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.