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El empleo de los bioestimulantes en la agricultura ha crecido en los últimos años, como una práctica agroecológica importante. La Spirulina y la vinaza poseen propiedades que favorecen el crecimiento y desarrollo de los cultivos, mejorando así la calidad nutricional de los mismos. El objetivo del presente trabajo fue determinar el efecto de un bioestimulante, compuesto por una suspensión acuosa de jalea de Spirulina y vinaza, aplicado solo o en combinación con otros bioestimulantes, en la producción de granos en el cultivo del frijol. Para esto, se montaron dos experimentos con el cultivar 'Inqueño'. En el primero se realizaron dos aspersiones foliares con dos dosis equivalentes a 3,5 y 7 L ha-1 del nuevo bioestimulante y en el segundo, se realizaron también dos aspersiones, la primera con el nuevo bioestimulante (2,5 L ha-1) y la segunda se efectuó con el nuevo bioestimulante a igual dosis o con Quitomax® o con la combinación de ambos. La aplicación del nuevo bioestimulante, a base de Spirulina y vinaza estimuló la productividad del frijol común, pero los resultados fueron más prominentes cuando se aplicó en combinación con el Quitomax® y se biofertilizó con Azofert®, que podría constituir una alternativa eficiente para incrementar el rendimiento de este cultivo. [ABSTRACT FROM AUTHOR]

La conservación de los productos hortofrutícolas en la postcosecha es un tema de vital importancia debido a las grandes pérdidas que se generan durante la comercialización interna de un país, así como en la exportación. Estas pérdidas se deben al deterioro microbiológico y fisiológico, a un proceso de recolección inadecuado, al empleo de empaques no adecuados y a vías para la transportación insuficientes. El empleo de recubrimientos biodegradables en forma de películas constituye una alternativa que permite disminuir estas pérdidas. Los recubrimientos biodegradables generalmente están compuestos por carbohidratos, proteínas y lípidos de forma individual o combinados entre sí. Estos recubrimientos constituyen una barrera semipermeable al vapor de agua, el dioxígeno (O2) y el dióxido de carbono (CO2) entre los frutos y la atmosfera circundante. De manera general retardan el proceso de senescencia y el crecimiento microbiano en la superficie del fruto, lo que permite preservar la calidad y facilitar la distribución y la comercialización de estos. Por las potencialidades y la importancia que este tipo de tecnología presenta en la actualidad, en nuestro contexto nacional se realiza esta revisión, teniendo en cuenta los principales componentes empleados en la obtención de estos materiales, la aplicación práctica en productos hortofrutícolas y los principales análisis que se realizan para su caracterización. [ABSTRACT FROM AUTHOR]

Beans, inside legumes, stands out for the high human consumption and, in Cuba, this legume is part of the population basic diet. Hence, to look for alternatives that allow stimulating grain production and therefore, increase the satisfaction of consumer demand, constitute a necessity. The aim of this paper was to determine whether seed application of QuitoMax® or Biobras-16® products, increases the plant yield of two biofertilized beans cultivars. The experiment was performed at Unit of Basis Science and Technology "Los Palacios". Seed sprayings with QuitoMax®, Qm (500 mg L-1) or Biobras-16®, BB-16 (0,05 mg L-1), before inoculation with Azofert® biofertilizer, Az, were made. Seeds were placed to Hydromorfic Gley Nodule Ferruginose Petroferric soil and four treatments (100 % N, control, Az+30 % N, Qm+Az+30 % N y BB-16+Az+30 % N) by cultivar were constituted. At the harvest time, the following evaluations: shoot, legume and grain dry weights, legume and grain number per plant, grain number per legume, fresh weight of 1 000 grains and practice yield, were made. Results showed Azofert® inoculation substituted 70 % of nitrogen fertilizer used without affecting crop yield. Besides, seed sprayings with Biobras-16®, before Azofert® inoculation, increased significantly crop yield, in both cultivars, compared to control treatment with 100 % nitrogen fertilizer. [ABSTRACT FROM AUTHOR]

Biofertilizers use in agriculture allow to ensure culture productivity, reducing chemical fertilizers and cost. Azofert® is a bioprepared composed by rizobia strains, with a positive effect on biological nitrogen fixation. Biobras-16 and Quitomax are natural bioactive products, considered as biostimulants which help plant to face various kinds of stresses and increase yields; however there is no information about the effect of the application of these biostimulants to seeds before biofertilizer inoculation on bean crop. The objective of this work was to determinate the Biobras 16 and Quitomax effect on nodulation and growth of common bean biofertilized with Azofert®. Two concentrations of Quitomax and Biobras-16 were applied on seeds the day before sowing and with Azofert® at the sowing moment, then they were put on Ferralític Red Lixiviated típic éutrico soil. 35 days after sowing were determined in ten plants by treatment: number and dry weight of nodules, shoot and root length and dry weight. Determination of leaf chlorophyll, nitrogen and phosphorus were also made. The results showed that application of specific concentration of Biobras-16 and Quitomax plus Azofer®t inoculation; stimulate, in a general way, the growth of plants; mainly with Biobras-16, which also increased leaf chlorophyll and nitrogen contents. [ABSTRACT FROM AUTHOR]

The chitosan is widely used in agriculture for having a strong fungistatic effect, also it has other properties such as extending the post harvest life of fruits and vegetables and stimulating the plant growth, among others. However, the use of this biopolymer for inducing salinity tolerance has been few studied, so the objective of this work was to check if chitosan-treated seeds are able to reverse the effects caused by salinity in the rice seedling growth and some biochemical indicators associated to this response. To do this, rice (Oryza sativa L.) seeds variety INCA LP-5 were treated for 24 hours with different concentrations of chitosan (0, 100 and 500 mg L-1). The germinated seeds were transferred to pots containing diluted Hoagland nutritive solution supplemented or not with NaCl 100 mmol L-1 and they were placed in a growth chamber with controlled conditions. The growth and biochemical indicators were evaluated eleven days after stress treatment. Seeds treated with chitosan 100 mg L-1 stimulated shoot length and dry matter in saline medium grown seedlings and lowered malondialdehyde and increased proline levels. Both chitosan concentrations enhanced the activities of catalase and peroxidase enzymes, although a higher effect was obtained with chitosan 500 mg L-1. [ABSTRACT FROM AUTHOR]

Some chemical properties of metal adsorption by chitosan are evaluated in this research work. Thus, the power of chitosan adsorption by Cu2+ metallic ion was comparatively studied at different pH values and stirring times. The adsorbed Cu2+ ion content was determined by atomic absorption, pH 5 being the most appropriate one for its adsorption. On the other hand, several trials were performed to analyze the possibility of chitosan to protect tomato plantlets from toxic levels of Cu2+, so proving a bigger root growth and a height decrease of plants treated with the product, effects counteracting toxicity by Cu2+. [ABSTRACT FROM AUTHOR]

The present work was performed at the National Institute of Agricultural Sciences (INCA), with the aim of studying the effect caused by seed treatment with chitosan on the Amalia tomato plant growth. Chitosan was obtained at the Laboratory of Oligosaccharines from INCA; it has a deacetylation degree of 88±2.4 % and a molecular weight of 1.35x105. After seeds were treated with different chitosan concentrations (0, 1, 10, 100, 1000, 2000 mg.L-1) during two times (four and eight hours), they were placed in Petri dishes and five days later, they were put in polyeturane trays. After 22 days, 22 plants were selected to evaluate plant height, stem diameter, root length and dry weight of each organ. Results showed, in general, that the best response was obtained when seeds were treated with 1 mg.L-1 chitosan during four hours, as this concentration stimulated significantly plant dry weight, although the other indicators were not modified. [ABSTRACT FROM AUTHOR]

In «Los Palacios» Rice Research Station, belonging to the National Institute of Agricultural Sciences (INCA), the effect of some chitin derivatives (chitosan and its hydrolysate) and its copper combinations on in vitro growth and sporulation of Pyricularia grisea fungus was studied. This fungus is the causal agent of Blast, the most important disease of rice crop in the world, whose conidia are the initial inoculum of such disease. One 8-mm-diameter mycelial disk was submerged for 15 minutes in each treatment and three, five and seven days later, the colony diameter was measured. Afterwards, conidial number was counted by a counting chamber and the colony sporulation distribution was observed. Results showed no significative effect of chitosan and its hydrolysate at 100 mg.L-1 concentration nor their combination with copper on Pyricularia grisea mycelial growth; however, they inhibited pathogen sporulation between 70 and 85 %; the few sporulation of chitosans was dispersed to colony periphery, whereas in the control, it was grouped in the center. These results permit to lead the possibility of using chitosans at low concentrations in the initial disease inoculum reduction in the field. [ABSTRACT FROM AUTHOR]