Centro Agrícola

5-12

Authors: Dienelys Hernández Pérez 1 , Manuel Díaz Castellanos , Reinaldo Quiñones Ramos , Ramón Santos Bermúdez , Nayanci Portal González , Lidcay Herrera Isla

The “in vitro” growth inhibition of M. phaseolina by four rhizobacteria as well as disease management on field with the use of biological media and natural products were evaluated. Although none of the tested bacterial strains achieved completely inhibit the growth of the pathogen “in vitro” through both bioassays employed, the control of disease under controlled conditions was more efficient with the use of B. cepacia and P. fluorescens. During field assessments, M. phaseolina was the most prevalent fungal pathogen in bean crops, however, all tested treatments significantly reduced the impact of the disease. Despite the fact that moisture conditions prevailing during the crop assessments did not encourage the development of M. phaseolina, the effectiveness of the treatments for full protection of bean plants toward this soilborne fungus. Field assessments in two different locations and weather conditions show that treatment of bean seeds with biological media (B. subtilis and P. fluorescens) allows crop protection against disease caused by M. phaseolina.

23-27

Authors: Yosel Pérez Pérez, José Ramón Pérez Milán, María de la Luz La O Echevarría, Roberto González Hernández y Yenima Pellón Guzmán

The effects produced by the Xanthomonas albilineans (Ashby) Dowson on stalks with acute symptoms of the disease have been addressed by different authors, however, is unknown the effects that may occur in seropositive asymptomatic stems to the bacteria. This work has as objective to study the impact of the presence of bacteria in the colonized tissues, as well as the relationship between the concentration of cells and the expression of symptoms. In 900 stems of 14 cultivars detected the bacteria by serology and identified the variables Brix of stem with handheld refractometer, as well as the contents of fructose, glucose and sucrose whit High Performance Liquid Chromatographic. The presence of the bacterium X. albilineans in asymptomatic stems affects the sugar content of the same, which constitutes a contribution to the knowledge of the pathogen - host relations for this disease. The stems are colonized by the bacteria, but the amount of UFC/g of tissue or per ml/juice does not mean that a cultivar is more or less susceptible. In stalks with symptoms the cell density increases toward the foliage, while that in the asymptomatic happens to the contrary.

34-40

Authors: Luis Gustavo González Gómez, María Caridad Jiménez Arteaga, Leandro Vaquero Cruz, Irisneisy Paz Martínez, Alejandro Falcón Rodríguez, Luis Araujo Aguilera

In evaluating the effect of the chitosan on the growth of postures of tobacco an experiment was developed in an area located in the CCSF “Luis Ramírez López”, state of Granma, in the campaign 2013-2014, using the seeds of the variety Corojo 2006. The investigation was developed in stonemasons to open field, applying chitosan to a dose from 350 mg ha-1 to the 15, 20 and 25 days after the germination and a treatment control. A design was continued totally randomized with four treatments, and three repetitions by treatment, they were evaluated the variables: longitude of the leaves (cm), the width of the leaves (cm), height of the plants (cm), number of leaves (OR), the width of the shaft (cm), dry and fresh mass of the leaves and the root (g). Finally, it was carried out the economic valuation. The obtained data were evaluated through an analysis of variance of simple classification and a test of stocking comparison by Tukey. The obtained results allowed to reach the conclusion of the beneficial effect of the chitosan on the indicators of quality of the postures, benefiting the producing with 51 025.50 CUP ha-1 when the bioestimulant applies to the 25 days after germinating the seeds.

49-55

Authors: Orlando Barrueta Leyva, Carmen Verónica Martín Vasallo, Leónides Castellanos González , Roquelina Jiménez Carbonell

The work was developed in the municipality of Abreus, Cienfuegos province between January and February 2013. The objective was to determine the effectiveness of the watery extract of Euphorbia lactea Haw for the control of Plutella xylostella L. in the cabbage crop (Brassica oleracea L.). Bioprepared was obtained fractioning pieces among 3 to 5 cm of young shafts of E. lactea in mature plants of 2 - 3 m of height. 3 kg of the vegetable fractions was deposited in 10 L of water, (proportion 0,3 kg L-1), remaining the mixture in rest during 24 hours. It was removed twice a day in favor of the pointers of the clock. The pH was evaluated at the beginning, and at 24 hours to the bioprepared and to the different concentrations of the watery extract. Concentrations were compared at 12,5 %, 25 %, 50 %, with a control or witness without treatment, as much in laboratory as in field, against larvae of P. xylostella. The watery extracts of E. lactea obtained the highest larvacide effect in the first 24 hours, being the L1 larval stadiums more susceptible. The watery extract E. lactea in proportions of 0,3 kg L-1 to the concentrations of the 25 % and 50 % achieves technical effectiveness against P. xylostella under laboratory and field conditions, without manifesting toxicity to the cabbage crop.

63-70

Authors: Joaquín Montalván Delgado, José Rodríguez Zayas, Isabel Alfonso Terry, Eida Rodríguez Lema, Osmany Aday Díaz, Isabel Torres Varela, Yoslén Fernández Gálvez y Nicolas Quintana Bernabe

To develop a system that increase the precision in the resistance evaluations to sugarcane brown rust disease through the use of the quantitative sampling, six cultivars of differential behavior versus the disease (PR980, My5514, Ja60-5, C334-64, C323-68 and B4362) were studied. A random block experimental design with three replications was used in a heavy infections conditions obtained from the cultivar highly susceptible B4362. The evaluations were done at three and five months of age, in the three-thirds: bottom, half and top of the +1, +3 and +5 sugarcane plant leaves of 10 plants for replica. The variable total leaf area affected of the leaf and in each third was analyzed. In 2 cm2 were observed the long and wide of the biggest and more frequent pustule, the total of pustule and the area of the biggest and more frequent pustule, and the area percentage occupied by the most frequent pustule by each cm2 were determined. Variance analysis and Tukey tests as well as confidence intervals analysis to determine the coefficient to use as constant of the pustule width, due to the little variation of this parameter were realized. The +3 leaf represented the half infection of the incidence of the brown rust, constituting for it the most appropriate to carry out the observations and the half third. An equation was also obtained to calculate the area occupied by pustules with a high level of confidence.

80-89

Authors: Enildo Osmani Abreu Cruz, Gerardo González Oramas , Ramón Liriano González, Juan Israel Veliz Alonso, Peter Ost y Zuleica Monzón Cepero

The use of the ecological fertilizer foliar HerbaGreen in the cultivation of potato, Ajiba variety, combined with different levels of chemical fertilization (NPK) was evaluated. The research was carried out at UBPC “La Rosita”, corresponding to the “Vladimir Ilich Lenin” Crop Company, in the municipality of Jovellanos, Matanzas province. Four fertilization treatments were established (25, 50, 75 and 100 % of the NPK dose) plus the application of the HerbaGreen product at a dose of 1 kg ha-1 in 200 L of water, in addition to the control (100 % NPK Without the ecological fertilizer). Three applications were made during the biological cycle of the crop. From the leaves, stems and roots, was determined the concentration of starch, carbohydrates and total soluble protein and starch concentrations in tuber yield and its components. The use of the HerbaGreen allowed reducing the amounts of chemical fertilizer in the potato crop. The treatment of 100 % of NPK plus the HerbaGreen product showed significantly higher yields than the other treatments.