cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7215722.v1
title: Sorption and Desorption of Diuron, Hexazinone and Mix (Diuron + Hexazinone) in Soils With Different Attributes

description: ABSTRACT: In Brazil, sugarcane is grown in large areas. Weed control in sugarcane fields is done by chemical method, since it is more efficient and less expensive. In this method, herbicides that persist in the environment for long periods are used, among which there are hexazinone and diuron, which are applied in mixtures marketed by the industry. This research evaluated the sorption and desorption of hexazinone and diuron applied alone and in mixture, in two samples of Red-Yellow Latosols (LVAG and LVAV) and a Organosol (OR), with and without manure. Sorption isotherms were built using the batch equilibrium method and the identification and quantification of herbicides was obtained through a high-performance liquid chromatography (HPLC) with UV-Vis detector. There were high diuron sorption coefficients (Kf) in the soils. The hexazinone Kf values found were low in LVAG and LVAV soils, and they were high ground only in OR. In all soils, diuron and hexazinone showed higher Kf values when mixed. There was a direct relation between the addition of manure to the substrate and the Kf values . Higher desorption values (Kfd) in relation to those of sorption in LVAG and LVAV soils indicate gradual release of these herbicides in the soil solution when using organic fertilizer, showing increased sorption and desorption of these molecules; this is accentuated when they are mixed. In the Organosol, desorption was very low, and cannot be quantitated by the used method. It is possible to conclude that the incubation of LVAG and LVAV soil with manure helps both the process of sorption and desorption of herbicides. However, sorption and desorption in the Organosol is high indicating very low agrochemicals such strong bonds with soil colloids.
DOI: 10.6084/m9.figshare.7215716
title: Photosynthetic Potential and Productivity of Common Beans under Herbicide Effect

description: ABSTRACT: The objective of this study was to evaluate the effects of the application of contact herbicides recommended for common bean crops, as for chlorophyll a fluorescence parameters, leaf soluble proteins content (LSPC) and productivity. The experiment was conducted on the field with five treatments, which were the application of the following herbicides: bentazon (720 g ha-1), fluazifop-p-butil (187.5 g ha-1), fomesafen (250 g ha-1) fluazifop-p-butil + fomesafen (187.5 + 250 g ha-1), and a manually weeded control treatment without herbicide application, in a randomized block design with four replications. Bentazon was the only herbicide causing significant reductions, but only until the first day after herbicide application (DAA), on the following chlorophyll a fluorescence parameters: maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield of photosystem II (ϕPSII), photochemical quenching (qP); it also induced an increase in non-photochemical quenching (NPQ). Fv/Fm was the best parameter to indicate herbicide effect on the photosynthetic apparatus of plants in the field. Chlorophyll a fluorescence parameters obtained in light-adapted leaves underwent a high environmental influence, especially deriving from the variation in the photosynthetic photon flow density (PPFD) during measurements; they are not recommended to evaluate the effects of herbicides on the field. None of the applied herbicides evaluated caused reductions in grain yield; therefore, they are recommended for common bean crops.
DOI: 10.7284/130987
title: CTD (Conductivity, Temperature, Depth) data collected during research cruise SP1833 using a Sea-Bird SBE-911+ instrument system onboard the platform RV Robert Gordon Sproul

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7215713
title: Growth and Accumulation of Nutrients by Weeds, in Maize and Legumes Intercrops

description: ABSTRACT: The presence of weeds on fields is a concern for farmers, due to competition with the commercial crops, reducing yields. The intercropping of maize with legumes provides weed control; after senescence, the nutrients accumulated by plants are released, recycling nutrients. The study of plant species and their diversity is called phytosociology. This study aimed at evaluating the accumulation of dry phytomass by maize intercropped with legumes and weeds species, and at evaluating nutrient cycling and the phytosociology of weeds. The experiment consisted of maize intercropped with legumes cover crops: jack-beans, Brazilian jack-beans, velvet bean, lablab-beans, and pigeon pea, and the control treatment (maize without intercrop), all without chemical or mechanical weed control. Maize was sown in the plots, and legumes were sown 64 days after maize. Maize was harvested 120 days after sowing (DAS), and legumes at 144 DAS. Weeds were sampled at 84 and 144 DAS. It was possible to evaluate the accumulation of dry phytomass, the nutrient content of the intercrop components, and the phytosociology of weeds. The phytomass accumulation by maize was not affected by the intercrop with legumes. The intercrop with velvet bean accumulated higher dry phytomass and suppressed weeds. Jack beans accumulated dry mass, but did not suppress weeds. The intercropping system changed the diversity of weeds. Panicum maximum, Commelina nudiflora, Commelina benghalensis, Leonotis nepetaefolia and Melampodium divaricatum stood out by presenting higher values of phytosociological index and nutrient recycling.
DOI: 10.6084/m9.figshare.7215710
title: Subfossil and periphytic diatoms from the upper Paraná river, Brazil: last ~1000 years of a transition period

description: ABSTRACT Considering the lack of knowledge regarding the paleolimnology and the diatom flora from the sediment in Brazilian aquatic environments, this study aimed to provide information about diatom biodiversity and autoecology in an environment located in the upper Paraná river floodplain. Sediment and periphytic samples were collected from a swamp located in an island of the upper Paraná river floodplain. Sediment samples were obtained by collecting a core of ~2 m with a calibrated date of 726 to 903 cal yr BP near the base. The core was sliced into layers of 2.5 cm, totaling 41 samples. Periphytic diatom samples were obtained by scraping macrophytes' petioles, totaling two samples. The community was represented by 31 species belonging to 15 genera. All of the taxa were found in the sediment record, and 15 were present in the periphyton. The three new records (Eunotia longicamelus, Planothidium bagualensis and Luticola hustedtii) reinforce the importance of paleolimnological and periphytic studies to increase information about the aquatic biodiversity.
DOI: 10.6084/m9.figshare.7215716.v1
title: Photosynthetic Potential and Productivity of Common Beans under Herbicide Effect

description: ABSTRACT: The objective of this study was to evaluate the effects of the application of contact herbicides recommended for common bean crops, as for chlorophyll a fluorescence parameters, leaf soluble proteins content (LSPC) and productivity. The experiment was conducted on the field with five treatments, which were the application of the following herbicides: bentazon (720 g ha-1), fluazifop-p-butil (187.5 g ha-1), fomesafen (250 g ha-1) fluazifop-p-butil + fomesafen (187.5 + 250 g ha-1), and a manually weeded control treatment without herbicide application, in a randomized block design with four replications. Bentazon was the only herbicide causing significant reductions, but only until the first day after herbicide application (DAA), on the following chlorophyll a fluorescence parameters: maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield of photosystem II (ϕPSII), photochemical quenching (qP); it also induced an increase in non-photochemical quenching (NPQ). Fv/Fm was the best parameter to indicate herbicide effect on the photosynthetic apparatus of plants in the field. Chlorophyll a fluorescence parameters obtained in light-adapted leaves underwent a high environmental influence, especially deriving from the variation in the photosynthetic photon flow density (PPFD) during measurements; they are not recommended to evaluate the effects of herbicides on the field. None of the applied herbicides evaluated caused reductions in grain yield; therefore, they are recommended for common bean crops.
DOI: 10.7284/130985
title: GNSS (Global Navigation Satellite System) data collected during research cruise SP1833 using a Garmin GPS-17HVS instrument system onboard the platform RV Robert Gordon Sproul

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7215710.v1
title: Subfossil and periphytic diatoms from the upper Paraná river, Brazil: last ~1000 years of a transition period

description: ABSTRACT Considering the lack of knowledge regarding the paleolimnology and the diatom flora from the sediment in Brazilian aquatic environments, this study aimed to provide information about diatom biodiversity and autoecology in an environment located in the upper Paraná river floodplain. Sediment and periphytic samples were collected from a swamp located in an island of the upper Paraná river floodplain. Sediment samples were obtained by collecting a core of ~2 m with a calibrated date of 726 to 903 cal yr BP near the base. The core was sliced into layers of 2.5 cm, totaling 41 samples. Periphytic diatom samples were obtained by scraping macrophytes' petioles, totaling two samples. The community was represented by 31 species belonging to 15 genera. All of the taxa were found in the sediment record, and 15 were present in the periphyton. The three new records (Eunotia longicamelus, Planothidium bagualensis and Luticola hustedtii) reinforce the importance of paleolimnological and periphytic studies to increase information about the aquatic biodiversity.
DOI: 10.6084/m9.figshare.7215704
title: Potential and Persistence of the Inhibitory Effect of Sorghum on Weeds

description: ABSTRACT: The inhibitory interaction between plants may be an important strategy of integrated weed management (IWM). This study aimed to investigate the inhibitory effects of sorghum on phytosociology and infestation of weeds during cultivation and after harvest. An experiment was carried out in the field in a randomized block design in a split-plot arrangement. Plots consisted of sorghum and corn (control) and subplots were composed of different periods of weed community assessment after crop harvest (DAH) (0, 20, 40, 60, and 80 days). An increased number of species and botanical families was observed after harvest. Degradation of sorghum and corn straw reached the stabilization at 60 DAH. Although sorghum has presented a lower amount of straw and soil cover, weed infestation was, on average, 30% lower in relation to areas cultivated with corn. Sorghum showed an inhibitory effect on some weed species, influencing phytosociology, especially during the first 40 DAH, and can be used as part of IWM strategy.
DOI: 10.7284/130986
title: GNSS (Global Navigation Satellite System) data collected during research cruise SP1833 using a Ashtech ADU2 instrument system onboard the platform RV Robert Gordon Sproul

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7215698
title: Cultivation Systems, Vegetable Soil Covers and their Influence on the Phytosocyology of Weeds

description: ABSTRACT: Phytosociological studies are groups of methods that aim at the identification, composition and distribution of plant species in a community. The objective of this study was to identify and quantify the main weeds found in beans, maize and soybean cultivated in no-tillage and conventional systems. The experimental design was a randomized block one, with four replications. Experiments were conducted during three consecutive years, with summer crop (bean, maize and soybean) treatments, no-tillage system (NTS) composed by the covers, black oat, vetch and forage radish, in addition to their intercrop. In the conventional planting system (CTS), the area was left fallow in the off-season. The shoot dry matter of the covers was evaluated in each crop. The evaluated variables were: frequency, density, abundance, dry matter and the importance value index of the species in the area. Eighteen species of weeds and 12 families were identified, with Asteraceae and Poaceae families showing the highest number of individuals. The shoot dry matter production presented a difference among the covers; the cover black oat alone and intercrop with radish and vetch stood out, with the highest averages in the 3 years of the experiments. Cropping systems and different cover crops within the no-tillage system interfered in the number of encontered species. The emergence of Euphorbia heterophylla was favored, while the emergence of Lolium multiflorum was inhibited. E. heterophylla was the most encountered in the NTS areas, and its germination was negatively influenced by soil mobilization. The intercrop of black oat and vetch provided maximum weed control in soybean.
DOI: 10.6084/m9.figshare.7215701
title: News Techniques for the Application of Herbicides on Soybean Crops

description: ABSTRACT: There is a need for an increase nin efficiency and a reduction in the risk of environmental contamination in controlling weeds; this can be obtained with the development of the new techniques for the application of herbicides. The objective was to verify the efficiency of different herbicide application techniques on soybean crops (Glycine max (L.) Merrill). The experiment was conducted in a commercial area in the municipality of Sinop, Mato Grosso state. The design was a randomized block, with four replications and six treatments, namely: herbicide application with a manual backpack sprayer; application with an acrylic wool roll with 9 mm long hairs; sheep’s wool roller with 9 mm long hairs; high density polyester foam roller; weeding with a hoe and free growth (no control). The used cultivar was TMG 132. The herbicide spray used in the treatments was: glyphosate 960 g ha-1, 80 g ha-1 haloxyfop-p-methyl 600 mL ha-1 and oil, diluted in water and applied 14 and 27 days after emergence (DAE). The weed population, vegetative growth, chlorophyll content and soybean yield were evaluated. The use of the sprayer and the application with the sheep’s wool roller showed greater efficiency in weed control, but the mixture of herbicides resulted in culture phytotoxicity when applied via foliar spraying.
DOI: 10.6084/m9.figshare.7215704.v1
title: Potential and Persistence of the Inhibitory Effect of Sorghum on Weeds

description: ABSTRACT: The inhibitory interaction between plants may be an important strategy of integrated weed management (IWM). This study aimed to investigate the inhibitory effects of sorghum on phytosociology and infestation of weeds during cultivation and after harvest. An experiment was carried out in the field in a randomized block design in a split-plot arrangement. Plots consisted of sorghum and corn (control) and subplots were composed of different periods of weed community assessment after crop harvest (DAH) (0, 20, 40, 60, and 80 days). An increased number of species and botanical families was observed after harvest. Degradation of sorghum and corn straw reached the stabilization at 60 DAH. Although sorghum has presented a lower amount of straw and soil cover, weed infestation was, on average, 30% lower in relation to areas cultivated with corn. Sorghum showed an inhibitory effect on some weed species, influencing phytosociology, especially during the first 40 DAH, and can be used as part of IWM strategy.
DOI: 10.7284/130988
title: GNSS (Global Navigation Satellite System) data collected during research cruise SP1833 using a Furuno GP-150 instrument system onboard the platform RV Robert Gordon Sproul

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7215698.v1
title: Cultivation Systems, Vegetable Soil Covers and their Influence on the Phytosocyology of Weeds

description: ABSTRACT: Phytosociological studies are groups of methods that aim at the identification, composition and distribution of plant species in a community. The objective of this study was to identify and quantify the main weeds found in beans, maize and soybean cultivated in no-tillage and conventional systems. The experimental design was a randomized block one, with four replications. Experiments were conducted during three consecutive years, with summer crop (bean, maize and soybean) treatments, no-tillage system (NTS) composed by the covers, black oat, vetch and forage radish, in addition to their intercrop. In the conventional planting system (CTS), the area was left fallow in the off-season. The shoot dry matter of the covers was evaluated in each crop. The evaluated variables were: frequency, density, abundance, dry matter and the importance value index of the species in the area. Eighteen species of weeds and 12 families were identified, with Asteraceae and Poaceae families showing the highest number of individuals. The shoot dry matter production presented a difference among the covers; the cover black oat alone and intercrop with radish and vetch stood out, with the highest averages in the 3 years of the experiments. Cropping systems and different cover crops within the no-tillage system interfered in the number of encontered species. The emergence of Euphorbia heterophylla was favored, while the emergence of Lolium multiflorum was inhibited. E. heterophylla was the most encountered in the NTS areas, and its germination was negatively influenced by soil mobilization. The intercrop of black oat and vetch provided maximum weed control in soybean.
DOI: 10.6084/m9.figshare.7215701.v1
title: News Techniques for the Application of Herbicides on Soybean Crops

description: ABSTRACT: There is a need for an increase nin efficiency and a reduction in the risk of environmental contamination in controlling weeds; this can be obtained with the development of the new techniques for the application of herbicides. The objective was to verify the efficiency of different herbicide application techniques on soybean crops (Glycine max (L.) Merrill). The experiment was conducted in a commercial area in the municipality of Sinop, Mato Grosso state. The design was a randomized block, with four replications and six treatments, namely: herbicide application with a manual backpack sprayer; application with an acrylic wool roll with 9 mm long hairs; sheep’s wool roller with 9 mm long hairs; high density polyester foam roller; weeding with a hoe and free growth (no control). The used cultivar was TMG 132. The herbicide spray used in the treatments was: glyphosate 960 g ha-1, 80 g ha-1 haloxyfop-p-methyl 600 mL ha-1 and oil, diluted in water and applied 14 and 27 days after emergence (DAE). The weed population, vegetative growth, chlorophyll content and soybean yield were evaluated. The use of the sprayer and the application with the sheep’s wool roller showed greater efficiency in weed control, but the mixture of herbicides resulted in culture phytotoxicity when applied via foliar spraying.
DOI: 10.6084/m9.figshare.7215695
title: Volume of cells on trays influences hydroponic lettuce production

description: ABSTRACT Lettuce seedlings used on hydroponic cultivation (NFT) are usually produced in trays with small volume, requiring two transplants: from tray to nursery and then to the definitive place. The aim of this study was to verify lettuce performance under NFT system, using seedlings produced in trays with several cell volumes (50, 40, 35, 31, 30, 29, 27, 20 and 10 cm³ cell-1). The tray volumes are considered treatments. The experimental design was completely randomized blocks, with four replicates. Seedlings were transplanted directly to the definitive profile, except those ones produced in 10 cm³ cell-1. Two harvests were performed, at 22 and 29 days after transplant (DAT). We evaluated number of senescent leaves, total number of leaves, shoot fresh mass, root fresh mass, shoot dry mass, stem length and productivity. The best performance was obtained using seedlings produced in trays with higher volume per cell. The nursery phase was not necessary and it was possible to obtain reduction from two to one transplant, corresponding to trays of 20 to 50 cm³ cell-1. Seedlings produced in trays with 40 and 50 cm³ cell-1 made the early harvest possible, at 22 DAT of cultivation under hydroponic NFT system.
DOI: 10.7284/130989
title: GNSS (Global Navigation Satellite System) data collected during research cruise SP1833 using a Furuno GP-170 instrument system onboard the platform RV Robert Gordon Sproul

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7215692
title: Yield Losses and Economic Threshold of GR® F2 Volunteer Corn in Bean

description: ABSTRACT: Volunteer corn has high competitive capacity with bean, and the degree of interference varies as a function of corn density and origin (individual plant or clump). This study aimed to quantify bean yield losses under interference with densities of individual plants and clumps (seven plants at the same point) of GR® F2 volunteer corn and calculate the economic threshold (ET). Two experiments were carried out in a randomized blocks design with three replicates in Passo Fundo, RS, Brazil. The studied volunteer corn densities were 0, 0.5, 1, 2, 4, 8, and 12 individual plants and clumps m-2. The bean yield was assessed and calculated the yield losses (%) in response to volunteer corn interference. The yield loss data were fitted to the rectangular hyperbola model to generate the parameters for ET determining. ET was calculated as a function of cost (US$ ha-1) and control efficiency (%) of volunteer corn, the price paid for bean (US$ kg-1), and bean yield (kg ha-1). Interferences caused by densities of volunteer corn of 0.5, 1, and 2 individual plants and clumps m-2 in bean resulted in yield losses of 9%, 17%, and 30%, and 33%, 51%, and 70%, respectively. The ET of volunteer corn on bean was, on average, 0.21 individual plants m-2 and 0.04 clumps m-2. Increases in yield and price paid for beans, higher efficiency of volunteer corn control, and a decrease in costs of control promote a reduction in ET. Interferences caused by clumps resulted in higher bean yield losses than individual plants.
DOI: 10.6084/m9.figshare.7215695.v1
title: Volume of cells on trays influences hydroponic lettuce production

description: ABSTRACT Lettuce seedlings used on hydroponic cultivation (NFT) are usually produced in trays with small volume, requiring two transplants: from tray to nursery and then to the definitive place. The aim of this study was to verify lettuce performance under NFT system, using seedlings produced in trays with several cell volumes (50, 40, 35, 31, 30, 29, 27, 20 and 10 cm³ cell-1). The tray volumes are considered treatments. The experimental design was completely randomized blocks, with four replicates. Seedlings were transplanted directly to the definitive profile, except those ones produced in 10 cm³ cell-1. Two harvests were performed, at 22 and 29 days after transplant (DAT). We evaluated number of senescent leaves, total number of leaves, shoot fresh mass, root fresh mass, shoot dry mass, stem length and productivity. The best performance was obtained using seedlings produced in trays with higher volume per cell. The nursery phase was not necessary and it was possible to obtain reduction from two to one transplant, corresponding to trays of 20 to 50 cm³ cell-1. Seedlings produced in trays with 40 and 50 cm³ cell-1 made the early harvest possible, at 22 DAT of cultivation under hydroponic NFT system.