Effects of traffic control on the soil physical quality and the cultivation of sugarcane

The cultivation of sugarcane with intensive use of machinery, especially for harvest, induces soil compaction, affecting the crop development. The control of agricultural traffic is an alternative of management in the sector, with a view to preserve the soil physical quality, resulting in increased sugarcane root growth, productivity and technological quality. The objective of this study was to evaluate the physical quality of an Oxisol with and without control traffic and the resulting effects on sugarcane root development, productivity and technological quality. The following managements were tested: no traffic control (NTC), traffic control consisting of an adjustment of the track width of the tractor and sugarcane trailer (TC1) and traffic control consisting of an adjustment of the track width of the tractor and trailer and use of an autopilot (TC2). Soil samples were collected (layers 0.00-0.10; 0.10-0.20 and 0.20-0.30 m) in the plant rows, inter-row center and seedbed region, 0.30 m away from the plant row. The productivity was measured with a specific weighing scale. The technological variables of sugarcane were measured in each plot. Soil cores were collected to analyze the root system. In TC2, the soil bulk density and compaction degree were lowest and total porosity and macroporosity highest in the plant row. Soil penetration resistance in the plant row, was less than 2 MPa in TC1 and TC2. Soil aggregation and total organic carbon did not differ between the management systems. The root surface and volume were increased in TC1 and TC2, with higher productivity and sugar yield than under NTC. The sugarcane variables did not differ between the managements. The soil physical quality in the plant row was preserved under management TC1 and TC2, with an improved root development and increases of 18.72 and 20.29 % in productivity and sugar yield, respectively.

Sooty blotch and flyspeck control with fungicide applications based on calendar, local IPM, and warning system

The objective of this work was to compare fungicide application timing for the control of sooty blotch and flyspeck (SBFS) of 'Fuji' apples in Rio Grande do Sul state, Brazil. The following treatments were evaluated in two growing seasons: two warning system-based (modified version of the Brown-Sutton-Hartmann system) spray of captan plus thiophanate methyl, with or without summer pruning; two calendar/rain-based spray of captan or a mixture of captan plus thiophanate methyl; fungicide spray timing based on a local integrated pest management (IPM) for the control of summer diseases; and a check without spraying. Sooty blotch and flyspeck incidence over time and their severity at harvest were evaluated. The highest number of spray was required by calendar/rain-based treatments (eight and seven sprays in the sequential years). The warning system recommended five and three sprays, in the sequential years, which led to the highest SBFS control efficacy expressed by the reduced initial inoculum and disease progress rate. Summer pruning enhanced SBFS control efficacy, especially by suppressing SBFS signs which tended to be restrained to the peduncle region of the fruit. Sooty blotch and flyspeck can be managed both with calendar and the grower-based IPM practices in Brazil, but a reduced number of sprays is required when the warning system is used.

Quantitative control of Lettuce mosaic virus fitness and host defence inhibition by P1-HCPro

Two Lettuce mosaic virus isolates capable of overcoming the resistance afforded by the resistance gene mo1² in lettuce, LMV-AF199 from Brazil, and LMV-E, an European isolate, were evaluated for the rapidity and severity of symptoms induced on the lettuce variety Salinas 88 (mo1²). The mosaic symptoms on Salinas 88 plants inoculated with LMV-AF199 appeared 7 days post-inoculation (dpi) and 15 dpi for LMV-E. The symptoms induced by LMV-AF199 in this cultivar were also more severe than those induced by LMV-E. In order to identify the region of the viral genome responsible for this phenotype, recombinant viruses were constructed between these isolates and the phenotype of each recombinant was analysed. The region encoding proteins P1 and HcPro from LMV-AF199 was associated with the increased virulence in Salinas 88.

Management of crotalaria and pigeon pea for control of yam nematode diseases

Management of plant-parasitic nematodes with the use of nematicides has not been recommended for small farmers that grow yam in the Northeastern region of Brazil, due to its high cost and residue toxicity. The use of plants with antagonistic effect to nematodes and green manure which improves soil chemical, physical and biological characteristics can be a viable and low cost alternative to control parasitic nematodes. This work aimed to evaluate the effect of crotalaria (Crotalaria juncea) and pigeon pea (Cajanus cajan) plants on the control of yam nematodes. Three experiments were carried out. The first was conducted under in vitro conditions to evaluate the nematostatic and nematicide effect of extracts from fresh and dry matter of the above ground parts of crotalaria, pigeon pea, and the combination of both. The second experiment was carried out under greenhouse conditions to evaluate the effect of soil amendment with crotalaria, pigeon pea, and the combination of both in the infectivity of Scutellonema bradys, using tomato plants as the host plant. The third experiment was conducted under field conditions to evaluate the effect of crotalaria, pigeon pea, and the combination of both, cultivated between yam planting rows and incorporated to soil surface, on yam nematodes. The aqueous extract obtained form fresh matter of crotalaria had a nematicide effect of 100% for S. bradys. Extracts from dry matter of both crotalaria and pigeon pea did not have any nematicide effect, but had a nematostatic effect. Incorporation of crotalaria to soil inhibited infectivity of S. bradys in tomato seedlings. These results showed that planting crotalaria alone or in combination with pigeon pea, between the yam planting rows, is an efficient method for controlling S. bradys and Rotylenchulus reniformis associated with yams. Crotalaria can be used for controlling these plant-parasitic nematodes in soil.

Monitoring of mechanical sugarcane harvesting through control charts

ABSTRACT Statistical process control in mechanized farming is a new way to assess operation quality. In this sense, we aimed to compare three statistical process control tools applied to losses in sugarcane mechanical harvesting to determine the best control chart template for this quality indicator. Losses were daily monitored in farms located within Triângulo Mineiro region, in Minas Gerais state, Brazil. They were carried over a period of 70 days in the 2014 harvest. At the end of the evaluation period, 194 samples were collected in total for each type of loss. The control charts used were individual values chart, moving average and exponentially weighted moving average. The quality indicators assessed during sugarcane harvest were the following loss types: full grinding wheel, stumps, fixed piece, whole cane, chips, loose piece and total losses. The control chart of individual values is the best option for monitoring losses in sugarcane mechanical harvesting, as it is of easier result interpretation, in comparison to the others.

Genetic characterization of Brazilian bovine viral diarrhea virus isolates by partial nucleotide sequencing of the 5'-UTR region

Nineteen isolates of bovine viral diarrhea virus (BVDV) from Brazil were genetically characterized through partial nucleotide sequencing and analysis of the 5'UTR region. The isolates were grouped as BVDV-1 (11/19), BVDV-2 (6/19) or "atypical" pestivirus (2/19). Among the BVDV-1, eight isolates were classified as subgenotype BVDV-1a, whereas most (4 out of 6) BVDV-2 belonged to subgenotype 2b. Two isolates from aborted fetuses were not classified into any genetic group, being considered atypical BVDVs. Genetic diversity among Brazilian BVDV isolates may be responsible for vaccination and diag-nostic failure and therefore may influence the control strategies for BVDV infection in the country.

Survey on control and management practices of equine helminthes infection

Twenty-nine stud farms were selected in the Medium Paraíba region of the Rio de Janeiro state, Brazil. After an interview with the person responsible for the animals, faecal samples were collected from mares and analyzed via the EPG technique, faecal cultures, Sedimentation-centrifugo-flotation, and modified Ueno and Baermann techniques. The prevalence of helminths in the mares and in the stud farms was calculated. The stocking rates of pasture, change of horse bedding, absence of pasture rotation, absence of technology in the property, and less frequent treatment of the animals were associated with a greater prevalence of helminths, showing that these variables must be considered in equine control programs. The intensity of the parasitism was also associated with the stocking rate of pasture, absence of dunghill, presence of the animals only in paddocks, lack of technology in the property, less frequent treatment of the animals, and absence of the use of rotation regarding the anthelmintic class.

Foot rot and other foot diseases of goat and sheep in the semiarid region of northeastern Brazil

This paper reports the occurrence and epidemiology of outbreaks of foot rot and other foot diseases in goats and sheep in the semiarid region of Paraíba, northeastern Brazil. Four farms were inspected for the presence of foot lesion in sheep and goats and for environmental conditions, general hygiene, pastures, and disease control measures. The prevalence of foot lesions was 19.41% (170/876) in sheep and 17.99% (52/289) in goats, ranging between 5.77% and 33.85% in different farms. Foot rot was the most common disease, affecting 12.1% of the animals examined (141/1165), but with significantly higher (p<0.05) prevalence in sheep (13.69%) than in goats (7.27%). The frequency of malignant foot rot was also significantly lower (p<0.05) in goats (9.53%) than in the sheep (40.83%). On one farm, Dorper sheep showed significantly higher (p<0.05) prevalence of foot rot (17.5%) than Santa Inês sheep (6.79%), and the number of digits affected was also higher in the former. Dichelobacter nodosus and Fusobacterium necrophorum were isolated from cases of foot rot. White line disease was found in 3.95% of the animals, sole ulcers in 1.29%, foot abscess in 1.03% and hoof overgrowth in 0.5%. The high rainfall at the time of occurrence, grazing in wetlands, clay soils with poor drainage, presence of numerous stony grounds, closure of the flocks in pens at night, and introduction of affected animals were considered predisposing factors for the occurrence of foot diseases.

Prevalence and risk factors for Leptospira spp. in cattle herds in the south central region of Paraná state

The aim of this study was to determine the prevalence of anti-Leptospira spp. antibodies and the risk factors for Leptospira spp. infection in breeding cattle herds in the south central region of Paraná state. It was based on the statistic delineation/serological samples and information regarding the selected farms employed in the study of bovine brucellosis for Paraná state in the context of National Program for Control and Eradication of Brucellosis and Tuberculosis. A total of 1.880 females aged >24 months from 274 non vaccinated herds were studied. Serum samples were tested for antibodies against Leptospira spp. using microscopic agglutination test (MAT) with 22 Leptospira serovars. The epidemiological questionnaire was applied on all the selected farms and aimed to obtain epidemiological data. Hundred eighty one of 274 herds were positive for Leptospira spp./presenting prevalence of positive herds of 66.06% (IC95%=60.12-71,65%). Presence of >43 cattle (OR=3.120; IC=1.418-6.867)/animal purchase (OR=2.010; IC=1.154-3.500)/rent of pastures (OR=2.925; IC=1.060-8.068) and presence of maternity paddock (OR=1.981; IC=1,068-3,676) were identified as risk factors for leptospirosis due to any serovar in the multivariate logistic regression. Risk factors for leptospirosis due to serovar Hardjo were presence of >43 cattle (OR=3.622; IC=1.512-8,677)/animal purchase (OR=3.143; IC=1.557-6.342)/rent of pastures (OR=4.070; IC=1.370-12.087) and presence of horses (OR=2.981; IC=1.321-6.726). These results indicate that Leptospira spp. infection is widespread in the south central region of Paraná state and that factors related to the herd characteristic and management are associated with the infection.

Assessing bovine babesiosis in Rhipicephalus (Boophilus) microplus ticks and 3 to 9-month-old cattle in the middle Magdalena region, Colombia

Babesia sp. is a protozoan hemoparasite that affects livestock worldwide. The Colombian Middle Magdalena is an enzootic region for babesiosis, but there is no previous research providing detail on its transmission cycle. This study aims to assess some Babesia sp. infection indicators in cattle and ticks from the area, by using direct microscopic and molecular techniques to detect the infection. In the cattle, 59.9% and 3.4 % positivity values for B. bigemina and mixed infection (B. bovis + B. bigemina) were found respectively. In ticks, the positivity of B. bigemina reached 79.2% and 9.4% for the mixed infection. The degree of infestation in the region was 3.2 ticks per bovine. There was positive correlation between tick control acaricide frequencies and infestation in bovines. This leads us to infer that control periodicity greater than 90 days, in stable zones, is an abiotic factor that benefits the acquisition of protective immunity in calves, the natural control of the infection and eventual disease absence. It is necessary to monitor the disease by applying new entomological and parasitological indicators showing the complexity of this phenomenon.

Testing pigs of non-technified rearing farms for serum antibodies against Taenia solium in a region of the state of São Paulo, Brazil

Abstract: Taenia solium is a zoonotic tapeworm of great importance in developing countries, due to the occurrence of human taeniasis and cysticercosis. Pigs have an important role in the biological cycle of the parasite as intermediate hosts. The scientific literature has been describing risk factors associated with the occurrence of this disease that must be avoided in countries with poor sanitation, in order to reduce the exposure of swine to the parasite eggs. This research focused on testing pigs of non-technified rearing farms for serum antibodies against Taenia solium in the region of Jaboticabal municipality, in the state of São Paulo, Brazil. The found prevalence was 6.82% (CI 95% 4.18 - 9.45) at animal level and 28.87% (CI 95% 16.74 - 40.40) at herd level. These figures are probably associated with low technification adoption during animal rearing in the studied area, which increased the exposure of the animals to risk factors associated with the occurrence of Taenia solium complex. The results found based on serological evidences of swine cysticercosis in the studied region serves as a warning to public sanitary authorities to improve public health and control T. solium.

Corn cultivar intercropping with arboreal legumes for weed control

Gliricidia (Gliricidia sepium) seedlings are usually beneficial to corn crops when planted between corn rows. The objective of this work was to assess the effects of corn intercropped with gliricidia and "sabiá" (Mimosa caesalpiniifolia), a species native to the Brazilian northeastern region, on weed control and corn green ear and grain yields. The experiment was carried out at Estação Experimental da Universidade Federal Rural do Semi-Árido - UFERSA (Mossoró, State of Rio Grande do Norte, Brazil). The experimental design consisted of randomized complete blocks (multifactorial design) with five replications, arranged in split-plots. The plots consisted of corn cultivars AG1051 and BM 2022; subplot treatments (six) were no-hoeing, twice-hoeing (at 20 and 40 days after sowing) and intercropping with gliricidia and "sabiá", either directly sown or transplanted, simultaneously with corn sowing. The intercropped leguminous plants were spaced 0.40 m from each other, and directly seeded or transplanted (30-day-old seedlings) in between two 1 m-spaced corn rows. Twenty three weed species were identified during the experiment. Gliricidia seedlings were superior to "sabiá" seedlings with regard to plant height and survival rate. The highest corn green ear and grain yields were found for twice-hoed subplots, while the lowest yield was found for no-hoed or intercropped subplots. However, grain yield values in intercropped treatments did not differ from grain yield values in hoed plots. In addition, marketable husked green ear mean weights did not differ between twice-hoed subplots and subplots directly seeded with gliricidia and "sabiá". Such results indicated that corn benefited from the intercropping system, but intercropping with gliricidia and "sabiá" transplanted resulted in lower benefits than with the direct sowing of those species.

Weed Phytosociological and Floristic Survey in Agricultural Areas of Southwestern Goiás Region

The use of the Roundup Ready(r) technology and the cultivation of a second crop influence the floristic composition of weed communities in Brazilian Central-West region cropping systems. This study has aimed to diagnose the dominant weed species in southwestern Goiás in areas of genetically-modified and conventional soybeans, using phytosociological and floristic surveys. Weed sampling was obtained by collecting all the plants present within a 0.5 m hollow frame, randomly thrown 20 times in each of thirty-five agricultural areas in the 2012/2013 harvest. Field survey was carried out in three periods: before desiccation for soybean sowing, before postemergence herbicide in soybean first application and before postemergence herbicide application in late harvest. A total of 525 m2 was inventoried and 3,219 weeds were collected, which included 79 species, 58 genera and 28 families. Families Poaceae, Asteraceae, Euphorbiaceae, Fabaceae, Amaranthaceae, were the most representative in the survey. Species Cenchrus echinatus, Glycine max, Chamaesyce hirta, Commelina benghalensis, and Alternanthera tenella stood out in importance. The RR+millet soybean treatment had the highest number of species (44), while the conventional soybean + sorghum treatment had the lowest number of species (18). The highest number of species was recorded in first sampling period. Treatments conventional soybean + maize and conventional soybean + millet showed higher similarity (70%), while treatments RR soybean + millet and conventional soybean + sorghum showed the least (51%). Species of difficult control were recorded in all cultivation systems analyzed.

Comparative study of human exposure to mercury in riverside communities in the Amazon region

Four populations in the Amazon area were selected for a comparative study of mercury-exposed and non-exposed populations: São Luiz do Tapajós, Barreiras, Panacauera, and Pindobal Grande. The highest mercury levels in human hair samples were found in São Luiz do Tapajós and Barreiras, greatly exceeding the limits established by the World Health Organization. Panacauera showed an intermediate level below 9 µg/g. This was the first comparative and simultaneous evaluation of mercury exposure in the Amazon area. Also, thanks to this type of monitoring, we were able to eliminate the uncertainties about the reference dose. On the basis of these data, we can conclude that the mercury levels detected in exposed populations of the Tapajós River basin may be dangerous not only because they are above the World Health Organization limits, but also because the simultaneous mercury detection in non-exposed populations with similar characteristics provided a valid control and revealed lower mercury levels. Our results support the importance of continuous monitoring in both exposed and non-exposed populations.

Etiology of diarrheal infections in children of Porto Velho (Rondonia, Western Amazon region, Brazil)

In the present study, 470 children less than 72 months of age and presenting acute diarrhea were examined to identify associated enteropathogenic agents. Viruses were the pathogens most frequently found in stools of infants with diarrhea, including 111 cases of rotavirus (23.6% of the total diarrhea cases) and 30 cases of adenovirus (6.3%). The second group was diarrheogenic Escherichia coli (86 cases, 18.2%), followed by Salmonella sp (44 cases, 9.3%) and Shigella sp (24 cases, 5.1%). Using the PCR technique to differentiate the pathogenic categories of E. coli, it was possible to identify 29 cases (6.1%) of enteropathogenic E. coli (EPEC). Of these, 10 (2.1%) were typical EPEC and 19 (4.0%) atypical EPEC. In addition, there were 26 cases (5.5%) of enteroaggregative E. coli, 21 cases (4.4%) of enterotoxigenic E. coli, 7 cases (1.4%) of enteroinvasive E. coli (EIEC), and 3 cases (0.6%) of enterohemorrhagic E. coli. When comparing the frequencies of diarrheogenic E. coli, EPEC was the only category for which significant differences were found between diarrhea and control groups. A low frequency of EIEC was found, thus EIEC cannot be considered to be a potential etiology agent of diarrhea. Simultaneous infections with two pathogens were found in 39 diarrhea cases but not in controls, suggesting associations among potential enteropathogens in the etiology of diarrhea. The frequent association of diarrheogenic E. coli strains was significantly higher than the probability of their random association, suggesting the presence of facilitating factor(s).