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Bonfante-Cabarcas R.,University Centroccidental Lisandro Alvarado | Rodriguez-Bonfante C.,University Centroccidental Lisandro Alvarado | Vielma B.O.,University Centroccidental Lisandro Alvarado | Vielma B.O.,Instituto Nacional Of Investigaciones Agricolas | And 4 more authors.
Cadernos de Saude Publica | Year: 2011

This study investigated risk factors associated with positive serological status for Trypanosoma cruzi antibodies in 26 rural communities including 905 households, 2,156 humans, and 333 dogs in Lara State, Venezuela. Serology was performed with ELISA and MABA. Data were obtained from entomological, demographic, and clinical surveys. Risk factors were determined through binary logistic regression. Seroprevalence was 7.24% in humans and 6.9% in canines. Positive serological status was positively associated with the Rhodnius prolixus vector, age, maternal history of Chagas disease, tobacco chewing, presence of mammals and birds in the household, household disarray, mud-and-wattle outbuildings, and animal nests and burrows in the peridomicile, and negatively associated with tobacco and alcohol consumption, history of cancer, and storage deposits in the peridomile. In conclusion, Chagas disease in this rural area is an old phenomenon transmitted by R. prolixus or by the transplacental route, associated with socio-cultural habits related to poverty, sylvatic surroundings, and the host's medical history.

With the aim of identifying the social and economical characteristics of producers that integrate the socialist red of productive innovation (SRPI) of ovine and goat, a descriptive research was done with a transactional design in the field, at Goajira parish, Zulia state, Venezuela, which is a limited area by its arid weather to semi arid and high temperatures. The population considered for this research was formed by 215 producers of ovine and goat of the Wayuu ethnic that form the SRPI. 140 producers were selected at random, out of which were applied a structured survey that asked about social and economic variables. The obtained results show that a high percentage of producers are women that combine the production of ovine and goat along to craftwork (59%), also, producers live in production units, have a low educative level and an elevate illiterate rate. A high percentage does not have legal documentation of the property of their lands (60%), that is why it is so difficult to have access to financing processes to improve their production systems and elevate their improvements and reduce the elevate number of extreme poverty (90%).

Ojeda A.,Central University of Venezuela | Canelones C.,Central University of Venezuela | Munoz D.,Central University of Venezuela | Gil J.L.,Instituto Nacional Of Investigaciones Agricolas
Tropical and Subtropical Agroecosystems | Year: 2013

To determine the chemical composition and nutritive value of selected browse species by buffaloes (Bubalus bubalis L.) in a silvopastoral system at a semi-deciduous tropical forest (SDTF), epidermal fragments in fecal samples from 14 males of Murrah breed were evaluated. The animals grazed for 91 days in 85 ha located in Portuguesa State, Venezuela, of which 35 ha corresponded to natural grass pastures (969.3 ± 28.6 kg DM ha-1), and the rest to SDTF with 463 plant ha-1. Eleven botanical families and 22 species were identified, 40.9% belonged to the Fabaceae family. The specie Guazuma ulmifolia (Sterculiaceae) had the highest relative dominancy (60.4%) and an Importance Value Index of 162.6. 60.4% of epidermal fragments corresponded to herbaceous Poaceae, and the rest was distributed among five different species, with the highest occurrence (94.6%) for Samanea saman and Sida acuta. There were differences (P<0.05) among selected species in the proximal composition (40.9 ± 7.1% dry matter, 16.0 ± 4.1% crude protein and 2.9 ± 1.2% ether extract), neutral detergent fiber (41.6 ± 2.2%), acid detergent fiber (25.9 ± 3.8%), minerals (1.6 ± 0.59% Ca and 0.1 ± 0.02% P), condensed tannins (0.9 ± 0.7%), potential gas production (67.8 ± 37.3 ml g-1 DM), and in vitro organic matter digestibility (54.2 ± 8.0%). In general, the edible fraction of selected browse species evaluated here was similar to other tropical browse forages and confirms the strategic value of this biomass in buffalo nutrition at silvopastoral system. Furthermore, these browse species could be employed in agroforestry systems to achieve a better integration of livestock production in tropical areas.

Rosales-Robles E.,Instituto Nacional Of Investigaciones Agricolas | Sanchez-de la Cruz R.,Instituto Nacional Of Investigaciones Agricolas | Cerda-Garcia P.A.,Antonio Narro Agrarian Autonomous University
Revista Fitotecnia Mexicana | Year: 2012

Ineffective weed control is an important problem in grain sorghum (Sorghum bicolor L. Moench) production in northern Tamaulipas, México. Several options for chemical weed control in sorghum in pre-(PRE) and post - emergence (POST) were evaluated under field conditions in 2007 and 2008. Atrazine and amicarbazone 750 g ha -1 applied PRE resulted in good control of wild sunflower (Helianthus annuus L.) and Palmer amaranth (Amaranthus palmeri S. Wats), without causing damage to sorghum plants. Among herbicides applied POST to six-leaves sorghum, prosulfuron 17 g ha -1 showed excellent control of wild sunflower in both years, however Palmer amaranth control was only regular in 2008 and it did not control silverleaf nightshade (Solanum elaeagnifolium Cav.) in any year. The mixture of carfentrazone 2.5 g ha -1 + 2, 4-D 225 g ha -1 and 2, 4-D to 720 g ha -1 showed regular weed control, but damage was caused in sorghum reducing grain yield. Dicamba at 144 g ha -1 resulted in a similar weed control to 2, 4-D but with less damages to sorghum and without reducing its yield. Bromoxinil 480 g ha -1 effectively controlled wild sunflower and Palmer amaranth but had no effect on silverleaf nightshade. Bentazon at 960 g ha -1 controlled wild sunflower, but it was ineffective on Palmer amaranth and on silverleaf nightshade. Results indicate that there are several options for the control of wild sunflower and Palmer amaranth, while silverleaf nightshade must be controlled by adding a POST hormonal herbicide such as 2, 4-D or dicamba.

Tagliafico A.,Instituto Nacional Of Investigaciones Agricolas | Tagliafico A.,University of the East Venezuela | Rago N.,Instituto Nacional Of Investigaciones Agricolas | Rago N.,University of the East Venezuela | And 2 more authors.
Fishery Bulletin | Year: 2012

We studied a small artis-anal fishery for the spotted eagle ray (Aetobatus narinari) off Margarita Island in northeastern Venezuela. We analyzed data from 413 fishing trips directed at A. narinari over a 29-month sampling period (August 2005-December 2007). These trips yielded 55.9 metric tons and 1352 individuals from which a subsample of 846 females and 321 males was used for biological data. Maximum fishing effort and landings occurred between February and May, and catch per unit of effort was highest between December and February and between July and October with an overall average of 3 individuals and 133 kg per trip. The overall sex ratio was significantly different from 1:1 with a predominance of females. Females ranged in size with disc widths (DW) from 64 to 226 cm. Males ranged in size between 97 and 190 cm DW. There was no statistically significant difference between male and female length-weight relationships. Mean fecundity was estimated at 3.09 embryos per female, and the largest embryo measured 44.5 cm DW. Females in different maturity stages were found in all months, except November 2007, the month when all females were immature. Postgravid females occurred mainly during the periods of January-May and July-October. Mean length (L50) at maturity was estimated at 129.2 cm DW for males and 134.9 cm DW for females. This study provides much needed information on the biology and life history of A. narinari for the management of an intensive, directed, small-scale fishery for this little known species in northeastern Venezuela.

Rice cultivars are affected directly and indirectly by the insect sogata. The mechanical damage or direct loss, is produced after feeding and ovoposition on the young leaves tissues, while the indirect damage is produced after the transmission of the Rice hoja blanca virus. We studied the morpho-anatomic structures associated with the resistance of the mechanical damage produced by the insect, in six rice cultivars, including controls for resistance and susceptibility (Makalioka and Bluebonnet 50), during August 2011, in Fundacion Danac, Venezuela. Samples were taken from leaf 3, where cuticle thickness, presence of macrohair, microhair and silica bodies in the second third of the leaf was evaluated. A significant difference to thickness of the cuticle, the presence of microhair in the leaves, and presence of silica bodies was observed among cultivars, determining a significant correlation among the number of macrohair and microhair in the adaxial leaf blade with the presence of silica bodies, and thickness of the cuticle and number of posed insects. Thickness of the cuticle and presence of silica bodies in the intercostals space of microhair and macrohair showed to be the variables most related to mechanical damage and resistance mechanism.

Uzcategui J.,University of Los Andes, Venezuela | Araujo Y.,Instituto Nacional Of Investigaciones Agricolas | Mendoza L.,University of Los Andes, Venezuela
Bioagro | Year: 2011

The horticultural farms in Pueblo Llano, Mérida State, have been using uncontrolled quantities of different kinds of pesticides, so the aim of this work was to determine the residual levels of organochlorine pesticides (OCPs) in those soils. Samples were taken in 20 farms, and Soxhlet extraction procedure (EPA 3540C) and sulfur elimination (EPA 3660B) were performed. According to the EPA 8081A method, the OCPs were determinined by gas chromatography with electronic capture detector. Nine OCPs were quantified in most samples in the following concentration ranges (mg·kg -1): DDT (0,04-0,99); DDE (0,01-0,56); DDD (0,04- 0,83); α-endosulfan (0,01-0,47); β-endosulfan (0,02-0,45); endosulfan sulfato (0,04-0,62); aldrin (0,005-0,009); dieldrin (0,01- 0,03), and endrin (0,01-0,04). The soils presented high levels of organic matter, which may favor OCPs retention. It was found that the total OCPs concentration, DDT and isomers (DDE and DDD) decrease as the soil pH increases, and enlarge as the clay percentage increases. The soils were classified as potentially contaminated, according to their levels of DDT, dieldrin and endrin.

Munoz-Falcon J.E.,Instituto Nacional Of Investigaciones Agricolas | Vilanova S.,Polytechnic University of Valencia | Plazas M.,Polytechnic University of Valencia | Prohens J.,Polytechnic University of Valencia
Scientia Horticulturae | Year: 2011

Listada de Gandía is one of the most renowned Spanish eggplant (Solanum melongena L.) landraces. Assessing its genetic diversity and relationships, as well as devising tools for its identification, is of great relevance for the enhancement and protection of this landrace. Forty-two eggplant accessions, which included 25 Striped accessions, of which 19 were of the Listada type (six accessions of Listada de Gandía, eight of Other Spanish Listada, and five of Non-Spanish Listada) and six of the Other Non-Spanish Striped group, and 17 Non-Striped accessions were characterized with 17 genomic SSRs and 32 EST-SSRs. Genomic SSRs had, as a mean, a greater polymorphism and polymorphic information content (PIC) than EST-SSRs. Although Listada de Gandía proved to be genetically diverse, specific and universal alleles for two SSR markers were found for this landrace. All the Listada accessions cluster together in the multivariate PCoA and UPGMA phenograms performed, and are separated from the Other Non-Spanish Striped and Non-Striped accessions. Also, Listada de Gandía accessions were clearly differentiated from the Other Spanish Listada and Non-Spanish Listada accessions in these analyses. SSR markers revealed of great utility to obtain a specific fingerprint for the Listada de Gandía eggplant as well as to establish the uniqueness and distinctness of this landrace. This information will be very helpful for the enhancement and protection from imitation of Listada de Gandía, and contributes to support its potential recognition with a Protected Designation of Origin (PDO) status. © 2011 Elsevier B.V.

Liendo R.J.,Instituto Nacional Of Investigaciones Agricolas
Revista de la Facultad de Agronomia | Year: 2015

The turning effect every 24, 48 and 72 was studied in a region of Venezuela Miranda state, hours for the same period of six consecutive fermentation days in the cocoa flavor profile. A trained panel evaluated the sensory attributes “Cacao”, “Acidity”, “Bitter”, “Astringent”, “Fruity”, “Floral”, “Nuts”, “Candy/Malta/Sweet”, “Raw/Green” and “Other”. The variance estimator REML, Procrustes Analysis and subsequent Principal Component Analysis were used for data analysis. Although the fermentation period was the same for all trials and only varied the number of volts that influenced the flavors “Cocoa”, “Acidity”, “Astringency”, “Nuts”, “Candy/ Malta/Sweet” so highly significant (P≤0.001). The flavors “Fruity” and “Others” showed varying levels of significance (P≤0.05 -0.01). It was observed that the average intensities were high on the turning every 72 hours in the flavors “Acidity”, “Bitter”, “Nuts” and every 24 hours for the “Fruity”. The attributes that together form the sensory harmonic profile affectivities producing nice constituted a distinctive group (“Cocoa”, “Fruity”, “Candy/Malta/Sweet” and “Nuts”). The flavor “Raw/Green” taste Raw/Green was very little intense and its variation was not significant statistically. It is considered an indicator of poor cocoa fermentation the cocoa. The attribute with the most power discriminate was the “Acidity” followed by “Fruity”. © 2015, Universidad del Zulia. All Rights Reserved.

The supply of plant nutrients in optimal amounts is a primary goal of fertilization programs. The objective of this research was to determine uptake levels of the macroelements N, P, K, Ca and Mg by tomato plant during its life cycle under glasshouse conditions. The research was carried out at Quibor experimental field of the INIA, Lara State, Venezuela. The tomato variety Alba was selected and planted at 30 cm between plants in the row and 80 cm between rows. A completely randomized design with four replications was used. Each plot consisted of 6 rows of 10 meters long each. Fertirrigation was supplied daily. Samples of plants were taken at 20, 40, 60, 75 and 125 days after transplanting (dat). It was found that in the early stages of the plant growth, the stem and leaves are the organs that accumulate more dry matter, and at the final stages the leaves and fruits have the greatest contributions. The leaf was the organ which showed the highest accumulation of calcium, while the fruit showed the highest potassium accumulation. Nitrogen was the third nutrient which presented a moderate level of extraction. The greater extraction of N, P and K corresponded to the fruit, while Ca and Mg were stored primarily by the leaves. The total removal of macronutrients for the tomato plants was 970, 358, 147, 2603 and 405 mg per plant for N, P, K, Ca, and Mg, respectively.

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