Janaina RC Rouws

• Brazilian Agricultural Research Corporation (EMBRAPA)

Parapiptadenia rigida é uma leguminosa arbórea fixadora de N, nativa da Mata Atlântica do Sul do Brasil, comumente usada na arborização urbana, restauração de matas ciliares e SAFs. Com objetivo de avaliar o crescimento de mudas de Parapiptadenia rigida inoculadas com rizóbios e fungos micorrízicos arbusculares (FMAs) em condições de viveiro e no c...

Neotropical Beta-rhizobia have a particular affinity to the large legume (Fabaceae) genus Mimosa and some of its relatives in the tribe Mimosae of the Caesalpinioideae subfamily. However, little is still known about the ecology of this interaction, especially the relationship between the rhizobia of "widespread" pan-tropical Mimosa species like M....

Neotropical Beta-rhizobia have a particular affinity to the large legume (Fabaceae) genus Mimosa and some of its relatives in the tribe Mimosae of the Caesalpinioideae subfamily. However, little is still known about the ecology of this interaction, especially the relationship between the rhizobia of Widespread pan-tropical Mimosa species like M. pu...

The objective was to evaluate the sensitivity of Piptadenia gonoacantha seeds to desiccation and storage conditions. The seeds were subjected to artificial drying in a forced air convection oven (39.7 °C ± 0.78 and 28.1% ± 1.90 RH) for different periods. After each drying period, evaluation methods were performed to determine the seeds water conten...

Background and Aims Nitrospirillum amazonense strain CBAmC is a nitrogen-fixing bacterium that has been used for sugarcane inoculation. Despite its beneficial effects, however, little is known about the establishment and colonization of this microorganism in its inoculated host plant. Furthermore, alternative inoculation methods need to be tested i...

O uso de plantas de cobertura de solo nas rotações de cultivo de hortaliças nos ambientes de montanha de Nova Friburgo - RJ tem sido adaptado empiricamente às condições locais pelos agricultores. Nesse sentido, objetivou-se estabelecer conhecimentos acerca da relação de diferentes épocas de plantio e de corte das plantas, com o aporte de fitomassa...

Elephant grass (Pennisetum purpureum) is a perennial C4-plant with outstanding sustainable potential for bioenergy, grazing and silage, It is able to fix nitrogen in association with diazotrophic bacteria and is a high biomass producer, even in low fertility soils. This study aimed to investigate the response of two elephant grass genotypes (PCEA a...

The objective of this work was to evaluate the sensitivity of Melanoxylon brauna Schott. tree legume seeds to desiccation and storage. In the drying experiment, the Melanoxylon brauna seeds were submitted to two drying conditions: a forced air circulation chamber (40.18 °C ± 0.13 and 28.48% ± 3.95 RH) and a silica gel desiccator (27.19 °C ± 1.28 an...

Aims Rhizobia are common members of plant microbiomes. This study aimed to evaluate if rhizobia can colonize sugarcane mini-setts and if and how they affect sprouting and morphological traits of plant development. Methods Bradyrhizobium sacchari strain BR 10280T and Rhizobium sp. strain BR 10268 were inoculated on sugarcane mini-setts and sproutin...

The objective of this work was to evaluate the vegetative propagation of Hymenaea courbaril (jatobá) and Apuleia leiocarpa (garapa) using the mini-cutting technique with the use of indolebutyric acid (IBA) growth regulator in different types of mini-cuttings. Two experiments were set up: the first involving the two species and three mini-cutting te...

The existence of large population of ineffective native rhizobia and inconsistent performance of exotic strains in Ghanaian soils necessitate the need to identify effective and locally adapted elite strains for enhanced legume-rhizobium symbiosis. This study was designed to test the suitability of two previously selected potential elite Bradyrhizob...

The present study aimed to evaluate the effect of inoculation with nitrogen-fixing bacteria (NFB) and arbuscular mycorrhizal fungi (AMF) on the development of Tachigali vulgaris seedlings under nursery conditions. The seedlings were produced in 1 kg bags on a substrate of sand and vermiculite (1:1), following a completely randomized experimental de...

The study was carried out to evaluate sediment production, water infiltration and surface runoff in an Ultisol under simulated rainfalls with similar erosivity, but different combinations of intensity (Int) and duration (Dur). The rainfalls were applied after soil tillage in the period from August to September 2017, in Seropédica, RJ State, Brazil....

A reliable quantification of nitrogen (N) losses by ammonia (NH3) volatilization can contribute to identifying optimized strategies of fertilizer management. The objective of this study was to quantify ammonia volatilization from several organic N sources incorporated into or applied onto the soil surface. Two cultivation areas, under snap bean and...

Factitious prey are preferentially used to rear lady beetles in the laboratory in lieu of natural prey with an aim towards facilitating and lowering the cost of producing these predators. We tested the hypothesis that live dipteran larvae of Drosophila melanogaster Meigen (factitious prey) meet the nutritional requirements of the coleopteran Coleom...

The fast-growing C4 grass Pennisetum purpureum, commonly known as elephant grass, produces large amounts of biomass and usually does not demand large quantities of N-fertilizer. Furthermore, the biological Nitrogen fixation (BNF) quantification of several Pennisetum varieties showed that N derived from the biological process varied from 14 to 40%....

This study was carried out to evaluate the contributions to the optimization of water use in a carrot crop under different forms of mulch using Gliricidia sepium, fertilization with castor bean cakes and irrigation water depths. The experiment was conducted in Seropédica, RJ, Brazil (22º 46’ S and 43º 41’ W), from June to September 2010. The experi...

Aims The evaluation of ¹⁵N abundance of N derived from biological N2 fixation (BNF) in legume shoots (‘BS’ value) is essential for quantifying BNF inputs to field-grown legumes. The aim of this study was to investigate the impact of shading, development stage of soybean (Glycine max) and rhizobium strain on the ‘BS’ value. Methods Soybean plants w...

Grasshoppers of the families Acrididae and Romaleidae (Orthoptera) are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antônio de Pádua, RJ (Brazil)...

O trabalho teve como objetivo avaliar a eficiência de métodos de quebra de dormência em sementes de Albizia pedicellaris em laboratório. Foram aplicados 10 tratamentos pré-germinativos: escarificação química com imersão em ácido sulfúrico por 5, 10, 15 e 30 minutos, escarificação física, seguida ou não de embebição em água por 6, 12 e 24 horas, cho...

Coffee roasting needs precise control and innovative techniques that are economically viable to motor and improve its consistency. In this study, mass spectrometry was used as a tool to screen chemical markers that appear on the surface of coffee beans (whole bean) along the roasting process. A non-target and non-volatile approach was used with an...

Aims The primary aim of this review is to determine if methods based on ¹⁵N enrichment (E) and ¹⁵N natural abundance (NA) give consistent estimates of the proportional dependence of N2-fixing species on biological N2 fixation (Patm), and secondly to attempt to explain any inconsistencies that may be found. Methods Published estimates of the symbio...

Knowledge of the composition and distribution of native entomopathogenic fungal species are essential to evaluate the potential of biological control in a given ecosystem. In this study, 10 soil samples were collected in two seasons (dry and rainy) in the Curió Municipal Natural Park in Paracambi and the presence of entomopathogenic fungi species w...

The piçarra (subsoil material mainly formed by silt, sand and gravel) is commonly used in the civil construction and activities related to the onshore oil production in the Caatinga biome. The revegetation of the piçarra mines at the end of exploration cycle is mandatory and generally demands the planting of native tree species. However, there is s...

The increasing level of land degradation has led to the adoption of agricultural management practices that seek to combine agricultural production and soil conservation. Among these, the practice of Crop-Livestock Integration (CLI) has intensified in West-Central Brazil. In order to assess the long-term effect of the CLI system and seasonality on t...

The increasing level of land degradation has led to the adoption of agricultural management practices that seek to combine agricultural production and soil conservation. Among these, the practice of Crop-Livestock Integration (CLI) has intensified in West-Central Brazil. In order to assess the long-term effect of the CLI system and seasonality on t...

The study of organic matter and its compartments and their relationship with management, aims to develop strategies for increasing their levels in soils and better understanding of its dynamics. This work aimed to evaluate the fractions of soil organic matter and their carbon stocks in different soil cover system in crop-livestock integration and n...

The study of organic matter and its compartments and their relationship with management, aims to develop strategies for increasing their levels in soils and better understanding of its dynamics. This work aimed to evaluate the fractions of soil organic matter and their carbon stocks in different soil cover system in crop-livestock integration and n...

The study of organic matter and its compartments and their relationship with management, aims to develop strategies for increasing their levels in soils and better understanding of its dynamics. This work aimed to evaluate the fractions of soil organic matter and their carbon stocks in different soil cover system in crop-livestock integration and n...

The purpose of this study was to investigate the influence of potassium and nitrogen on the severity of black rot and yield of head. The experiment was carried out in split plots with factorial subplots, in randomized blocks with four replications. In the plots we assessed the influence of inoculation (injured plants with distilled water and inocul...

The effects of organic fertilization combining cattle manure and pigeon pea shoots on the culture of rocket, planted with one or two plants per hole, including soil microbial biomass carbon, soil respiration, the metabolic quotient, soil fumigation labile carbon, and the dry matter content and total N, K, P, Ca and Mg contents in the leaves and roo...

Although Coffea arabica species has its origin in the African understories, there is great resistance on the part of the Brazilian producers for growing this species under agroforestry systems as they fear that shading reduces production. This study aimed at evaluating some vegetative traits and the productivity of organically grown coffee (Coffea...

Resumo – O objetivo deste trabalho foi avaliar o efeito de diferentes arranjos espaciais no desempenho agronômico de mucuna-verde (Mucuna pruriens var. utilis). O experimento consistiu de oito tratamentos, dispostos em delineamento de blocos ao acaso em arranjo fatorial 2x4, com quatro repetições. Os tratamentos foram semeadura da mucuna-verde, em...

The objective of this work was to assess the effect of different coffee organic cultivation systems on chemical and biological soil characteristics, in different seasons of the year. The following systems were evaluated: coffee intercropped with one (CJ1), two (CJ2) or three (CJ3) pigeon pea (Cajanus cajan) alleys; coffee planted under full sun (CS...

A key contribution to study the cycling of nutrients in soil/plant/animal systems is the evaluation of the consumption of forage and their nutrients by cattle. The objective of this study was to test techniques to evaluate faecal production, in vitro digestibility, forage consumption and the proportion of legume in the acquired diet. Five Zebu stee...

As características físicas das chuvas determinam sua erosividade, que constitui importante fator nas relações de causa e efeito do processo erosivo dos solos, sendo sua caracterização fundamental para o planejamento conservacionista. Este trabalho foi realizado com o objetivo de avaliar a distribuição dos atributos das chuvas (altura precipitada, d...

The infestation indices by fruit flies were determined for six cultivars of Coffea arabica L. in shaded and unshaded systems under organic management. The experiment was set in a completely randomized design with a split-split-plot arrangement and four replicates. A 250g-sample of maturing fruits per plot was harvested in May 2005. The cultivars Ic...

Frugivorous flies have been acquiring great economic importance in coffee crop because they cause premature dropping of coffee beans and significantly decrease the quality of the beverage. The coffee plant is also a natural reservoir of Tephritidae species that infest fruits of economic importance. This study evaluated the influence of the shaded a...