Search

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. [ABSTRACT FROM AUTHOR]

The objective of this work was to determine the dispersing effect of salinity in a Gleysol petrogleyic soil of Artemisa, Pinar del Río, Cuba cropped with rice. The dispersing effect was determined from multiple lineal regressions obtained from the dispersion coefficient of the soils with the exchangeable sodium percentage (PSI), electric conductivity (EC) and ionic strength that provide the total and free ions during the years 1997 to 2001, to discern the contribution of the salinity indicators % Na+ (PSI), total ionic strength (It), free ionic strength (Il), electrical conductivity, and others un-considered factors to the dispersion of the soils. High average dispersion of these soils masked the effect of electrolyte accumulation, counteracting it, with exchangeable sodium showing dispersing effect in electric conductivity ranges of 2,01 - 4 dS.m-1 and aNa+.(aCa2+)-0,5 total 5,01 - 7 (mmol.L-1)0,5. [ABSTRACT FROM AUTHOR]

Hydrogeochemical patterns of groundwater of Matanzas Northern basin as related to drained geological medium were found. Chemical composition was estimated by means of electric conductivity and mathematical relationships. By means of linear model that cross or not through the origin of coordinates good fit was found for data presenting only one pattern in time; when the data show a discrete number of patterns better results were found applying a second degree polynomial model, but when the water shows many patterns data have to be previously separated by means of a pattern recognition method. In all cases good similarity was found between real data and those obtained by applying mathematical models. [ABSTRACT FROM AUTHOR]

This investigation was carried out in 3 bovine units of Santa Clara's municipality having a majority of crossbreed Siboney race aging 4 years and with manual milking supported by calves. There were collected total of 568 milk samples of each quarter from 142 apparently healthy cows, according to NC78-25(1987). These sample were tested for electric conductivity, salts, pH, redox potential, California Mastitis Test (CMT). There is a positive correlation among CMT and electric conductivity, pH and salts, meanwhile there is no correlation with redox potential. There is also correlation between electric conductivity and salts and no correlation between pH and redox potential. [ABSTRACT FROM AUTHOR]

A water management study in one irrigation system, its effect on the electric conductivity of soil saturation extract and rice yield was conducted at "Cubanacán" farm, pertaining to "Los Palacios" Rice Agroindustrial Complex, for three poorly rainy and three rainy seasons, whereas water management on nonsloping terraces did not show any statistical effects, either upon yield or electric conductivity. [ABSTRACT FROM AUTHOR]