Centro Agrícola

14-24

Authors: Silvio de Jesús Martínez Medina, Maikel Rodríguez Egido, Lesly Díaz Suarez, Edilio Quintero Fernández, Victor Daniel Gil Díaz, Gudelia Rodríguez Valdés

In common beans (Phaseolus vulgaris L.), complex interactions occur between the genotype and climatic, edaphic and biotic factors, for which it is necessary to study the response of the different cultivars. The objective of the study was to characterize the physiological response of four commercial cultivars in slightly leeched brownish greys soils and its intermediate sowing season. The experiments were carried out at the “Valle del Yabú” Agricultural Company in the municipality of Santa Clara, Villa Clara. Basic seeds of the commercial cultivars of common bean was used: ‘Cuba C 25-9-R’, ‘Delicias-364’, ‘CUFIG-110’, ‘CIAP-24’. Seven evaluations were carried out during the 70-day crop cycle, at 10-day intervals, considering the following physiological indicators: dry mass, leaf area, absolute growth rate, net assimilation rate, leaf area ratio and harvest index. All the variables evaluated in the cultivar ‘Cuba C 25-9-R’ reached significantly higher values than the rest of the cultivars. The dry mass, the leaf area and the ratio of leaf area per plant showed rapid growth from 10 to 40 days after germination, at which point their values began to decrease until reaching physiological maturity. The absolute growth rate showed an increase of 30-40 days after germination, at which point it portrayed negative values, while the Net Assimilation Rate in the same period showed a tendency to decrease. All the cultivars presented a high harvest index and agricultural yield, reaching the highest value ‘Cuba C 25-9-R

32-42

Authors: Yunel Pérez Hernández, Dayne Amaro Sánchez, Lenia Robledo Ortega, Marlene María Martínez Mora, Ana Julia Rondón Castillo

The objective of the present work was to determine the phytochemical and antibacterial characteristics of leaf extracts of five weed species located in Coliseo, province of Matanzas, Cuba. The collected leaves were washed, dried at 45 °C, then powdered. The extractions were carried out in ethanol 90 % and water. The presence of several secondary metabolites classes was determined and it was quantified the content of total soluble carbohydrates and proteins, reducing sugar and total polyphenols. The antibacterial activity of the ethanolic extracts was determined against Gram positive and negative strains. Data were statistically analyzed by using SPSS 15.0 over Windows. Simple ANOVA and Tukey ́s Multiple Range Test were used for comparison among the media of the treatments (extracts). The phytochemical study showed terpenoids, flavonoids, saponins, steroids, tannins, coumarins and cardiac glycosides in both ethanolic and aqueous extracts of the analyzed plants. The highest content of polyphenolic compounds was observed in Bidens pilosa and Euphorbia heterophylla. The ethanolic extracts of Ageratum conyzoides, Bidens pilosa, Momordica charantia and Euphorbia heterophylla showed antibacterial activity against Staphylococcus aureus and Proteus sp. The obtained results suggest a potential use of those species for the clinical treatment of infectious diseases in humans and animals as well and they represent sources of bioactive compounds.

53-59

Authors: Roger Alexander Pincay-Ganchozo, Ricardo Augusto Luna-Murillo, Kleber Augusto Espinosa Cunuhay, Hamiltón Omar Espinales Suárez

The present study aimed to evaluate the effect of chemical and biological scarification on the emergence and growth of Clitoria ternatea L. seeds. The following pregerminative treatments were used: soak in water for 12 h, soak in humic acid for 12 h, soak in humic acid for 24 h, soak in water at 80 ° C for 5 minutes and soak in 90% sulfuric acid for 45 minutes. The following variables were evaluated: percentage of emergence at 3, 6, 9 and 15 days after sowing, plant height (cm), from 30 to 75 days after sowing, on this last day Destructive sampling was used and root length (cm), root weight and forage biomass (g/plant) were evaluated. A tissue analysis was performed on the leaves at 30 and 75 days after sowing to determine the concentration of macroelements. The data were subjected to an analysis of variance and comparison of means by Tukey's test at the 0.05 level of significance. The results showed that when the seeds of C. ternateaare soaked with humic acids for 24 h, the emergence of the seeds improves, also in growth stages the height of the plants, root length, root weight and part increase significantly. In addition, the concentration of macronutrients in leaf tissues

71-80

Authors: Juan Almaguer López Código, Norma Barberena Fernández

An experiment was carried out during four harvests (two in the cold season and two in spring) with the objective of determining the N losses by leaching and volatilization as well as their dynamics in a Brown Grayish soil in the Central Cuban region at the Experimental Station of Soil “Escambray” in corn crop. Six N levels were applied (0, 60, 120, 180, 240 y 300 kg ha-1 of N) a third of which with ammonium sulfate when planting and the remaining 35 days with urea. Volatilization of ammonium in form of ammonia was determined using Nömmik’s method in levels 0, 120 and 240 kg ha-1 to 3, 7, 14, 21, 28 and 35 days after fertilization. The washing of NO3- and NH4+ was quantified using a lysimeter type Ebermeyer. Ammonia losses due to volatilization increased along with N doses in the two seasons, reaching its maximum level between the 3rd and 7th days after the second urea fertilization with values of 25 kg ha-1. NH4+ leaching was insignificant. while NO3- losses increased along with the doses and were approximately 13 % of the applied N reaching values of 47 kg ha-1 in the dose of 300 kg ha-1. It is concluded that in Brown Grayish soil the greatest losses due to ammonium volatilization occur with urea and the greatest leaching occurs in NO3-.

93-97

Authors: Elena Rodríguez Hernández

Botanical collections are the basis for floristic and taxonomic work; every study requires the collection and herborization of specimens. This report presents the curatorship and recovery work of the carpo-spermoteca of the Villa Clara Botanical Garden herbarium, available to visitors and for academic and research purposes. The samples were identified and disinfected, followed by cleaning and packaging in glass jars. The collection comprises 307 species from 46 botanical families distributed in approximately 200 genera; dry preserved samples predominate.The Fabaceae and Poaceae families are the best represented by the number of species, 51 and 40 respectively.

14-23

Authors: Carlos Alberto Sangoquiza Caiza1,2* Yosvel Viera Tamayo2 Carlos Fernando Yánez Guzmán3 José Luis Zambrano Mendoza3

Corn is one of the most economically important cereals in the world, ranking second after wheat. Among the great diversity of varieties of Zea mays L. that are cultivated in Cuba, is the "Tayuyo" variety. Currently, there are no studies that evaluate the effect of the salinity of this variety. Therefore, the objective of the present work was to evaluate the effect of saline stress on the growth of seedlings of maize variety "Tayuyo" under in vitro conditions. It was carried out at the Plant Tissue Cultivation Laboratory belonging to the Center for Plant Biotechnology Studies (CEBVEG) of the Faculty of Agricultural Sciences (FCA) of the University of Granma (UDG), Cuba. In which the range of tolerance to salinity of corn plants was evaluated in vitro using a basal culture medium (6 % agar and distilled water) with different levels of electrical conductivity (0, 2, 4, 6 and 8 dS m-1) adjusted with the NaCl reagent. For this research, an experimental design of random blocks was used with three replications where they evaluated; germination percentage, number of roots, length of the primary root, plant height, number of leaves per plant, weight of fresh matter and the index of tolerance to salinity was calculated. The results revealed that the evaluated plants are tolerant to salinity up to 2 dS m-1. In general, the increase in salinity levels caused a delay in germination but not in the germination percentage at eight days after sowing. On the other hand, the rest of the variables showed a downward trend with increasing salinity levels.

31-36

Authors: Alberto Espinosa Cuéllar, Jaime Enrique Simó González, Osvaldo Triana Martín, Orestes García Hernández

The research was developed at the Tropical Crops Research Institute, with the aim of defining the best planting distance of the banana clone 'Manzano INIVIT'. It was planted on a carbonated soft brown soil. Fourth plantation frames of 3.50 m x 2.00 m were used; 3.50 m x 2.50 m; 3.50 m x 3.00 m and 3.50 m x 3.50 m. The evaluations made were, plant height, pseudostem perimeter, number of leaves in flowering and harvest, bunch weight and agricultural yield. The height of the plant showed its lowest values in the intermediate distances. The thickness of the pseudostem presented the highest value with the distances between plants 3.50 m and 3.0 m of planting density. Regarding the number of leaves at flowering, there were no significant differences between the treatments. The number of hands ranged from 9 to 10 hands per bunch, the distance 3.50 m x 3.00 m being the lowest value compared to the other distances used. The number of fingers per cluster was 115 to 123, where the distance 3.50 m x 3.00 m reached the lowest values. Regarding the weight of the bunch, the highest weights were reached with the distance 3.50 m x 3.50 m. In turn, the best yields were obtained with the distances 3.50 m x 2.00 m and 3.50 m x 2.50 m, the values were 19.29 and 17.71 t ha-1

47-56

Authors: Enildo Osmani Abreu Cruz, Ramón Liriano González, Alejandro Aquino Arencibia, Jovana Pérez Ramos

The research was developed with the objective of evaluating the effect of QuitoMax® on the yield of garlic cultivation under organoponic conditions, clone “Chileno”, for this, four treatments were studied: T1 (control treatment, without the application of the product); T2 (100 mg ha-1); T3 (150 mg ha-1) and T4 (200 mg ha-1). The experiment was developed in the organoponic belonging to the Urban Farm, located at the University of Matanzas, a substrate made up of 80 % soil (red Ferralitic) and 20 % organic matter was used, arranged in a completely randomized design. Samples were carried out at 30 and 60 days after planting the crop to determine the agromorphological variables: number of leaves, height of the plants and diameter of the base of the bulb and at the time of harvest, the yield variables were measured: the weight of the bulb, its equatorial and polar width and the number of teeth. The behavior of the morphological and performance indicators did not allow to define in a significant way a stimulating effect of QuitoMax®, in the doses evaluated on the biological performance of garlic with respect to the control treatment, under the established study conditions. In the variables height of the plants and number of leaves, a positive response of the crop was evidenced in the period of greatest growth with the best response in the dose of 150 mg ha-1.

74-78

Authors: Yatniel Escobar Perea, Belyani Vargas Batis, Yordi Mauro Ramos García, Ernesto Jesús Rodríguez Suárez, Orledis Rodríguez Osoria, Rubert Rodríguez Fonseca

The objective was to evaluate some physical properties of the soil in four suburban farms in Santiago de Cuba. Soil samples were taken and the volumetric weight, apparent density, real density, porosity and humidity were determined. Among the farms, a similar statistical behavior of the evaluated properties was obtained. The volumetric weight varied from 1.18 to 1.32 g cm-3, the apparent density between 1.04 and 1.24 g cm-3, the real density from 2.27 to 2.59 g cm-3, the porosity ranged from 51 to 53 % and the humidity from 6.1 to 11.4 %.

14-22

Authors: Alejando Díaz Medina, Yasel López Pérez, Claribel Suárez Pérez, Lesly Díaz Suárez

The quality of coffee seedlings obtained in nurseries is a determining factor in the achievement of highly productive plantations. Was carried out an experiment in Tope de Collantes, with the objective to evaluate the effect of FitoMas-E and two proportions of organic matter in the substrate on the growth of coffee seedlings in the nursery stage. Was evaluated the effectiveness of four dose concentrations of FitoMas-E (0, 2, 4 and 6 ml L-1), and two soil proportions - organic matter (bovine manure) in the substrate (3:1 and 5:1), about the growth of the seedlings, with an experimental design totally randomized with bifactorial arrangement. The height of the plant, diameter of the shaft, foliar area and total dry mass of the seedlings to the were evaluated seven months after seeds were set down. The results evidence that the application of FitoMas-E it influences positively in the growth of the coffee seedlings, with increments of their efficiency, in the measure that the doses are increased independently of the conformation of the substrate. The dose of 6 ml L-1 was the most efficient and it was evidenced that with the application of the bioprepared it is possible to diminish the levels of organic matter in the substrate, without affecting the quality of the coffee seedling.

28-36

Authors: Alexander Calero Hurtado, Yanery Pérez Díaz, Elieni Quintero Rodríguez, Yainier González-Pardo Hurtado

The use of adequate plant densities can be a key and important factor to increasing rice productivity (Oryza sativa L.). Therefore, the objective of this study was to investigate the influence of four population densities (DP) on the growth and agricultural production of rice. The INCA-LP-5 cultivar was managed between April and August 2016. The treatments were distributed in a randomized block design, with four population densities (250,000, 350,000, 450,000 and 550,000 plants ha-1) and five replications. The effects of the PD were verified by observing the following parameters: evaluated the following indicators, plant height (cm), tiller number per hill, number of panicles per m2, number of grains per panicle, panicle length (cm), 1000 grains weight (g) and grain yield (t ha-1). The results indicated that the DP of 450,000 plant ha-1 showed the best results in rice productivity. These results were possible because the DP of 450,000 plants ha-1 increased the morphological and productive parameters in relation to the other densities studied. The findings of this study indicated that the use of optimal plant densities plays a fundamental role in the growth and productivity of rice, which leads to a sustainable development of the crop.

43-51

Authors: Nayivis Del Sol-Rodríguez, Dagoberto Guillén-Sánchez, Irán Alia-Tejacal, Porfirio Juárez-López, Victor López-Martínez

The production of fig (Ficus carica L.) in Mexico has become very important in recent years, due to the growing demand in the international market. The state of Morelos stands out as the main fig producer nationwide. The municipalities of Villa de Ayala, Tepalcingo and Axochiapan concentrate the highest productivity, however, serious affectations by some diseases such as rust caused by Cerotelium fici (Butler) Arthur have caused losses in crop yield. The objective of the work was to determine the incidence and severity of this disease, in two periods during the crop cycle. Representative samples with symptoms were taken in commercial plots of three municipalities in the state of Morelos. The incidence of the fungus and its severity were evaluated using a visual estimation scale, during February-March and August-October 2019. Six evaluations were made with weekly frequency during the cycle. The fungus was morphologically identified using taxonomic keys. The presence of C. fici uredospores was confirmed and it was determined that rust was present in both periods, with a higher incidence in the months of February and March (dry period). The municipalities of Villa de Ayala and Axochiapan, had the greatest affectations with 45 to 70 % severity.

61-65

Authors: Caridad González Fernández, Nereyda Mestre Novoa, Jorge L. Rodríguez Tapia, Doris Hernández Espinosa

In Cuba, the cultivation of acerola (Malphigiae marginata D. C.) is still very limited, although it is an attractive fruit with a pleasant taste and with a recognized nutritional value. The Information on the pests that affect this fruit in Cuba is scarce. From January 2015 to April 2016, periodic evaluations were carried out in the acerola plantation at the Scientific Technological Base Unit in Alquízar and in plants located in the town of La Lisa, Havana City. The presence of Cerococcus dekleiKosztarab and Vest (Hemiptera: Cerococcidae) is reported for he first time, causing damage to the foliage of the acerola.

72-82

Authors: Bret Gary Luque Zúñiga, Khiara Aliyah Bet Moreno Salazar Calderón , Teresa Margarita Lanchipa Ale

Agriculture during COVID-19 has been affected internationally, affecting food security. This article presents how COVID-19 has impacted on the system that makes up the activity of agriculture, this being the main source of food that supplies the population, generating income for small farmers and their families, which contribute to food security of the different countries of the world. The present study is a descriptive systematic review, based on theoretical contributions, the objective was to analyze the current situation of agriculture in relation to COVID-19 pandemic. The methodology consisted in the compilation of scientific articles and official publications in the public domain of academic, technological, scientific and governmental institutions. The results focused on: the impacts of COVID-19 on agriculture, concern for food security, social impacts on agriculture, and government commitment. Finally, it is considered that COVID-19 would generate impacts on agriculture and food security, this would bring a food crisis, and it is still rash to affirm the above because the pandemic has not yet ended.