Improving the Comprehension of Pathogenicity and Phylogeny in 'Candidatus Phytoplasma meliae' through Genome Characterization.

'Candidatus Phytoplasma meliae' is a pathogen associated with chinaberry yellowing disease, which has become a major phytosanitary problem for chinaberry forestry production in Argentina. Despite its economic impact, no genome information of this phytoplasma has been published, which has hindered its characterization at the genomic level. In this study, we used a metagenomics approach to analyze the draft genome of the 'Ca. P. meliae' strain ChTYXIII. The draft assembly consisted of twenty-one contigs with a total length of 751.949 bp, and annotation revealed 669 CDSs, 34 tRNAs, and 1 set of rRNA operons. The metabolic pathways analysis showed that ChTYXIII contains the complete core genes for glycolysis and a functional Sec system for protein translocation. Our phylogenomic analysis based on 133 single-copy genes and genome-to-genome metrics supports the classification as unique 'Ca. P. species' within the MPV clade. We also identified 31 putative effectors, including a homolog to SAP11 and others that have only been described in this pathogen. Our ortholog analysis revealed 37 PMU core genes in the genome of 'Ca. P. meliae' ChTYXIII, leading to the identification of 2 intact PMUs. Our work provides important genomic information for 'Ca. P. meliae' and others phytoplasmas for the 16SrXIII (MPV) group.

Insulin and the kidneys: a contemporary view on the molecular basis.

Insulin is a hormone that is composed of 51 amino acids and structurally organized as a hexamer comprising three heterodimers. Insulin is the central hormone involved in the control of glucose and lipid metabolism, aiding in processes such as body homeostasis and cell growth. Insulin is synthesized as a large preprohormone and has a leader sequence or signal peptide that appears to be responsible for transport to the endoplasmic reticulum membranes. The interaction of insulin with the kidneys is a dynamic and multicenter process, as it acts in multiple sites throughout the nephron. Insulin acts on a range of tissues, from the glomerulus to the renal tubule, by modulating different functions such as glomerular filtration, gluconeogenesis, natriuresis, glucose uptake, regulation of ion transport, and the prevention of apoptosis. On the other hand, there is sufficient evidence showing the insulin receptor's involvement in renal functions and its responsibility for the regulation of glucose homeostasis, which enables us to understand its contribution to the insulin resistance phenomenon and its association with the progression of diabetic kidney disease.

The Lambda Variant in Argentina: Analyzing the Evolution and Spread of SARS-CoV-2 Lineage C.37.

The second wave of COVID-19 occurred in South America in early 2021 and was mainly driven by Gamma and Lambda variants. In this study, we aimed to describe the emergence and local genomic diversity of the SARS-CoV-2 Lambda variant in Argentina, from its initial entry into the country until its detection ceased. Molecular surveillance was conducted on 9356 samples from Argentina between October 2020 and April 2022, and sequencing, phylogenetic, and phylogeographic analyses were performed. Our findings revealed that the Lambda variant was first detected in Argentina in January 2021 and steadily increased in frequency until it peaked in April 2021, with continued detection throughout the year. Phylodynamic analyses showed that at least 18 introductions of the Lambda variant into the country occurred, with nine of them having evidence of onward local transmission. The spatial--temporal reconstruction showed that Argentine clades were associated with Lambda sequences from Latin America and suggested an initial diversification in the Metropolitan Area of Buenos Aires before spreading to other regions in Argentina. Genetic analyses of genome sequences allowed us to describe the mutational patterns of the Argentine Lambda sequences and detect the emergence of rare mutations in an immunocompromised patient. Our study highlights the importance of genomic surveillance in identifying the introduction and geographical distribution of the SARS-CoV-2 Lambda variant, as well as in monitoring the emergence of mutations that could be involved in the evolutionary leaps that characterize variants of concern.

Omicron Waves in Argentina: Dynamics of SARS-CoV-2 Lineages BA.1, BA.2 and the Emerging BA.2.12.1 and BA.4/BA.5.

The COVID-19 pandemic has lately been driven by Omicron. This work aimed to study the dynamics of SARS-CoV-2 Omicron lineages during the third and fourth waves of COVID-19 in Argentina. Molecular surveillance was performed on 3431 samples from Argentina, between EW44/2021 and EW31/2022. Sequencing, phylogenetic and phylodynamic analyses were performed. A differential dynamic between the Omicron waves was found. The third wave was associated with lineage BA.1, characterized by a high number of cases, very fast displacement of Delta, doubling times of 3.3 days and a low level of lineage diversity and clustering. In contrast, the fourth wave was longer but associated with a lower number of cases, initially caused by BA.2, and later by BA.4/BA.5, with doubling times of about 10 days. Several BA.2 and BA.4/BA.5 sublineages and introductions were detected, although very few clusters with a constrained geographical distribution were observed, suggesting limited transmission chains. The differential dynamic could be due to waning immunity and an increase in population gatherings in the BA.1 wave, and a boosted population (for vaccination or recent prior immunity for BA.1 infection) in the wave caused by BA2/BA.4/BA.5, which may have limited the establishment of the new lineages.

Evolution of SARS-CoV-2 during the first year of the COVID-19 pandemic in Northwestern Argentina.

Studies about the evolution of SARS-CoV-2 lineages in different backgrounds such as naive populations are still scarce, especially from South America. This work aimed to study the introduction and diversification pattern of SARS-CoV-2 during the first year of the COVID-19 pandemic in the Northwestern Argentina (NWA) region and to analyze the evolutionary dynamics of the main lineages found. In this study, we analyzed a total of 260 SARS-CoV-2 whole-genome sequences from Argentina, belonging to the Provinces of Jujuy, Salta, and Tucumán, from March 31st, 2020, to May 22nd, 2021, which covered the full first wave and the early second wave of the COVID-19 pandemic in Argentina. In the first wave, eight lineages were identified: B.1.499 (76.9%), followed by N.5 (10.2%), B.1.1.274 (3.7%), B.1.1.348 (3.7%), B.1 (2.8%), B.1.600 (0.9%), B.1.1.33 (0.9%) and N.3 (0.9%). During the early second wave, the first-wave lineages were displaced by the introduction of variants of concern (VOC) (Alpha, Gamma), or variants of interest (VOI) (Lambda, Zeta, Epsilon) and other lineages with more limited distribution. Phylodynamic analyses of the B.1.499 and N.5, the two most prevalent lineages in the NWA, revealed that the rate of evolution of lineage N.5 (7.9 × 10-4 substitutions per site per year, s/s/y) was a ∼40% faster than that of lineage B.1.499 (5.6 × 10-4 s/s/y), although both are in the same order of magnitude than other non-VOC lineages. No mutations associated with a biological characteristic of importance were observed as signatures markers of the phylogenetic groups established in Northwestern Argentina, however, single sequences in non-VOC lineages did present mutations of biological importance or associated with VOCs as sporadic events, showing that many of these mutations could emerge from circulation in the general population. This study contributed to the knowledge about the evolution of SARS-CoV-2 in a pre-vaccination and without post-exposure immunization period.

First report of Xanthomonas prunicola causing bacterial leaf streaks on wheat in Argentina.

Since 2018, bacterial-like symptoms, such as leaf streaks were observed on wheat plants (Triticum aestivum L.) in Córdoba province in Argentina, with 1 to 5% of disease incidence. Samples of wheat stem and spike collected in a trial of varieties for summer/autumn sowing in the experimental field of the INTA Marcos Juárez were disinfected, washed and macerated in mortars with sterile distilled water and extracts were streaked on Luria-Bertani (LB) agar. After 48 h incubation at 28 °C, circular, mucoid, convex, and cream colonies were observed and pure cultures were transferred to LB medium for further identification tests. Biochemical tests corroborated the detection of a Gram-negative bacillus. Conventional PCR was performed using DNA isolate from pure cultures and general primers for various species of genera Xanthomonas (Maes 1993) and Pseudomonas (Mulet et al. 2010). An isolate (Arg-1), with cream colored colonies was positive using general primers for Xanthomonas sp (amplified fragment of 444 bp). A bacterial suspension containing 108 CFU mL-1 grown for 48 h on LB medium at 28 °C was injected into three-week-old leaves of wheat plants to fulfill Koch's postulates. After 5 days, plants showed symptoms of chlorosis, streaks and then necrosis on the leaves. The bacteria were re-isolated from the inoculated plants, showing same symptoms observed in the original plants. Negative control plants, inoculated with sterile water remained without symptoms. The amplified 444 bp fragment described above was sequenced by the Sanger method (GenBank accession OM972662), as well as another 757 bp fragment amplified with universal primers that amplify the partial 16S rDNA gene (GenBank accession OM972661). Analyses of these sequences, as well as the protein profile of the isolate obtained by matrix assisted laser desorption/ionization time of-flight mass spectrometry (MALDI-TOF MS) Bruker Biotyper, allowed to identify only the genus Xanthomonas. With the purpose of determine the species status, the complete genome of isolate Arg-1 was sequenced using Oxford Nanopore Technologies (ONT). Total gDNA was isolate from pure cultures using a commercial kit (Wizard Genomic DNA Purification Kit, Promega). gDNA library was constructed using Ligation Sequencing Kit (SQK-LSK109) and sequenced using ONT platform on a MinION 1kb device. Raw basecalled sequences were filtered using Filtlong and assembled using Trycycler. The genome was assembled in a single contig comprising 5.410.641 bp with 4740 predicted CDSs and 63.9% GC content. Genome sequence was deposited in GenBank under accession number CP094827 and SRA data SRX14635308. Whole-genome Average Nucleotide Identity (ANI) analysis showed values of ~ 97% against the reference genomes of Xanthomonas prunicola (PHKX01.1, PHKV01.1 and PHKW01.1) and 100% in complete 16S rRNA gene sequences (1547 bp). These findings suggest that a new wheat pathogen within the genus Xanthomonas is present in Argentina, as well as was reported in Uruguay and USA (Clavijo et al. 2021). To our knowledge, this is the first report of X. prunicola affecting wheat in Argentina and the first complete genome registered for this specie. Accurate and specific diagnostics are required for the detection of X. prunicola in wheat crops to implement correct prevention and control strategies to this disease, avoiding the dissemination in lots where it has not yet been found.

Cost-Effective Method to Perform SARS-CoV-2 Variant Surveillance: Detection of Alpha, Gamma, Lambda, Delta, Epsilon, and Zeta in Argentina.

SARS-CoV-2 variants with concerning characteristics have emerged since the end of 2020. Surveillance of SARS-CoV-2 variants was performed on a total of 4,851 samples from the capital city and 10 provinces of Argentina, during 51 epidemiological weeks (EWs) that covered the end of the first wave and the ongoing second wave of the COVID-19 pandemic in the country (EW 44/2020 to EW 41/2021). The surveillance strategy was mainly based on Sanger sequencing of a Spike coding region that allows the identification of signature mutations associated with variants. In addition, whole-genome sequences were obtained from 637 samples. The main variants found were Gamma and Lambda, and to a lesser extent, Alpha, Zeta, and Epsilon, and more recently, Delta. Whereas, Gamma dominated in different regions of the country, both Gamma and Lambda prevailed in the most populated area, the metropolitan region of Buenos Aires. The lineages that circulated on the first wave were replaced by emergent variants in a term of a few weeks. At the end of the ongoing second wave, Delta began to be detected, replacing Gamma and Lambda. This scenario is consistent with the Latin American variant landscape, so far characterized by a concurrent increase in Delta circulation and a stabilization in the number of cases. The cost-effective surveillance protocol presented here allowed for a rapid response in a resource-limited setting, added information on the expansion of Lambda in South America, and contributed to the implementation of public health measures to control the disease spread in Argentina.

Draft Genome Sequence of "Candidatus Phytoplasma pruni" (X-Disease Group, Subgroup 16SrIII-B) Strain ChTDIII from Argentina.

Herein, we report the draft genome sequence of "Candidatus Phytoplasma pruni" strain ChTDIII (subgroup 16SrIII-B). The final assembly consists of 790,517 nucleotides organized in 67 contigs (minimal size, 1 kb), with a G+C content of 29.4% and encoding 672 proteins.

Phytoplasmas diversity and identification of new aster yellows subgroup (16SrI) associated with weed species in Argentina.

Symptoms of phytoplasma infection were observed in different weed species, Bidens subalternans, Conyza bonariensis, Heterosperma ovatifolium and Conium maculatum, collected from diverse geographical regions in Argentina. To confirm the association of phytoplasma infection with symptomatic plants, PCR, RFLP and phylogenetic analyses based on 16S rRNA-encoding sequences were performed. In this work, we report the presence of phytoplasmas from group 16SrVII (subgroup 16VII-B) infecting C. bonariensis and B. subalternans and from group 16SrIII (subgroup 16SrIII-X) B. subalternans, H. ovatifolium, and C. maculatum. Phytoplasmas from the aster yellows group were detected infecting C. bonariensis and B. subalternans. Analysis of 16S rRNA-encoding genes revealed the presence of two distinct operons, rrnB (16SrI-B) and newly described rrnA, which is different from the reference RFLP patterns of all previously established 16SrI-subgroups. A single rp operon sequence analysis reveals the presence of simple infection and confirms a description of a novel subgroup. On the basis of these results we propose a designation of new subgroup 16SrI-(B/AJ) AJ (rp-AJ). To our knowledge, this is the first report of phytoplasmas infecting Bidens subalternans¸ Heterosperma ovatifolium and Conium maculatum.

Identification of three novel subgroups within the X-disease group phytoplasma associated with strawberry redness disease.

Strawberry plants showing symptoms of lethal redness disease were found in production fields located in Tucumán province, Argentina. The presence of phytoplasmas was confirmed by PCR of 16S rDNA gene using phytoplasma universal primers. According to the 16S rDNA gene sequence identity, the four isolates analysed are related to the X-disease group (16SrIII) (identity ~99 %). These results were confirmed by in silico RFLP, actual RFLP and also by phylogenetic analyses of the 16S rDNA gene. This new phytoplasma was named as Strawberry X-Redness (StrawXR). The results from virtual and actual RFLP analyses of 16S rDNA gene revealed the presence of subgroup 16SrIII-J and three new 16SrIII subgroups. This is the first record of phytoplasmas from X-disease group associated strawberry in Argentina. These results confirm the prevalence of X-disease group and also contribute to the knowledge of diversity of phytoplasmas in this region.

Description of 'Candidatus Phytoplasma meliae', a phytoplasma associated with Chinaberry (Melia azedarach L.) yellowing in South America.

China tree yellows (ChTY) phytoplasma is associated with the yellowing disease of the China tree (Melia azedarach) in Argentina. According to partial 16S rRNA gene analysis, ChTY phytoplasma belongs to the 16Sr XIII group, subgroup G. Strains of species of ChTY have 98-99 % 16S rDNA gene sequence similarity with 16SrXIII-group phytoplasmas, and less than 97.5 % when compared to all 'CandidatusPhytoplasma' described so far, except for the novel 'CandidatusPhytoplasma hispanicum'. However, strains of species of ChTY are differentiated from the latter due to having additional molecular and biological attributes. The presence of unique features in the 16S rDNA sequence distinguishes ChTY from all species of 'CandidatusPhytoplasma' currently described. The in silico RFLP profile of 16S rDNA (1.2 kb) and rpLV-rpsC (1.3 kb) genes distinguished ChTY, as in the 16SrXIII-G subgroup within the 16SrXIIII group. The phylogenetic analyses, based on 16S rDNA, rpLV-rpsC and secA gene sequences, in addition to the restricted host range, characteristic symptoms and geographical distribution, confirm that the collective strains of the species ChTY represent a distinct lineage within the phytoplasma clade and support the description of a novel species of 'CandidatusPhytoplasma meliae' with the reference strain being ChTY-Mo3 (Montecarlo, Argentina).

Detection and identification of a novel 16SrXIII subgroup phytoplasma associated with strawberry red leaf disease in Argentina.

Strawberry red leaf phytoplasma was found in strawberry plants from production fields in Lules (Tucumán province) and Bella Vista (Corrientes province), Argentina. Characteristic strawberry red leaf symptoms were stunting, young leaves with yellowing at the edges, mature leaves which curled and were reddish at the abaxial face, flower and fruit deformation and death. The pathogen was detected with phytoplasma-universal primer pairs P1/P7 followed by R16F2n/R16R2 as nested primers in 13 diseased plants. Based on RFLP and sequence analysis of the amplified 16S rRNA gene, the phytoplasma was related to the 16SrXIII group (Mexican periwinkle virescence). In silico the RFLP profile of all the samples analysed revealed the presence of a unique pattern, showing that the novel phytoplasma is different from all the phytoplasmas currently composing the 16SrXIII group. The phylogenetic analysis was consistent with RFLP analysis as the strawberry red leaf phytoplasma was grouped within the 16SrXIII group, but formed a particular cluster. On this basis, the Strawberry red leaf phytoplasma associated with strawberry red leaf disease was assigned to a new subgroup, 16SrXIII-F.

[Cardiovascular risk factors among 7-and 14-year old schoolchildren in Cartagena, Colombia, 2009]. / Factores de riesgo cardiovascular en escolares entre 7 y 14 años en Cartagena, Colombia, 2009.

OBJECTIVE: Identifying family history, dyslipidaemia, hyperglycaemia, low physical activity and being overweight or suffering from obesity as cardiovascular risk factors in children aged 7 to 14 years in Cartagena, 2009. MATERIALS AND METHODS: A descriptive study of 173 children from Cartagena, Colombia, was designed. Biochemical serum parameters were determined by spectrophotometric methods. Habits were investigated through interviews and altered body weight was established using the body mass index (BMI). RESULTS: The sample consisted of 87 girls and 86 boys, and mean age was 9.9 years (9.6-10.3, 95 % CI). 75.1% (68.7-81.5, 95 % CI) had a family history of being overweight; 2.3 % (0.1-4.5, 95 % CI) were overweight and 1.7 % (0.0-3.6 95 %CI) were obese. More than half of the children had hightotal cholesterol levels (53.2 %; 45.8-60.695 %CI) and LDL (57.2 %; 49.8-64.6 95 % CI). Non-HDL cholesterol was found to be increased by 46.8 % (39.4-54.2 95 % CI). There was a significant difference between genders for triglyceridemia (females: 94.1 mg/dL; 87.0-101.2 mg/dL 95 % CI; males: 81.7 mg/dL; 75.0-88.5 mg/dL 95 % CI; p=0.005) and low physical activity (females: 83.8 %; 73.5-94.5 % 95 % CI; males: 44.2 %; 45.4-66.6 % 95 % CI; p=0,0001). CONCLUSIONS: Cardiovascular risk factors in these schoolchildren, even in those who were not obese, justify the need for the early detection of these factors as well as their strict controlto reduce their impact on people's future quality of life.

Factores de riesgo cardiovascular en escolares entre 7 y 14 años en Cartagena, Colombia, 2009 / Cardiovascular risk factors among 7-and 14-year old schoolchildren in Cartagena, Colombia, 2009

Objetivo Identificar antecedentes familiares, dislipidemias, hiperglucemia, escasa actividad física y sobrepeso u obesidad como factores de riesgo cardiovascular en niños entre 7 y 14 años de Cartagena, 2009. Materiales y Métodos Se realizó un estudio descriptivo en 173 niños de Cartagena, Colombia. Se determinaron los parámetros bioquímicos en suero mediante técnicas espectrofotométricas. Los hábitos fueron indagados mediante entrevista y las alteraciones de peso fueron establecidas utilizando el índice de masa corporal. Resultados La muestra quedó conformada por 87 niñas y 86 niños con edad promedio de 9,9 años (IC95 por ciento 9,6-10,3). El 75,1 por ciento (IC95 por ciento 68,7-81.5) presentaron antecedentes familiares; 2,3 por ciento (IC95 por ciento 0,1-4,5) tuvieron sobrepeso y 1,7 por ciento (IC95 por ciento 0,0-3,6) obesidad. Más de la mitad de los niños presentaron niveles elevados de colesterol total (53,2 por ciento; IC95 por ciento 45,8-60,6) y LDL (57,2 por ciento; IC95 por ciento 49,8-64,6). El colesterol no HDL se halló incrementado en el 46,8 por ciento (IC95 por ciento 39,4-54,2). Las niñas presentaron mayor concentración de triglicéridos (94,1 mg/dL; IC95 por ciento 93,0-95,2 mg/dL) que los niños (81,7 mg/dL; IC95 por ciento 80,6-82,8 mg/dL) con diferencia significativa (p=0,005) y también presentaron con mayor frecuencia baja actividad física (niñas: 83,8 por ciento; IC95 por ciento 73,5-94,5 por ciento; varones: 44,2 por ciento; IC95 por ciento 45,4-66,6; p=0,0001). Conclusión Los factores de riesgo cardiovascular presentes en esta población, inclusive en ausencia de obesidad, muestran la necesidad de implementar programas que los identifiquen e intervengan de manera oportuna para disminuir su impacto en la calidad de vida futura.

Objective Identifying family history, dyslipidaemia, hyperglycaemia, low physical activity and being overweight or suffering from obesity as cardiovascular risk factors in children aged 7 to 14 years in Cartagena, 2009. Materials and Methods A descriptive study of 173 children from Cartagena, Colombia, was designed. Biochemical serum parameters were determined by spectrophotometric methods. Habits were investigated through interviews and altered body weight was established using the body mass index (BMI). Results The sample consisted of 87 girls and 86 boys, and mean age was 9.9 years (9.6-10.3, 95 percent CI). 75.1 percent (68.7-81.5, 95 percent CI) had a family history of being overweight; 2.3 percent (0.1-4.5, 95 percent CI) were overweight and 1.7 percent (0.0-3.6 95 percentCI) were obese. More than half of the children had hightotal cholesterol levels (53.2 percent; 45.8-60.695 percentCI) and LDL (57.2 percent; 49.8-64.6 95 percent CI). Non-HDL cholesterol was found to be increased by 46.8 percent (39.4-54.2 95 percent CI). There was a significant difference between genders for triglyceridemia (females: 94.1 mg/dL; 87.0-101.2 mg/dL 95 percent CI; males: 81.7 mg/dL; 75.0-88.5 mg/dL 95 percent CI; p=0.005) and low physical activity (females: 83.8 percent; 73.5-94.5 percent 95 percent CI; males: 44.2 percent; 45.4-66.6 percent 95 percent CI; p=0,0001). Conclusions Cardiovascular risk factors in these schoolchildren, even in those who were not obese, justify the need for the early detection of these factors as well as their strict controlto reduce their impact on people's future quality of life.

Viabilidade da antecipação do tratamento de sementes de arroz com inseticidas em relação à data de semeadura no controle de Oryzophagus oryzae (Coleoptera: Curculionidae)

Oryzophagus oryzae (Costa Lima, 1936) is one of the most important pests of irrigated rice, whose control is made traditionally with granulated insecticides on the irrigation water. However, the use of insecticides on the seeds has been considered a promising method. Although there are adequate implements to apply insecticides on the seeds, its hard to make this treatment with quality and in a big quantity, few days or hours before sowing. In this context, the viability of treat the rice seeds in an advance of sowing date has been evaluated. Two experiments were performed at Embrapa Clima Temperado, Capão do Leão, RS, Brazil in 1997/98 and 2004/05. The experimental design was in blocks at random with four repetitions, being evaluated the insecticides carbosulfan and fipronil applied manually to the seeds of rice in different times that preceded the sowing. Germination power and vigour, emerged plants, larval population and grains productivity were considered. The rice seeds treatment with insecticides in advance of sowing date trying to achieve the control of O. oryzae, demonstrate viability. The insecticides carbosulfan and fipronil are adequate to advance seeds treatment, if applied until 75 days before sowing.

Oryzophagus oryzae (Costa Lima, 1936) é uma das pragas mais prejudiciais da cultura do arroz irrigado, sendo seu controle efetuado tradicionalmente com inseticidas granulados aplicados na água de irrigação. No entanto, o uso de inseticidas aplicados às sementes tem sido considerado promissor. Embora existam máquinas adequadas para aplicação de inseticidas às sementes, há dificuldade de assegurar a qualidade das sementes tratadas, em poucos dias ou mesmo horas antes da semeadura. Assim, objetivou-se avaliar a viabilidade do tratamento de sementes de arroz com inseticidas aplicados com antecedência à data de semeadura para o controle de O. oryzae. Dois experimentos foram instalados na Estação Experimental de Terras Baixas da Embrapa Clima Temperado, localizada no município de Capão do Leão, Rio Grande do Sul (RS), em duas épocas (1997/1998 e 2004/2005). O delineamento experimental foi em blocos ao acaso com quatro repetições. Foram avaliados os inseticidas carbosulfano e fipronil aplicados manualmente às sementes de arroz em diferentes épocas que antecederam a semeadura e foram avaliadas as variáveis poder germinativo e vigor das sementes, plantas emergidas, população larval e produtividade de grãos. O tratamento das sementes de arroz com inseticidas, antecipadamente à data de semeadura, visando ao controle de O. oryzae, demonstrou ser viável. Os inseticidas carbosulfano e fipronil são adequados ao tratamento antecipado das sementes, se aplicados até 75 dias antes da semeadura.

Viabilidade da antecipação do tratamento de sementes de arroz com inseticidas em relação à data de semeadura no controle de Oryzophagus oryzae (Coleoptera: Curculionidae)

Oryzophagus oryzae (Costa Lima, 1936) is one of the most important pests of irrigated rice, whose control is made traditionally with granulated insecticides on the irrigation water. However, the use of insecticides on the seeds has been considered a promising method. Although there are adequate implements to apply insecticides on the seeds, it’s hard to make this treatment with quality and in a big quantity, few days or hours before sowing. In this context, the viability of treat the rice seeds in an advance of sowing date has been evaluated. Two experiments were performed at Embrapa Clima Temperado, Capão do Leão, RS, Brazil in 1997/98 and 2004/05. The experimental design was in blocks at random with four repetitions, being evaluated the insecticides carbosulfan and fipronil applied manually to the seeds of rice in different times that preceded the sowing. Germination power and vigour, emerged plants, larval population and grains productivity were considered. The rice seeds treatment with insecticides in advance of sowing date trying to achieve the control of O. oryzae, demonstrate viability. The insecticides carbosulfan and fipronil are adequate to advance seeds treatment, if applied until 75 days before sowing.

Oryzophagus oryzae (Costa Lima, 1936) é uma das pragas mais prejudiciais da cultura do arroz irrigado, sendo seu controle efetuado tradicionalmente com inseticidas granulados aplicados na água de irrigação. No entanto, o uso de inseticidas aplicados às sementes tem sido considerado promissor. Embora existam máquinas adequadas para aplicação de inseticidas às sementes, há dificuldade de assegurar a qualidade das sementes tratadas, em poucos dias ou mesmo horas antes da semeadura. Assim, objetivou-se avaliar a viabilidade do tratamento de sementes de arroz com inseticidas aplicados com antecedência à data de semeadura para o controle de O. oryzae. Dois experimentos foram instalados na Estação Experimental de Terras Baixas da Embrapa Clima Temperado, localizada no município de Capão do Leão, Rio Grande do Sul (RS), em duas épocas (1997/1998 e 2004/2005). O delineamento experimental foi em blocos ao acaso com quatro repetições. Foram avaliados os inseticidas carbosulfano e fipronil aplicados manualmente às sementes de arroz em diferentes épocas que antecederam a semeadura e foram avaliadas as variáveis poder germinativo e vigor das sementes, plantas emergidas, população larval e produtividade de grãos. O tratamento das sementes de arroz com inseticidas, antecipadamente à data de semeadura, visando ao controle de O. oryzae, demonstrou ser viável. Os inseticidas carbosulfano e fipronil são adequados ao tratamento antecipado das sementes, se aplicados até 75 dias antes da semeadura.

Plataformas de colheita e colheita manual com trilha mecânica sobre a qualidade de sementes de arroz ( Oryza sativa, L. )

During irrigated rice harvesting occur losses and physical and phisiological seed damage. Late 80's, appeared the strippers headers that strip the grain, instead of cutting the spike. However, little is know about physical and phisiological seed damage by harvest header. The objective of this work was to evaluate the mechanical damage caused to BR-IRGA 409 and BR-IRGA 410 rice cultivars by three harvesting methods: (a) manual harvesting and mechanical strip; (b) cutterbar harvesting and; (c) stripper header harvesting. Samples were collected directly in the grain tank when the harvest was mechanical. The experimental design was randomized blocks with six replications. Results demonstrated that the rice seeds of the studied variety didn't showed significant differences in physical and phisiological in seed quality when harvested by cutterbar or stripper header. These two harvesting forms, however, showed significantly seed damages when compared to manual harvesting and mechanical strip.

Durante a colheita do arroz irrigado ocorrem perdas e danos físicos e fisiológicos às sementes. No final da década de oitenta, surgiram as plataformas recolhedoras, que retiram ou arrancam o grão ao invés de cortar a panícula, porém, pouco se conhece a respeito dos danos físicos e fisiológicos que este sistema de plataforma pode causar às sementes. Este trabalho teve por objetivo avaliar os danos mecânicos causados às sementes dos cultivares de arroz BR-IRGA 409 e BR-IRGA 410, por três formas de colheita: (a) colheita manual e trilha mecânica; (b) colheita com plataforma de corte; (c) colheita com plataforma recolhedora. Quando a colheita foi mecânica, realizou-se a coleta das amostras diretamente no graneleiro. O delineamento experimental foi blocos ao acaso, com seis repetições. Os resultados demonstraram que as sementes de arroz irrigado dos cultivares estudados não apresentaram diferenças significativas em suas qualidades físicas e fisiológicas, quando colhidas com plataforma de corte e com a plataforma recolhedora. Estes dois métodos de colheita, porém, apresentaram danos significativamente maiores quando comparados à colheita manual e trilha mecânica.

Plataformas de colheita e colheita manual com trilha mecânica sobre a qualidade de sementes de arroz ( Oryza sativa, L. )

During irrigated rice harvesting occur losses and physical and phisiological seed damage. Late 80's, appeared the strippers headers that strip the grain, instead of cutting the spike. However, little is know about physical and phisiological seed damage by harvest header. The objective of this work was to evaluate the mechanical damage caused to BR-IRGA 409 and BR-IRGA 410 rice cultivars by three harvesting methods: (a) manual harvesting and mechanical strip; (b) cutterbar harvesting and; (c) stripper header harvesting. Samples were collected directly in the grain tank when the harvest was mechanical. The experimental design was randomized blocks with six replications. Results demonstrated that the rice seeds of the studied variety didn't showed significant differences in physical and phisiological in seed quality when harvested by cutterbar or stripper header. These two harvesting forms, however, showed significantly seed damages when compared to manual harvesting and mechanical strip.

Durante a colheita do arroz irrigado ocorrem perdas e danos físicos e fisiológicos às sementes. No final da década de oitenta, surgiram as plataformas recolhedoras, que retiram ou arrancam o grão ao invés de cortar a panícula, porém, pouco se conhece a respeito dos danos físicos e fisiológicos que este sistema de plataforma pode causar às sementes. Este trabalho teve por objetivo avaliar os danos mecânicos causados às sementes dos cultivares de arroz BR-IRGA 409 e BR-IRGA 410, por três formas de colheita: (a) colheita manual e trilha mecânica; (b) colheita com plataforma de corte; (c) colheita com plataforma recolhedora. Quando a colheita foi mecânica, realizou-se a coleta das amostras diretamente no graneleiro. O delineamento experimental foi blocos ao acaso, com seis repetições. Os resultados demonstraram que as sementes de arroz irrigado dos cultivares estudados não apresentaram diferenças significativas em suas qualidades físicas e fisiológicas, quando colhidas com plataforma de corte e com a plataforma recolhedora. Estes dois métodos de colheita, porém, apresentaram danos significativamente maiores quando comparados à colheita manual e trilha mecânica.