Seedling emergence in mucuna-preta is increased, and the average time of emergence reduced by scarification in the distal region of the seed and immersion in sulphuric acid for periods of 5 to 35 minutes. Treatment with the acid for 10 to 20 minutes increases, accelerates and synchronizes seedling emergence in black mucuna, but 10 minutes will reduce the period of contact with the H2SO4.
DOI: 10.6084/m9.figshare.20011312.v1
title: Treatments to increase, accelerate and synchronize emergence in seedlings of mucuna-preta

description: ABSTRACT Stizolobium aterrimum, known locally as mucuna-preta, is a legume used in the recovery of degraded soils. However, dormancy has a negative impact on seed germination and establishment of the seedlings. The aim was to select treatments to eliminate dormancy in seeds of mucuna-preta, thereby accelerating and synchronising seedling emergence. The experiment was carried out in a completely randomised design with 10 treatments, each with four replications of 25 seeds. The treatments were a control (intact seeds), immersion in water heated to 60 ºC, mechanical scarification with an electric emery scarifier for one second in the distal region of the seed, and scarification with sulphuric acid (H2SO4 98%) for 5, 10, 15, 20, 25, 30 and 35 minutes. The evaluations were made with tests for seedling emergence, average time of emergence, speed of emergence index and relative frequency of emergence. Seedling emergence in mucuna-preta is increased, and the average time of emergence reduced by scarification in the distal region of the seed and immersion in sulphuric acid for periods of 5 to 35 minutes. Treatment with the acid for 10 to 20 minutes increases, accelerates and synchronizes seedling emergence in black mucuna, but 10 minutes will reduce the period of contact with the H2SO4.