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Publications (3)0 Total impact

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    ABSTRACT: In the 70’s and 80’, peanut or groundnut crop constituted one of the main oil crops in the Oriental Region of Venezuela,unfortunately the presence of the fungi Cercospora arachidicola and Cercosporidium personatum, causal agents of theearly and late leaf spot, respectively, caused a sharp decreasing of the nut yields, consequently the use of differentfungicides to control of these foliar diseases were applied, in only one crop season up to ten fungicides application wereused, increasing the production costs up to non financial limits, in the other hand, these fungicide applications caused aenvironment deterioration for the heavy quantity of the toxic product applied. For these reasons, the peanut cultivarevaluation is necessary to select tolerant or resistant genotypes to the foliar spots caused by these fungi and this is the mainobjective of the present work, and evaluate agronomically 25 genotypes of this crop. The experiment was carried out at theEstación experimental de Sabana de la Universidad de Oriente in Jusepin, Monagas state, Venezuela. During the seasoncrop (109 days) a rain of 258.4 mm was registered, the minimum temperature was 22.7 ºC and the maximum temperaturewas 30.4 ºC and the mean temperature was 26.3 º. A 5 x 5 triple lattice design was used with three replications. TheDuncan’s Multiple Range Test was used to detect differences among genotypes (p ≤ 0.05). Twenty two confectionery were sowed. The disease tolerance was evaluated according to Giandiana’s scale. Significant differences were found forfruit and nut yield/ha, numbers of fruit in 100 grams, 100-fruit weight, numbers of fruits and seeds/plant, numbers ofseeds/fruit and numbers of seed in 100 fruits and there were not significant differences for 100-seed weight, oil content andempty fruit percentage. The biggest nut yield/ha was for Indian cultivar 84448, being similar to the yields of other thirteengenotypes but superior to the other eleven genotypes. All genotypes had a value of four in the Giandiana’s scale, id est,there were classified as susceptible (more than three lesions which can reach the petiole, but not the stem) to leaf spot in theevaluations carried out at 82 and 89 days after sowing. These results indicated nut yield differences among genotypes inspite of there was not differences in the susceptibility to the disease, this suggested that the more yielder cultivars weretolerant to leaf spot, so that, exist the possibility of get tolerant genetic materials trough a breeding program of peanut cropwith the cultivars evaluated in this assay.
    Revista Científica UDO Agrícola. 01/2003;
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    ABSTRACT: The use of induced mutations in the genetic improvement of plants has allowed the obtaining of cultivars of high adaptationin many species. However, their use should be preceded of experiments that allow to determine the appropriate dosimetry,as well as to familiarize to the plant breeder with the effect that radiations have on the used vegetable material. With thisobjective, it was carried out a experiment at glasshouse of Postgraduate of the Nucleo de Monagas of the Universidad deOriente, using seeds of two cowpea cultivars (TC 9-6 and A-4), which were irradiated with five dose of gamma rays (20;40; 60; 80 and 100 Krad), compared with a control without irradiation. The seeds were irradiated in the reactor of 60Co ofthe Instituto Venezolano de Investigaciones Científicas (IVIC) in Caracas and sowed 5 days after the irradiation, usingaluminium trays of 45 cm of high, 30 cm of wide and 15 cm of depth. Washed sand was used as substrate. A 2 x 5 factorialexperiment in a randomized complete block design was used with four replications. The Duncan’s multiple range test wasused to detect the differences among treatment. The level of 5 % of signification was used. The evaluated parameters were:plant survival, mean number of days to the total germination, plant height and number of leaves at 7 and 21 days after thesowing, aerial part dry weight and radicle dry weight. Significant interaction was observed between the genotypes andirradiation doses in all characters, excepting mean number of days for complete germination and for radicle dry weight,where differences were only observed for simple effect of the studied factors. When analyzing the data and to compare themwith the treatments of seeds without irradiation, it was observed that in all the evaluated characters, the 50 lethal dosis(LD50) or 50 reductive (GR50) were between 20 and 60 Krad. In the other hand, there were varietal differences to theradiation, being cultivar TC-9-6 more resistant than A-4.
    Revista Científica UDO Agrícola. 01/2002;
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    ABSTRACT: La utilización de mutaciones inducidas en el mejoramiento genético de las plantas ha permitido la obtención de cultivares de alta adaptación en muchas especies. Sin embargo, su utilización debe estar precedida de ensayos que permitan determinar la dosimetría adecuada, así como familiarizar al mejorador sobre el efecto que las radiaciones tienen sobre el material vegetal utilizado. Con este objetivo se realizó un ensayo en el Invernadero de Post-grado del Núcleo de Monagas de la Universidad de Oriente, utilizando semillas de dos cultivares de frijol (TC 9-6 y A-4), las cuales fueron irradiadas con cinco dosis de rayos gamma (20; 40; 60; 80 y 100 Krad), comparadas con un testigo sin irradiar. Las semillas fueron irradiadas en el reactor de 60Co del Instituto Venezolano de Investigaciones Científicas (IVIC) en la ciudad de Caracas y sembradas 5 días después de la irradiación, utilizando bandejas de metal de 45 cm de alto, 30 cm de ancho y 15 cm de profundidad. Se utilizó arena lavada como sustrato. El ensayo fue sembrado bajo un diseño de bloques al azar en arreglo factorial con 4 repeticiones. Las diferencias entre los promedios se obtuvieron con la Prueba de Ámbitos Múltiples de Duncan al 5% de probabilidad. Los parÁmetros evaluados fueron: Sobrevivencia de las plÁntulas, número medio de días para la germinación, altura de las plÁntulas y número de hojas a los 7 y 21 días después de la siembra, peso seco de la parte aérea y peso seco de la raíz. Se observó efecto de la interacción entre los genotipos y las dosis de irradiación en todos los parÁmetros, a excepción del número medio de días para germinación completa y para el peso seco de la raíz, donde se observaron diferencias solo para el efecto simple de los factores estudiados. Al analizar los datos y compararlos con los tratamientos de las semillas sin irradiar se observó que en todos los parÁmetros evaluados la dosis letal media (LD50) o dosis reductiva media (GR50) se encuentra entre 20 y 60 Krad. Así mismo se pudo observar diferencias entre los cultivares a la radiación, siendo el cultivar TC-9-6 mÁs resistente que el cultivar A-4.
    Revista Científica UDO Agrícola, ISSN 1317-9152, Vol. 2, Nº. 1, 2002, pags. 22-28. 01/2002;