Search

Inadequate management of nitrogen fertilization, due to high costs, compromises the nutrition and productivity of winter forage plants, highlighting the need to adopt sustainable alternatives, such as using nitrogen-fixing bacteria. This research evaluated the growth promotion of black oat (Avena strigosa) and ryegrass (Lolium multiflorum) plants inoculated with Azospirillum brasilense rhizobacteria. The experiments were carried out over two consecutive harvests in Santa Maria, Brazil. The sowing density was 300 viable seeds per square meter for black oats and 100 viable seeds per square meter for ryegrass. A dose of 5 ml per kg of seeds from the consortium was used as an inoculant. Following sowing, the seeds were incorporated into the soil through light harrowing. At the beginning of tillering, 50 kg of N ha-1 was applied to create treatments with and without nitrogen. Plant emergence, plant height, number of leaves and tillers were evaluated. In the first year, an inoculation response was observed for the number of black oat plants emerged m-2. In the second year (corn residue), an inoculation response was observed for the number of leaves and height of black oats. Under soybean straw for oat leaf number and ryegrass tiller number. The current research highlights the effectiveness of inoculation with Azospirillum brasilense in promoting significant improvements in the morphological components of forage crops. Following corn, an increase in the number of leaves and tillers was observed, as well as in the height of black oats. Similarly, following soybeans, there was an increase in the number of black oat tillers and the number of ryegrass leaves. The results emphasize the importance of inoculation as an effective practice to enhance crop development and performance in agricultural systems, improving sustainability and productivity under soybean and corn residues. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the impact of various row spacings on the morphology, components of grain yield, and overall grain yield of soybean. The experiments were conducted over two planting seasons (2014/2015 and 2015/2016) using two planting dates (November and December) and two cultivars, FPS Urano RR and BMX Tornado RR. The row spacings tested were: 45 cm (wide row), 45 × 45 cm (cross row), 22.5 × 45 cm (twin row), and 22.5 cm (narrow row). Measurements included leaf area index and sunlight interception at R2 stage, as well as grain yield components and overall grain yield. Narrow rows, in addition to achieving canopy closure, also demonstrated enhanced sunlight interception at the R2 stage. However, the positive effect of increased sunlight interception on grain yield was only significant for the December planting date, with no notable difference observed for the November planting date. These findings imply that while narrow rows may offer advantages, particularly in later planting dates, their implementation should be carefully considered and may not consistently lead to increased grain yield, reinforcing the continued preference for conventional row spacing. [ABSTRACT FROM AUTHOR]

Integrated crop-livestock system (ICLS) can help improve the soil physical attributes, increasing the nutrients cycling and yield potential. We evaluated the effect of forage height management under ICLS on physical soil attributes and water infiltration. Field experiment was carried out for two consecutive years in a randomized complete block design, with three repetitions. Forage was managed under continuous grazing, grazing up to 30 cm (G30), 20 cm (G20) and 10 cm (G10) of height, and control without grazing. Soil bulk density (SBD), microporosity (MIP), macroporosity (MAP), and total porosity (TP) were measured before and after the grazing at 0-5; 5-10 and 10-20 cm layer depth. Water infiltration rate was evaluated using the concentric rings in eight periods (5, 10, 15, 20, 30, 60, 90 e 120 min after beginning of the process). SBD at 0-5 cm layer was not affected by the grazing management, whereas the MIP, MAP, and TP reduced after sheep grazing compared to ungrazed. Water infiltration rate was higher for the G10 management, with greater amount of accumulated infiltrated water. Path analysis showed positive effects of the soil physical attributes under ICLS to the grain yield soybean, allowing the farmers to enhance their profitability. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Growth-promoting bacteria Azospirillum brasilense, used as an inoculant in corn culture, can be severely affected by the exposure temperature, with a lethal effect above 35°C, when cultivated alone under laboratory conditions. Such effects may limit the associative interaction between plant-bacteria, with reduced inoculation efficiency, resulting in a lower growth rate of the plant and an increase in oxidative stress. Thus, the objective of the research was to evaluate the efficiency of the inoculation process with A. brasilense in seeds and in the initial growth of seedlings of two corn cultivars submitted to different temperatures. Were utilized corn hybrids seed Syn 488 and Syn 505. The experimental design was completely randomized in a 2 x 4 factorial scheme (with and without inoculation of A. brasilense x 4 sowing temperatures: 20, 25, 30, and 35°C), with four replications. The inoculation efficiency in corn seedlings submitted to different temperatures was evaluated through the following tests: germination, first count, seedling length and dry weight. In addition, responses at the biochemical level of the interaction (temperatures x inoculation) for the content of photosynthetic pigments and hydrogen peroxide (H2O2), antioxidant enzymes and lipid peroxidation were evaluated. The inoculation with A. brasilense changed the morphological and biochemical responses of corn seedlings, and the inoculation process was efficient for all temperatures tested. The best results were under temperatures 25, 30, and 35°C. Plant and bacteria when exposed to temperature conditions (30°C inoculated) showed a significant increase in plant biomass and activity of antioxidant enzymes. [ABSTRACT FROM AUTHOR]

Nitrogen is available in insufficient quantities in Brazilian soils, and is the nutrient that raises the most cost of production of maize. Nowadays there is a more interest in the use of alternative nitrogen sources, such as biological nitrogen fixation, to supply plant demand. Among the most used bacteria in association with grasses is Azospirillum brasilense. In this way this study aimed to establish a relationship between the genetic bases of corn and the forms of A. brasilense application and the effects on the plant morphological components, grain yield, and relative nitrogen contribution. Experiments were conducted during the 2013/14 and 2014/15 crop seasons. The experiments included two single hybrids, two double hybrids, and two triple hybrids inoculated with A. brasilense via seed treatment; foliar application during phenological stages V2, V2 + V4, and V4; and a control treatment without bacteria. The response varied with the hybrid and the year. In the 2013/14 crop, a significant difference was observed in the grain yield for the single hybrid AG9045 inoculated with A. brasilense via seed and foliar application in V2. In the 2014/15 crop, inoculation with A. brasilense via seed application resulted in significant increases in the grain yield for the triple hybrid BG7051. Foliar application of A. brasilense is an efficient alternative for the improvement of plant morphological traits, and inoculation via seed and with foliar application in V2 increases the relative contribution of N. [ABSTRACT FROM AUTHOR]

Desiccation practiced during the preharvest period contributes to mechanized seed harvesting. This work aimed to verify whether wheat preharvest desiccation influences the morphological and physiological characteristics of the seedlings produced from the seeds of desiccated plants. The preharvest treatments included a combination of herbicides (glufosinate-ammonium, glyphosate, and paraquat) and phenological application stages (Zadoks: 83, 85, 87, and 92), as well as a control treatment (without application). Two wheat cultivars were used (BRS Parrudo and TBIO Sinuelo). Herbicide applications were observed to decrease the length and projected area of the shoots by 52 and 46%, respectively, as well as reduce the length, surface area and root volume when compared to the control treatment without application. The hydrogen peroxide concentration, as well as the enzymatic activity of guaiacol peroxidase, was observed to rise only in the treatments where the herbicides were applied. Physiologically, an increased hydrogen peroxide output was revealed, while the guaiacol peroxidase enzymatic activity increased in both cultivars, but with no effect noted in the superoxide dismutase enzymatic activity. The shoot and root morphology were negatively influenced, showing a rise in the enzymatic activity and hydrogen peroxide concentration in the seedlings from the desiccated plants. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare two methods of estimating leaf area (leaf area meter LI-COR 3100 and ImageJ software) in oats. Renascem black oats and UTF Iguaçu white oats cultivars were evaluated. All the leaves of one plant per plot, with six repetitions, were evaluated every seven days to obtain five assessments for each cultivar. The leaves were identified and fixed on a white A4 sheet of paper with an indication of a known area (45 cm²), photographed and evaluated using a leaf area meter (LI-3100 - LI-COR). Leaf area was then estimated using ImageJ software. Estimates were obtained for standard deviation and coefficient of variation, and a simple linear regression equation was estimated based on the two estimation methods. Mean variances were tested using the 'F'-test and the means compared by the 't'-test. There was no difference between the leaf areas found by both methods. In addition, they were highly correlated, and variances were homogeneous. We concluded that ImageJ software can be used instead of the leaf area meter on the two oat cultivars evaluated. [ABSTRACT FROM AUTHOR]

Copyright of Scientia Agraria Paranaensis is the property of Revista Scientia Agraria Paranaensis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ceres is the property of Revista Ceres and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum: Agronomy is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There are several factors that may compromise the initial establishment of wheat crops, reduce the plant populations, and consequently affect yield components and grain yield. The objective of this study was to produce reseeding recommendations for wheat crops affected by reduced plant stands based on an economic analysis of the yield cost and the expectation of financial return. Experiments were conducted during two agricultural years (2011 and 2012) in the Experimental da Coxilha area, which belongs to the Department of Plant Science of Universidade Federal de Santa Maria, in the state of Rio Grande do Sul (Brazil). Random removals of wheat plants were undertaken, corresponding to 0, 20, 40, and 60% of the initial population of plants for the following cultivars: Fundacep Horizonte, Marfim, Fundacep Campo Real, Mirante and Quartzo. The characteristics that were evaluated included the number of plants and ears, as well as the grain yield. The Fundacep Horizonte, Marfim and Fundacep Campo Real cultivars were stable and able to compensate for losses caused by reductions in the plant stands. The yield production of Mirante and Quartz cultivars was dependent on the number of established plants and therefore relied on good establishment of the initial crop and no subsequent losses. Thus, the findings of this study indicate that the Mirante and Quartz cultivars do not compensate for reductions in plant populations and need to be reseeded if the number of plants is not appropriate. In such cases, the economic viability of reseeding can be quantified. In contrast, the Fundacep Horizonte, Marfim, and Fundacep Campo Real cultivars are more stable, and reseeding is not economically justified at these locations. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite the great importance of soybeans in Brazil, there have been few applications of soybean crop modeling on Brazilian conditions. Thus, the objective of this study was to use modified crop models to estimate the depleted and potential soybean crop yield in Brazil. The climatic variable data used in the modified simulation of the soybean crop models were temperature, insolation and rainfall. The data set was taken from 33 counties (28 Sao Paulo state counties, and 5 counties from other states that neighbor São Paulo). Among the models, modifications in the estimation of the leaf area of the soybean crop, which includes corrections for the temperature, shading, senescence, CO2, and biomass partition were proposed; also, the methods of input for the model's simulation of the climatic variables were reconsidered. The depleted yields were estimated through a water balance, from which the depletion coefficient was estimated. It can be concluded that the adaptation soybean growth crop model might be used to predict the results of the depleted and potential yield of soybeans, and it can also be used to indicate better locations and periods of tillage. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Forage production evaluation according to forage species and period within growing season is important to adjust forage budget. The aim of this trail was to evaluate forage accumulation rate of cool-season annual grasses on four sowing dates. This study was carried out from March 2009 to November 2009 to evaluate forage accumulation rate on cool-season forage grasses (Black oat, rye, ryegrass, wheat, and triticale) on four sowing dates: March llth, April 8th, May 6th, and June 3rd. Forage production was converted into daily accumulation rate. Significant forage species vs sowing date interaction was verified for all variables analyzed, indicating several possible combinations between forage species and sowing date. Highest production were observed for white oats 'UTF Iguaçu' and 'IPR 126', black oat 'IAPAR 61', annual ryegrass cultivars and rye, which presented average of 51.4kg DM/ha after first cut, showing a great performance in terms of forage production and maintenance of their forage production, especially when sowed before early May. [ABSTRACT FROM AUTHOR]