BACKGROUND Trypanosoma cruzi shows an exuberant genetic diversity. Currently, seven phylogenetic lineages, called discrete typing units (DTUs), are recognised: TcI-TcVI and Tcbat. Despite advances in studies on T. cruzi and its populations, there is no consensus regarding its heterogeneity. OBJECTIVES This study aimed to perform molecular characterisation of T. cruzi strains, isolated in the state of São Paulo, to identify the DTUs involved and evaluate their genetic diversity. METHODS T. cruzi strains were isolated from biological samples of chronic chagasic patients, marsupials and triatomines through culture techniques and subjected to molecular characterisation using the fluorescent fragment length barcoding (FFLB) technique. Subsequently, the results were correlated with complementary information to enable better discrimination between the identified DTUs. FINDINGS It was possible to identify TcI in two humans and two triatomines; TcII/VI in 19 humans, two marsupials and one triatomine; and TcIII in one human host, an individual that also presented a result for TcI, which indicated the possibility of a mixed infection. Regarding the strains characterised by the TcII/VI profile, the correlation with complementary information allowed to suggest that, in general, these parasite populations indeed correspond to the TcII genotype. MAIN CONCLUSIONS The TcII/VI profile, associated with domestic cycles and patients with chronic Chagas disease, was the most prevalent among the identified DTUs. Furthermore, the correlation of the study results with complementary information made it possible to suggest that TcII is the predominant lineage of this work.

RESUMO Este estudo foi realizado com o objetivo de avaliar a incidência de Fusarium spp. em híbridos comerciais de milho e manejos de irrigação por pivô central em segunda safra. O experimento foi conduzido em delineamento de blocos casualizados em esquema de parcelas subdivididas, sendo as parcelas constituídas pelos manejos de irrigação com cinco frequências (1, 2, 3, 4, 5 dias, primeiro experimento) e cinco lâminas d’água (25, 50, 75, 100 e 125% da evapotranspiração da cultura) e as subparcelas com cinco híbridos de milho (2B810, MG580, AS1633, DKB290 e AG8544), em quatro repetições. Foram avaliadas altura de planta, altura de inserção de espigas, umidade no momento da colheita, produtividade e incidência de podridão no colmo. Tanto as a frequências de irrigação como as lâminas de irrigação não influenciaram a incidência da doença. A frequência de irrigação de um dia proporcionou o maior rendimento de híbridos de milho. O híbrido 2B810 apresentou o maior rendimento e a menor incidência da doença.

ABSTRACT This study aimed to verify the incidence of Fusarium spp. in commercial maize hybrids and irrigation management strategies utilizing center pivot systems. The experiment was carried out during the second season in a randomized block design with a split-plot arrangement with five maize hybrids (2B810, MG580, AS1633, DKB290, and AG8544). The plots were irrigated with five frequencies (1, 2, 3, 4, and 5 days) in one experiment, and five water depths (at 25, 50, 75, 100, and 125% of crop evapotranspiration) in another experiment. Plant height, ear insertion height, moisture at harvest time, yield, and incidence of stalk rot were evaluated. Neither irrigation frequency nor irrigation depth influenced the incidence of disease. The one-day irrigation frequency provided the highest yield for maize hybrids. Hybrid 2B810 showed the highest yield and the lowest incidence of the disease.

RESUMO A redução da área foliar afeta drasticamente a produtividade do milho, em função da sua baixa plasticidade. Assim, aplicação adequada de água pode minimizar este problema, tendo em vista que, em condições hídricas favoráveis, a planta expressaria seu potencial máximo de produção. Avaliou-se a influência da irrigação no desempenho produtivo do milho doce submetido a diferentes níveis de desfolha no início do ciclo da cultura. O delineamento experimental foi em blocos casualizados em esquema de parcelas subdivididas, tendo nas parcelas quatro lâminas de irrigação [50, 75, 100 e 125% da evapotranspiração da cultura (ETc)] e nas subparcelas três níveis de desfolha [0% (testemunha); 35% (remoção de quatro folhas completamente expandidas); 100% (remoção total das folhas, secção da parte aérea)], com três repetições. O emprego de irrigação apresenta influência positiva na recuperação de danos ocasionados por desfolha em estágios iniciais de desenvolvimento do milho doce, sendo que, o sucesso no manejo da irrigação como estratégia para atenuar os prejuízos ocasionados pela desfolha, depende do nível da área foliar perdida e da lâmina de água empregada.

ABSTRACT Reduction of leaf area significantly affects maize productivity, due to its low plasticity. Thus, appropriate water application can minimize this problem, considering that under favorable water conditions the plant would express its maximum production potential. The aim of this study was to evaluate the influence of irrigation on the productive performance of sweet corn submitted to different defoliation levels at the beginning of crop cycle. The experimental design was a randomized block design, arranged in split plot scheme; plots consisting of four water depths [50, 75, 100 and 125% of crop evapotranspiration (ETc)] and the subplots consisted of three defoliation levels [0% (control); 35% (removal of four fully expanded leaves), 100% (total removal of leaves, shoot section)], with three replicates. The use of irrigation has a positive influence on recovery of damages caused by defoliation at the initial development stages of sweet corn, and the success of irrigation management, as a strategy to mitigate damages caused by defoliation, depends on the level of the lost leaf area and the amount of water used.

ABSTRACT The sizing of mechanized agricultural systems depends on the soil and climatic conditions, the crop and the work regime. The aim of this study was to determine the probabilities of time available during an agricultural year for mechanized spraying and sowing in the northeast region of the State of Mato Grosso do Sul and south of Goiás. The meteorological restrictions imposed as unfavorable hours were: ambient temperature above 32°C, relative air humidity below 50%, wind velocity above 15 km h-1 and soil volumetric moisture above 39% (humidity equivalent to 90% of the available water capacity for the studied soil). The mathematical models were elaborated for eight years, based on the historical data of the automatic station of the National Institute of Meteorology installed in the region. It was possible to determine the time available for mechanized sowing and agricultural spraying operations. The available times for every ten days of the agricultural year for mechanized spraying and sowing in the study region were determined. The hourly water balance is used for the restrictive study of soil moisture in determining the time available for mechanized operations. A single self-propelled sprayer (30 m bar) and a single seed drill (48 rows) are not sufficient to meet the operational rate in an area of 3,000 ha in the northeast of the state of Mato Grosso do Sul and south of Goiás.

RESUMO As reduções de produção de soja no Brasil estão ligadas principalmente à ocorrência de veranicos, os quais estão cada vez mais frequentes devido às mudanças climáticas. Sendo assim, objetivou-se com este trabalho avaliar diferentes lâminas de irrigação em cultivares de soja irrigadas em pivô central. O trabalho foi realizado no ano agrícola 2014/15, no município de Chapadão do Sul, MS. O delineamento foi em blocos casualizados em esquema de parcelas subdivididas com quatro repetições, onde as parcelas constaram de 4 lâminas de irrigação (0, 50, 75 e 100% da Evapotranspiração da Cultura - ETc), e as subparcelas de 6 cultivares de soja (NA 5909 RR, DM 5958 IPRO, Anta 82 RR, M 7110 IPRO, Desafio RR, M 7739 IPRO). A cultivar Desafio RR foi a que mais respondeu à irrigação, alcançando produtividade de 6174 kg ha-1 com a reposição de 50% da ETc, contra 3798 kg ha-1 na condição de sequeiro. A maior produtividade no sequeiro foi com a cultivar Na 5909 RR, chegando a 4806 kg ha-1, indicando que a resposta da cultura à irrigação está relacionada principalmente às características genéticas de cada cultivar.

ABSTRACT Reductions in soybean yields are mainly linked to the occurrence of dry spells, which are becoming more frequent due to climate change. Thus, the aim of this study was to evaluate soybean cultivars irrigated with different water depths under center pivot. The experiment was conducted during the 2014/15 growing season, under center-pivot irrigation in Chapadão do Sul, MS, Brazil. The design was a randomized block in split plot with four replicates, where plots consisted of 4 water depths (0, 50, 75 and 100% of crop evapotranspiration - ETc) and the subplots of 6 soybean cultivars (NA 5909 RR, DM 5958 IPRO, Anta 82 RR, M 7110 IPRO, Desafio RR, M 7739 IPRO). The cultivar Desafio RR was the one that best responded to irrigation, increasing yield to 6174 kg ha-1 against 3798 kg ha-1 under rainfed condition. The highest yield under rainfed condition was obtained by the cultivar NA 5909 RR, reaching 4806 kg ha-1. This shows that some cultivars can respond positively to irrigation, resulting in increased yield, depending on the genetic characteristics of each one.

ABSTRACT Symptomatic forms of toxoplasmosis are a serious public health problem and occur in around 10-20% of the infected people. Aiming to improve the molecular diagnosis of symptomatic toxoplasmosis in Brazilian patients, this study evaluated the performance of real time PCR testing two primer sets (B1 and REP-529) in detecting Toxoplasma gondii DNA. The methodology was assayed in 807 clinical samples with known clinical diagnosis, ELISA, and conventional PCR results in a 9-year period. All samples were from patients with clinical suspicion of several features of toxoplasmosis. According to the minimum detection limit curve (in CT), REP-529 had greater sensitivity to detect T. gondii DNA than B1. Both primer sets were retrospectively evaluated using 515 DNA from different clinical samples. The 122 patients without toxoplasmosis provided high specificity (REP-529, 99.2% and B1, 100%). From the 393 samples with positive ELISA, 146 had clinical diagnosis of toxoplasmosis and positive conventional PCR. REP-529 and B1 sensitivities were 95.9% and 83.6%, respectively. Comparison of REP-529 and B1 performances was further analyzed prospectively in 292 samples. Thus, from a total of 807 DNA analyzed, 217 (26.89%) had positive PCR with, at least one primer set and symptomatic toxoplasmosis confirmed by clinical diagnosis. REP-529 was positive in 97.23%, whereas B1 amplified only 78.80%. After comparing several samples in a Brazilian referral laboratory, this study concluded that REP-529 primer set had better performance than B1 one. These observations were based after using cases with defined clinical diagnosis, ELISA, and conventional PCR.

ABSTRACT Planting density can influence the competitiveness among plants mainly by water, nutrients and solar radiation, directly affecting yield. The purpose of this study was to evaluate the productivity of different soybean cultivars at different planting populations under irrigated and rainfed conditions. The experiment was conducted during the 2014/15 growing season, under center pivot irrigation in Chapadão do Sul – MS, Brazil. The experimental design was randomized complete block design with split-plot, as follows: Irrigated and Rainfed (plots) x Six cultivars (subplots) x Three Plant Populations (sub-subplots) with 4 replications. The irrigation management was realized by Penman-Monteith-FAO method. The cultivars used were: NA 5909 RR, DM 5958 IPRO, Anta 82 RR, M 7110 IPRO, Desafio RR and M 7739 IPRO. Populations indicated by the holders of the seeds were tested, and also population 20% above and 20% below with the hypothesis that in different humidity conditions, different cultivars may have different answers depending on their populations. In rainfed condition productivity and mass of one hundred grains were influenced by water deficit. Cultivar Desafio RR presented the best performance under irrigation, with productivity of 6174 kg ha−1.

O presente estudo foi realizado no Instituto Agronômico do Paraná (IAPAR), em Londrina, Estado do Paraná (latitude de 23º18'S, longitude de 51º09'W e altitude média de 585 m). O clima local, segundo a classificação do Köppen, é do tipo Cfa, ou seja, subtropical úmido, com chuvas em todas as estações, podendo ocorrer secas no período de inverno. Determinou-se a evaporação (E) da água do solo sob diferentes densidades de cobertura com resíduo da cultura de trigo. Os tratamentos foram instalados em lisímetros de pesagem de 2,66 m² e 1,3 m de profundidade, que permitem determinar E por diferença de massa com precisão equivalente a 0,1 mm em intervalos de uma hora. Os tratamentos consistiram em 0; 2,5; 5 e 10 t ha-1 de resíduos da cultura do trigo, colocadas de forma homogênea em cada lisímetro. No primeiro ciclo (22/09 a 20/10/2008), a redução de E em relação ao solo descoberto foi de 4; 15 e 24%, enquanto no segundo ciclo (01/12 a 30/12/2008), a redução foi de 15; 22 e 25%, respectivamente, para os tratamentos 2,5; 5 e 10 t ha-1.

This study was conducted at the Agronomic Institute of Paraná (IAPAR) in Londrina, State of Paraná (PR), Brazil (latitude 23º18'S, longitude 51º09'W and average altitude of 585 m). The local climate, according to the classification of Köeppen, is Cfa type, i.e., humid subtropical climate, with rain in all seasons and can occur dry seasons during the winter. It was determined soil evaporation (E) under different coverage densities with residue from the wheat crop. The treatments were installed in weighting lysimeters of 2.66 m² and 1.3 m deep, which allows to determine E by the mass difference with measuring precision of 0.1mm at one hour intervals. Treatments consisted of 0; 2.5; 5 and 10 t ha-1 of wheat crop residues, placed evenly over each lysimeter. In the first cycle (September 22nd to October 20th, 2008), the reduction of E, as compared to a bare soil, was 4; 15 and 24%, while in the second cycle (December 1st to 30th, 2008), the reduction was of 15; 22 and 25%, respectively, for the treatments of 2.5; 5 and 10 t ha-1.