Centro Agrícola

5-13

Authors: Germán Andrés Aguilera-Arango ,Álvaro Caicedo-Arana,Darwin Fabian Lombo-Ortiz ,Dubert Yamil Cañar-Serna, Mónica Betancourt-Vásquez

Context. Pomegranate (Punica granatum L.) is considered a promising fruit for its nutritional value and medicinal attributes. In Colombia, interest is recently perceived in this species, so there is a growing demand in obtaining planting material. However, there are no adequate propagation schemes, which limits the planting potential in this country. Objective. To evaluate the effect of the diameter of the pomegranate basal cuttings sown in different environments on the percentage of survival to establish a preliminary vegetative propagation methodology for this specie under nursery conditions. Methods. 405 pomegranate cuttings cv. Mina Shirin were collected, classified in three categories according to their diameter in thin, medium and thick, which were evaluated in three different environments (100 % sun exposure, 50 % sun exposure and humid chamber with 10 % sun exposure) for a total of nine treatments, each with three repetitions of 15 cuttings. Results. Significant differences were found regarding the type of cutting, because those who presented diameters greater than 1.2 cm showed greater potential for vegetative propagation of pomegranate. Regarding the environments evaluated, there were also significant differences, the best of which was the humid chamber, where a survival rate of 40.74 % was found. Conclusions. The establishment of an efficient pomegranate vegetative propagation methodology with quality attributes is projected soon, using basal cuttings with diameters greater than 1.2 cm.

23-32

Authors: Diana González-AguiarAriany Colás-SánchezOralia Rodríguez-LópezDelia Luisa Álvarez-VázquezSirley Gattorno-MuñozAhmed Chacón-Iznaga

The investigation was developed in the agricultural company “Valley del Yabú” located in Santa Clara, Villa Clara province. The objective was to estimate the soil organic matter content with the use of visible and near infrared (vis-NIR) reflectance spectroscopy technique in Cambisol soil. Soil samples were collected at the landscape level to conform the calibration set and in two specific fields to constitute the validation sets. A portable spectrophotometer was used in the wavelength range from 399 to 1697 nm. Reflectance data were related to soil organic matter using partial least squares regression (PLSR). The model accuracy was determined by means of the determination coefficient (R2). Results showed that the reflectance lectures varied with the wavelength and there was an increment from the visible region (379 - 780 nm), to the near infrared region (780 - 1700 nm). The vis-NIR calibration model accuracy obtained at the landscape level was evaluated of good and very good with R2 values of 0.89 and 0.90 respectively when it was validated in the selected specific fields, which showed the correct estimation of the soil organic matter content.

43-50

Authors: Pável Oriol Rodríguez Vázquez ,Fernando Franco Flores

Vascular plants Type specimens, housed since the first half of the twentieth century at Cienfuegos Botanical Garden Herbarium “Atkins”, in Cuba, formerly directed by the Arnold Arboretum of the Harvard University, are listed. The Historic Section of this collection has more than eighty botanists, authors of several publications, and contains duplicates in important international herbaria. The present research has the objective of detect their samples on which specie’s names were based. Types designated in the labels were confirmed consulting other herbaria and literature. Furthermore, botanist represented in our collection, were search in other herbaria. Results was 51 Types specimens, belong to 31 species, 19 genera and 15 botanical families; widespread in 15 herbaria with 118 duplicates. Was added, references of publication, distribution, and Endangered Category. Coccothrinax (Arecaceae) species are outstanding, while main collectors were Brother León, J. G. Jack, R. A. Howard and J.P. Carabia. This report raises the possibility of taxonomic studies of the Cuban Flora collections. The AJBC collection may contain other unidentified samples with taxonomic value, so it is important to continue its analysis.

59-65

Authors: Mariol Morejón Garcia ,Sergio Carrodeguas Díaz ,Félix Ponce Ceballos ,Francisco Gonzales Breijo ,Yoerlandy Santana Baños ,Danny Velázquez Ceballos ,Yosbel López Quintana

The research was conducted at the "El Jaguey" belonging to the Cooperative Credit and Service "Ramón López Peña" of the Council Popular Cortés, Sandino, Pinar de Río, with the aim of determining vegetative and yield development in five cultivars of onion (Allium cepa L.). The established cultivars were ‘Caribe 71’, ‘Diandra F1’, ‘Regent F1’, ‘Red Creole’ and ‘Texas Early Grain E 502’, which were distributed in a completely randomized block design with three replications. The planting was carried out in rows, at a distance of 0.30 x 0.10 m, with homogeneous seedlings of each cultivar. Evaluations were carried out at 32 and 60 days after transplantation, where the variables plant height, number of active leaves, diameter of the false stem and total fresh mass were characterized. At harvest time, the fresh mass, the equatorial and polar diameters and the humidity were determined in the bulbs. The crop yield was also estimated. The results showed greater vegetative development in the cultivars 'Texas Early Grano E 502' and 'Red Creole', although the former reached yields above 35 t ha-1 and significantly exceeded the other cultivars. The equatorial diameter of the bulb determined its fresh mass in more than 85%, with the exception of the cultivar 'Texas Early Grano E 502', while the percentage of humidity of the bulb exceeded 75% in all cases and was influenced by the color of the same.

75-79

Authors: Ariany Colás Sánchez ,Ahmed Chacón Iznaga, Pedro Cairo Cairo

The study was carried out to evaluate the structure and quality of two soil subtypes Eutric Cambisols and Vertic Eutric Cambisols, in the Villa Clara province, in areas of anthropic influence. Through the morphological characterization of the profiles and the land cover, that included the evaluation of physical and chemical indicators. The results obtained revealed, notable differences in the morphology of the profiles, which are not significantly associated with the different management systems, but they are attributed to the characteristics of each subtype.

5-15

Authors: Sofía Peñaherrera Villafuerte, Galo Cedeño García, Fernando Solórzano Alcívar, George Cedeño-García, Pedro Terrero Yépez

The main objective of the research was to evaluate the efficacy of mixtures of Trichoderma spp. and palm oil in the management of cocoa moniliasis. The experiment was carried out during 2016 in a 40-year-old polyclonal plantation, made up of clones EET-19, EET-95 and EET-103, sensitive to moniliasis. The treatments evaluated were: palm oil + Trichoderma koningiopsis and T. stromaticum (T1), palm oil + T. ovalisporum (T2), T. koningiopsis + T. stromaticum (T3), T. ovalisporum (T4), Hydroxide of Copper (T5) and a control treatment (T6). The main variables recorded were: the area under the disease progress curve (ABCPE), the control efficacy, the yield and the net economic benefit. The data were subjected to the analysis of variance and the comparison of means through the Tukey test, with a 5 % probability of error. The treatments significantly influenced the evaluated variables. T1 and T2 showed the highest moniliasis control efficacy with 50.27 and 41.68 % respectively, in addition to having lower disease intensities over time (ABCPE) compared to control. Likewise, these treatments showed a greater increase in the yield of dry grains with 30.18 and 29.46 %, in their respective order; at the same time, they achieved the highest net economic benefits with 1094 and 1050 USD ha-1. The mixtures of Trichoderma spp. and palm oil were effective in managing the disease and increase the yield and economic benefit of cocoa.

22-30

Authors: Osmany de la Caridad Aday Díaz, Héctor García Pérez

The orange rust of the sugar cane (Puccinia kuehnii (W. Krüger) E. J. Butler) is a disease of potential danger for the sugar industry in Cuba. The objective of the research was to determine the spatial distribution of orange rust in leaves infected by P. kuehnii, type of distribution of the pustules and the possible use of a quantitative variable that allows estimating the affected leaf area with a superior precision to observation of the human eye. From the cultivar C01-227 (susceptible to the disease), 25 leaves were collected and the +5 leaf was selected. The type of spatial distribution of the pustules was determined by calculating the variance / mean ratio and the Morisita index. A maximum of 6.88 pustules per cm2 was determined in leaves with 25 % of affected leaf area and an average of 2.26 in leaves with affectation from 5 to 25 %. The pustules for square centimeters was significantly higher in the middle and apical thirds; but in the third of the leaf, their value average or their maximum is not related directly with area affected in the leaf.

41-53

Authors: Alonso David Ojeda-Falcón, Olgioly Domínguez-Quintero

An agroecological Voisin’s Rational Grazing production system was established in 2013 in Barinas, Venezuela, with the aim of studying a sustainable agroecological route in acid-sandy soils. A pasture of 27 ha with Urochloa brizantha and Urochloa ruziziensis was divided in 64 paddocks. Four treatments were established: application of a single dose of 1.5 Mg ha-1 asphaltic emulsion; single dose of 440 kg ha-1 of phosphoric rock; asphaltic emulsion with phosphoric rock, with the same previous dose, and control, only with Voisin’s Rational Grazing. Four replicates of each treatment were established in 16 randomly chosen paddocks in which periodic soil and vegetation samplings were carried out. The highest yields of dried matter in t ha-1 yr-1 of pasture corresponded to asphaltic emulsion (34-62) and asphaltic emulsion with phosphoric rock (54-48) in comparison to the control (22-31) and phosphoric rock (24-25) treatments, for years 2015 and 2016, respectively. This brought about better quality pastures, from the first year of the management the pasture yields tripled and an increase of the animal load from 1.2 to 3.7 LU ha-1 between 2015 and 2016, and to 4.3 LU ha-1 in 2017 was achieved. Applying a single dose of asphaltic emulsion aided to accelerate the regular increases with time. The labile fractions of P showed that Voisin’s Rational Grazing induced a high phosphoric fertility which displaced phosphorous as the main limiting factor in primary productivity of these soils of low natural fertility, that are widely distributed in savannah ecosystems and the Neotropic.

66-74

Authors: Isbel Rodríguez Seijo, Pedro Martínez Campos, Ubaldo Álvarez Hernández, Arahis Cruz Limonte, Elier Mora Pérez

The objective of this work was to evaluate the effect of planting distances of 1.60 m and furrow with a wide base (0.40 m x 1.40 m) on the growth and agricultural yield of sugarcane. The experimental design used was random blocks with four replications and two treatments equivalent to the plantation frameworks most used in this crop in Cuba; the cultivar used was C90-469. At 30 days after planting (ddp) the number of shoots per linear meter was evaluated; at field closure, 120 ddp, the length, width and number of active leaves and the leaf area per plant were evaluated; at 360 ddp, length, diameter and number of internodes, length of stems, number of stems per linear meter, weight of stems, number of stems per hectare, and agricultural yield were evaluated. In the framework of a wide-base furrow plantation, there was an increase in the number of shoots per linear meter; the leaf area, mean internodes, length and diameter of the same, length of the stems and weight of the stems was less than the planting distance of 1.60 m; however, the number of stems per hectare at the time of harvest was higher, reaching 97 290 and an increase in agricultural yield of 11.8 % in relation to the distance 1.60 m.

84-88

Authors: Rosabel Rodríguez Rojas, Vladimir Nuñez Caraballo, Sinaí Barcia Sardiñas, Roberto Valdés Herrera

Obtained a methodology it permits carry out a diagnosis and effective characterization of the agricultural urban production of the blessed cities white of egg and Cienfuegos, by keeping in mind by having the location of the organoponics, cercaniases to fixed sources of emission of polluting agents and ways of access, cultivations that it develops, areas that occupy, as well as the environment built. For it carried out the update and mapping of active organoponics in the cities object of study.

5-12

Authors: Germán Andrés Aguilera Arango, Janneth Cecilia Ortiz Cabrera

Valle del Cauca is perceived as one of the most important departments in Colombia, which bases its economy on agriculture. Among the effects that occur in the production units, the presence of giant African snail (Lissachatina fulica) has been detected, which has become a problem in the region, due to its voracity towards a wide variety of crops, including fruits and vegetables. The objective of the present study was to determine the current geographical distribution of L. fulica in productive farms of Valle del Cauca. For this, plant species of economic importance for the department were monitored as hosts and food source. Between February 2016 and July 2019, 1899 properties were visited, located in 41 of the 42 municipalities of Valle del Cauca. In each crop, transects in “zigzag” forms were traversed, in which 30 plants were sampled randomly in order to observe the presence of L. fulica. African snail was found in 14 productive systems such as avocado, chili, citrus, pomegranate, soursop, guava, lettuce, mango, passion fruit, papaya, plantain, pineapple, tomato and grape, located in 61 farms distributed in 11 municipalities of the department, among that stand out La Unión and Toro. Also, there was a dispersion grouped into three concentration cores, located geographically in the north, center and south of the department. In this way, the study generates base information on the current geographical distribution of L. fulica in Valle del Cauca.

22-27

Authors: María Caridad Jiménez Arteaga, Luis Gustavo González Gómez, Ana Julia Verdecia Corría, Anabel Oliva Lahera

The work was carried out in the "Cerca Blanca" seed farm with the objective of comparing the effect of three biostimulants on bean cultivation, sown in two periods, when applied to the seeds, before sowing. The treated seeds were sown under a completely randomized design at a distance of 0.70 m between rows and 0.07 m between plants. The following variables were evaluated: number of legumes per plants, number of seeds per legume, mass of one thousand seeds (g) and agricultural yield (t ha-1). The best results corresponded to the treatment where Azofert F® was applied for the two planting periods, with an agricultural yield of 2.57 and 0.869 t ha-1, followed by treatment with QuitoMax® (2.11 and 0.774 t ha-1). The control treatment was the one with the lowest yield for both periods (1.27 and 0.46 t ha-1). Azofert F® is the bioproduct that most affects performance during both periods.

38-44

Authors: Maydolis Agüero Cabrera, Roberto Valdés Herrera, Edilberto Pozo Velázquez

The need to eliminate chemical products and the search for ecological alternatives for the control of pests in stored grains based on vegetable powders, motivated the determination of the effect of milled powders of Piper auritum Kunth on Sitophilus oryzae L. for this P. auritum was prepared in different variants and drying temperatures, in two phenological phases: vegetative and reproduction-flowering, dried in the sun and shade, in three temperatures (35, 45 and 60 ° C). Six insects were placed in four replicates for each treatment, the deaths caused in the treatments were recorded and compared. In the vegetative phenological state, dried in the sun, the best efficiencies of P. auritum powder were obtained when the material was dried at 45 and 60 ° C, with 38 and 45 % mortality respectively, while in the shade, the dried material at 35 ° C he achieved 100 % mortality, this being the best treatment of all. The leaves of this plant (dried in the shade and milled) can be used for the control of S. oryzae in stored grains.

50-54

Authors: Mónica Tamayo Isaac, Dalgis Gerrero Barriel, Osmany Aday Díaz, René Barbosa García, Pablo Pablos Reyes

Determining which fungal genera grew on orange rust uredospores of the B80250 variety was the objective of this work, carried out in the Phytopathology laboratory of the South East Sugar Cane Research Station. The confirmation and certification of the isolates was carried out by the Plant Health Mycology Laboratory of Santiago de Cuba. ImageJ Software was used to measure microorganisms and their structures. Orange rust uredospores showed internal dark colorations and complete colonization by fungal growths. For the first time, fungal genera were isolated in uredospores from Puccinia kuehnii (Krüger) Butler in Cuba.

61-68,

Authors: Dailín Rodríguez Tassé, René Nivardo Barbosa García, Adrián García Perú, Alexeis Urquiza Ricardo

The experimental work was carried out during the wet period of the Integral Weed Control Campaign, in plantations of the cold season (June - December) of 2018, in the Sugarcane Growers Farm “Vitalio Acuña”, belonging to the Sugar Mill Dos Ríos, Santiago de Cuba. The objective was to assess the effectiveness of two planting methods for weed management in sugarcane. The experiment was laid out in split plot design using three replications, each plot contained 14 furrows of 100 m long, on a cambisol soil. In each planting methods the weeds coverage at 30, 60, 90 and 120 days after the application of herbicide were determined and field closure was evaluated. The Environmental Impact Coefficient and the pollutant load to the atmosphere were determined. Field closure in dual furrow system occurred 60 days before the traditional one, thus limiting the presence of weeds. There were significant differences between the two planting systems. Traditional plantation required four more tasks for weed control. The performance of more control tasks increased the environmental impact coefficient and the expulsion of polluting gases into the atmosphere. The most effective planting method for weed control in sugarcane was dual furrow system, which at the same time reduces pollution to the environment.

5-12

Authors: Daniel Perales-Rosas, Ricardo Hernández-Pérez, Dagoberto Guillén Sánchez, Víctor López Martínez, Irán AliaTejacal, Porrio Juárez López

The effect of the Poncho®, Cruiser® 5 FS and Tools® TS insecticides applied in sorghum seed treatment (Sorghum bicolor L. Moench) on the germination, incidence and severity of M. sacchari/sorghi and agronomic variables was evaluated. The hybrid genotype sorghum used was Ambar 752E443K (Asgrow®). The treatments consisted in the application of Poncho® at doses 4, 5, 6 and 8 mL kg-1 of seed; Cruiser® 5 FS at a dose of 2.5, 3.5, 5 and 7 mL kg-1 of seed; Tools® TS at doses 5, 6, 7 and 9 g kg-1 of seeds and an absolute control treatment. No negative effects of the treatments were observed on the germination, with germination exceeding 96 % in all treatments. Doses of insecticides not exhibit a controlling effect on the populations of M. sacchari/sorghi. The effect of the insecticide treatments was not positive in the agronomic variables plant height, fresh leaf weight, fresh stem prisoner, fresh panicle weight, fresh grain weight, chlorophyll content and Brix degrees.

21-29

Authors: Juan José Reyes Pérez, Emmanuel Alexander Enríquez Acosta, Miguel Ángel Ramírez Arrebato, Aida Tania Rodríguez Pedroso, Marisol Rivero Herrada

With the objective of evaluating the influence of Chitosan on seedlings of tomato cultivars, an experiment was developed in shaded mesh house conditions, with control of temperature, relative humidity. Eight treatments were used which resulted from the combination of Pomodoro and Floradade tomato cultivars with three doses of Chitosan 1, 2 and 3 g L-1 and a control without application. The treatments were distributed in a completely randomized design with three repetitions. 21 days after germination, evaluations were made to variables related to the growth and development of the crop. The data were subjected to a multivariate analysis of principal components with Biplot representation and a double variance analysis and multiple means comparison were subsequently performed. When applying the principal component analysis two new variables were formed (C1, C2) that managed to explain 91.24 % of the total variance of the experiment. C1 presented the highest contribution with 85.66 %, which was characterized by the fresh and dry mass of the stem, the fresh and dry mass of the leaves, the fresh mass of the root, the diameter and length of the stem, as well as the concentration of N, P and K, in the foliar part of the plant. The analysis of variance showed that the doses that caused a greater positive effect on the cultivars in most of the variables evaluated were 1 and 2 g L-1.

44-52

Authors: Segundo Ramiro Mora Quilismal, Edith Aguila Alcantara, Vinicio Revelo Ruales, Hernán Benavides Rosales, Luis Balarezo Urresta

The present investigation assessed the effect of two biofertilizers Fosfotic and Safer micorrizas, alone or in combination, as complement to reductions in phosphorus chemical fertilizer, in the potato production in Andisols from Carchi. A field experiment with randomized block design (four replicates and 10 treatments) was carried out at the San Francisco Experimental Center of the Carchi State Polytechnic University between November 2017 and May 2018. The treatments used were selected from a previous experiment conducted in this same entity the previous year. The number and weight of tubers per plant, total and caliber production and total yield were evaluated, root dry weight and foliage phosphorus content were determined at 120 days; In addition, nutrient recovery efficiency was calculated. An economic analysis of the evaluated treatments was also performed. The combination of better productive results, greater efficiency in phosphorus absorption and good economic results was that of the treatment where the phosphorus fertilizer was reduced by 75 %, combined with both biofertilizers, followed by the treatment where the chemical fertilizer was reduced to 25 % and combined with safer mycorrhizae. The double reciprocal regression evidenced the influence of phosphorus on the production and quality of tubers. These treatments had a cost benefit ratio above 0.90, higher than the treatment with chemical fertilization.

61-64

Authors: Eulalia Gómez Santiesteban, Yusmila Guevara Verdecia, Ana N. San Juan Rodríguez, Teresita Lemes Rodríguez, Marlyn Pérez Rodríguez, Yusnel Cutiño

The use of plant growth promoting diazotrophic bacteria has occupied an important place in agricultural microbiology, Azospirillum being among the most promising. The objective of this study was to determine the effect of NITROFIX® on the radical development of three varieties of sugarcane. Evaluations were made in plastic pots with a capacity of 2 Kg, placed on wooden supports to the environment with three varieties of cane, through an experimental design of randomized blocks with three replicas and three treatments: (C, T1, T2). The inoculation of Azospirillum sp., it provoked a stimulating response on the radical growth, which is why NITROFIX® is considered as a promising alternative of biofertilization in sugarcane plants.

65-68

Authors: Daina Rodríguez Miranda, Horacio Grillo Ravelo

The presence of insects is very common in poultry facilities. Some of these insects can transmit diseases so it is very important to know which species inhabit them. In this way, effective control measures can be used to help reduce the presence of insects. Information on this subject is scarce, therefore the objective was to determine the main taxonomic groups of insects present in the quail droppings, in a poultry farm in the central area of the province of Villa Clara. The results highlight the presence of the housefly, species of the order Diptera is a plague of relevance in poultry production.

5-15

Authors: Juan José Reyes-Pérez, Diana Rosa Aponte-Rodríguez, Dany Maikel Sariol-Sànchez, Emmanuel Alexander Enríquez-Acosta, César Ramiro Bermeo Toledo, Luis Tarquino Llerena Ramos

In the present work the repellent and molluscicidal activity was evaluated in laboratory conditions of the aqueous extracts of stinky sweet potato (Agdestis clematidea Moc. & Sessé ex DC) on the snail (Subulina octona Bruguière), in conditions of laboratory and of field, in an organic lettuce crop (Lactuca sativa L.) var. Black Seeded Simpson. The treatments consisted in the application of the extract at three concentrations 50, 75 and 100 % at a dose of 20 ml m-2 and a control with calcium oxide. The experimental random block design was used: evaluating the technical effectiveness of the repellent action and molluscicide of the extracts, number of individuals per square meter and damaged leaves of lettuce. The repellent and molluscicide action of the extract was demonstrated in laboratory conditions, achieving the best results when the extract was applied at a concentration of 100 %. In addition, the population of S. octona was reduced and the increase in damage to the leaves of the crop was limited, evidencing the possibility of using aqueous extract in the control of the pest.

22-29

Authors: Amalia Domínguez Suárez, Rodolfo Darias Rodríguez, Yordanys Martínez Dávalos, Elianis Alfonso Negrín

The selection of tolerant varieties of bean to the drought can constitute a strategy that permit minimizing the effect of the hydric deficit on the yield and the quality of the bean grain. The objective of work was to identify more tolerant varieties to the drought, at the farmstead Sabanilla of her CCS "Sabino Pupo", Unión de Reyes. The morphologic characteristic and common bean indicators of yield of eight varieties (CC 25-9 R, BAT 58, Güira 89, CC 25-9 white, CC 25-9 black, Tomeguín, Velazco Largo and BAT 304) were evaluated, in different conditions: four irrigations (drought) and ten irrigations (optimal conditions of humidity). With the results of reproductive index (IR), sensibility index to drought (ISS) and the percentage of losses of the yield (PR) allowed bring to a following conclusion: the varieties more tolerant behavior in the conditions of experimentation where: Tomeguín, BAT 304 and CC 25-9 R and the more susceptible: Velazco Largo and y CC 25-9 black.

39-48

Authors: Juan José Reyes-Pérez, Marco Pérez-Santo, Dany Maikel Sariol-Sánchez, Emmanuel Alexander Enríquez-Acosta, César Ramiro Bermeo Toledo, Luis Tarquino Llerena Ramos

The present Investigative work was carried out with the objective of evaluating the effect of different doses of bovine dung on indicators of development and the performance of rice. A randomized block design with six treatments was used: control (without fertilization), 20, 30, 40, 50 and 60 t ha-1 of cow manure and four replications. The height of the plants, agricultural yield, full grains for plants, full grains and vain for panicles were evaluated. The results showed significant increases in the yield of rice compared to the control with values that ranged between 0.30 and 2.2 t ha-1, standing out the treatment with 60 t ha-1 as the most effective. The application of this organic fertilizer allows to increase the rice production in a friendly way for the health of man and the environment.

58-66

Authors: Pedro Martínez Campos, Olga Lidia Haramboure Camacho, Víctor Daniel Gil Díaz, Manuel Emilio Montes de Oca Fuentes, Isbel Rodríguez Seijo

Research was carried out in the period from December 2017 to March 2018 in the "San José" farm, belonging to the Credit and Services Cooperative "El Vaquerito" of Santa Clara municipality, with the objective of recognizing the existing weeds in the common bean crop and its influence on agricultural yield in intermediate sowing season. The sowing of the cultivar "Milagro Villareño" took place on December 9, 2017, on a moderately washed soft Brown soil, in a randomized block design with three treatments and three replications. To determine the composition of the population of weeds, five samples were taken by the diagonal method. The indices of relative abundance and similarity of the weeds were determined. The harvest was made at 87 days after sowing, at which time 10 plants were randomly chosen by plot for a total of 30 for treatment, to which were evaluated: effective legumes per plant, effective seeds per legume and effective seeds per plant; as well as the mass of 100 effective seeds per treatments. Agricultural yields were also estimated in each treatment. The population of weeds was represented by 15 species, of which Echinochloa colona (L.) Link. and Portulaca oleraceae L. reached the highest values of relative abundance. The highest agricultural yield was obtained when weed control was applied up to 60 days after the sowing.

76-85

Authors: Marta Barrera Fontanet, Gerardo Javier Cervera Duverger, Leonides Peña Rivera, Agustín Cobas Elías, Midiala Peña Prades, Odalis Barquié Pérez

In order to evaluate the percentage of weed cover in different cultivation techniques, a study was made of the population of weeds, in the production unit "Manuel Sánchez" of the Sugar Company "Argeo Martinez", Guantánamo, between April and July 2014, in the 1st shoot strain, variety C90-647, on a soil alluvial, compacted, from 24 days after the mechanized harvest. The percentage of coverage, wealth, dominance and species diversity were evaluated in five management techniques and three replications, as well as the economic valuation. The results showed that the coverage percentage varied indistinctly by treatment and remained below 1.4 % from 30 days until the study stage was concluded. The Margalef index was higher for the Deep Cultivation treatment 1.10 + 1.60 m, while the similarity index for all the combinations at 90 days after assembly showed imbalance of species between treatments with values lower than 0.5. The diversity of weeds showed that a total of 11 weed species inhabited the area with a predominance of the Poaceae; relative abundance was observed in five species with superiority of Cynodon dactylon revealing a gradual decrease in the Deep Cultivation treatment 1.10 + 1.60 m during the period. The lowest and highest cost for clean days, was for the treatments Unaltered coverage of crop residues and deep cultivation 1.10 + 1.60 m respectively.

96-98

Authors: Melisa María Hernández Pérez, Manuel Díaz Castellanos

The work was carried out in the "San Ramón" farm of Santa Clara municipality, Villa Clara province, with the objective of determining the energy efficiency of the common bean cultivar Buenaventura. For this purpose, the energy equivalents of the inputs and outputs of the system were used. The sources of direct energy (fossil fuels) and indirect energy (fertilizers, pesticides and seeds) were taken into account. The results showed that this cultivar was very efficient energetically with a value of 1.57. The largest amount of energy consumed in the system was determined by chemical synthesis inputs (fertilizers and pesticides).