Centro Agrícola

11-16

Authors: Dagoberto Guillén Sánchez, Celeste Isamar Cadenas Vásquez, Irán Alia Tejacal, Víctor López Martínez, María Andrade Rodríguez y Porfirio Juárez López

The aim of the research was to evaluate the in vitro sensitivity of Colletotrichum acutatum antracnosis to seven fungicides. It began with an isolate preserved in the ceparium of the Phytopathology Laboratory of the High School Studies of Xalostoc, Morelos. A completely randomized design was used to evaluate the fungicides benomyl, diphenoconazole, azoxystrobin, trifloxystrobin, copper oxychloride, fluoxastrobin and captan, at high, medium and low doses, for a total of 22 treatments with six repetitions. Sterile distilled water was applied to the control. The treatments were applied at a rate of 5 mL per plate, which contained PDA medium and a mycelial disc (Ø 5 mm). The inoculated plates were incubated at 24 °C, in 12 hour photoperiod. The colony diameter was measured every 24 hours and the percent inhibition was calculated. A bifactorial variance analysis was performed, according to Fungicide and Dose; and the differences between treatments were detected by the LSD test with 95 % confidence. The diameter of the colony and the percentage of inhibition did not show differences for dose levels, without significant effects for the interaction of both factors, fungicides, and dose. However, all doses of the different fungicides inhibited colony growth compared to the control. The benomyl, difenoconazol and captan fungicides were able to totally reduce the growth of the C. acutatum colony; followed by copper oxychloride, azoxystrobin, fluoxastrobin and trifloxystrobin in decreasing order. Only benomyl, difenoconazol, captan and copper oxychloride achieved more than 50 % inhibition.

23-29

Authors: Ramón Liriano González, Manuel Alexander Terán Reyes, Dania Bárbara Núñez Sosa, Dianela Ibáñez Madan y Jovana Perez Ramos

The present work was developed with the aimed to evaluate the application of worm's humus in the production of seedlings of tomatoes (Lycopersicon esculentum Mill) cultivar Roma, in the rural settlement San Isidro-San Ignacio, municipality of Tinaquillo, State of Cojedes, Republic of Venezuela. Five treatments were studied: chemical fertilization (control), worm`s humus at 4 t ha-1 bottom, worm`s humus at 4 t ha-1 bottom + worm`s humus leaching above foliage at 15 days of seeds germination, worm`s humus at 6 t ha-1 bottom and worm`s humus at 6 t ha-1 bottom + worm`s humus leaching (1L per 50 L water) above foliage at 15 days of seeds germination. The experimental design was a random block with three replications. After 25 days seed germination it was measured the plant height, number of leaves per plant, stem diameter, root length, fresh and dry mass of leaf and root. The higher values obtained in each one of the studied parameters during tomatoes plant growing were achieved with the application of 4 t ha-1 worm`s humus at bottom plus worm`s humus leaching (1L por 50 L water) above foliage at 15 days after seed germination.

43-48

Authors: Isilda Braz Impene Combo, Roberto Valdés Herrera, Edilberto Pozo Velázquez, Marlen Cárdenas Morales

The present work was carried out at the Laboratory of Insect Pathology of the Center for Agricultural Research (CIAP), located at the Universidad Central "Marta Abreu" de Las Villas, with the aim to evaluate the effect of the ozone (O3) treatment on the seed vigor of P. vulgaris. To determine the effect of the ozone on the seed vigor, a germination test, electrical conductivity test and emergency tray test were performed on two common bean varieties (BAT-304 and Delicias-364). Ozone did not affect the vigor of the seeds of the varieties BAT-304 and Delicias-364. The exposure time of P. vulgaris seeds to 150 ppm of O3 did not affect the parameters of germination speed and the percentage of germination of the seeds.

58-64

Authors: Elio Lescay Batista, Yadira Vázquez Ramírez y Fernando Celeiro Rodríguez

During the months of November to February of the periods 2009-2010 and 2010-2011, two experiments in the Granma province, Cuba, were carried out in order to evaluate the variability and relations between the variables morphoagronomycs evaluated. Nineteen genotypes of black bean in parcels of 7 m2 in a design of blocks at random with three replications were seeded. The planting distances were 0.70 m between furrows and 0.05 m between plants. Sixteen variables were evaluated and the data were processed by means of descriptive statistic and simple correlations. The results showed strong positive correlations between the pairs of variables: yield-weight of seeds for plant (r = 0.99) and number of seeds for plant - number of pod for plant (r= 0.94). The variables number of leaves for plant, height of the plant, number of pots for plant, number of seeds for plant, weight of seeds for plant, longitude of the seed and grain yield presented high variability, which can be useful for being used in programs of improvement in this species.

75-81

Authors: Diego Augusto Fatecha Fois, Maria do Carmo Lana, Jessica Caroline Coppo, Cesar Kent Hoshiba, Bruna Broti Rissato, Osmar David Cañete Escobar, Erix Rubén Fernandez Gonzalez, Marcos Daniel Espínola Vallejos

Nitrogen fertilization is essential to raise sugarcane yield in soils deficient in N. The objective of this study was to evaluate the effect of nitrogen application in production and borer attack on sugarcane. The experiment was conducted at Escobar District, State of Paraguarí, Paraguay. Three sugarcane growing seasons were evaluated during 2011-2013. The experimental design was randomized blocks with seven treatments and three repetitions, with annual application of increasing of nitrogen (0, 30, 60, 90, 120, 150 and 180 kg ha-1). At 360 days of each crop cycle, harvest was performed with the following assessments: industrial plant height, number of internodes per plant, infestation intensity index and yield. The nitrogen rate of maximum technical efficiency and maximum economic efficiency was determined. Statistical analysis of variance, means comparison and regression were performed. Nitrogen fertilization did not affect plant height and number of internodes, but increased yield and borer attack. For every kg ha-1 of nitrogen applied 0.25 t ha-1 of yield is added, and 0.27 % of infestation intensity index increase is obtained. The rate of maximum technical efficiency was 157,4 kg N ha-1 for a yield of 73,6 t ha-1, and the rate of maximum economic efficiency was 136.5 kg N ha-1 for a yield of 88,2 t ha-1.

88-94

Authors: Juan José Reyes Pérez, Ricardo Augusto Luna Murillo, Mariana del Rocío Reyes Bermeo, Darwin Zambrano Burgos y Vicente Francisco Vázquez Morán

The use of organic fertilizers in the fertilization of crops is an alternative to the problems generated by the intensive use of chemical fertilizers. The objective of this research was to evaluate the application to soil of organics fertilizers compared with a control treatment with chemical fertilization on the yield and its components in pepper (Capsicum annuum L.). Treatments consisted in to apply worm humus, water hyacinth compost, a mixture with 50 % worm humus and 50 % of water hyacinth compost, and a chemical control. It was evaluated fruits quantity per harvest, fruit length, diameter and fruit weight per harvest and yield. Results showed that the plants that were supplemented with worm humus, followed by worm humus + water hyacinth they had significantly better response with respect to the length, diameter and weight of the fruits.