Regresar

INFLUENCE OF HUMIC SUBSTANCES ON THE PERFORMANCE AGRONOMIC ANALYSIS OF TWO RICE LINES SUBJECTED TO DIFFERENT SALINITY LEVELS AT GERMINATION AND EARLY GROWTH STAGES

Abstract:

The objective of this study was to evaluate the effect of humic substances on the tolerance of two rice varieties to salt stress, as well as to know the main characteristics of the scientific production registered in the Scopus database regarding the publication of research related to the variables Humic Substances, Agronomic Behavior of Rice, Germination Stage, and Initial Growth Stage. The experiment was carried out in a farmhouse at the Faculty of Agricultural Sciences of the UPSE, La Libertad-Santa Elena. Two rice varieties were used, INIAP FL-Arenillas and INIAP FL-1480, with medium salinity tolerance. The seeds were established in plastic containers containing three levels of salinity (0, 75 and 150 mM NaCl) and applying three concentrations of humic substances from vermicompost (0, 5 and 10 mg C L-1). Two phases were established. In the first phase, which lasted seven days, germination parameters (IVG, Vigor and %G) were evaluated, and in the second phase, initial growth (dry biomass and height) was evaluated at zero and five days after seed germination. Hoagland´s nutrient solution was used at half strength in the second phase, which was replenished daily. A tri-factorial DCA experimental design (3x3x2) was used, in which the following factors were evaluated: salt stress (ES), humic substances (SH) and variety (V), and the interaction between them, with a total of 54 experimental units divided into 18 treatments and three replications. The data obtained were statistically processed by the SISVAR 2019 program. The results were as follows: the FL-1480 variety presented greater resistance to the different levels of salinity applied to FL-Arenillas, the germination percentages of FL-1480 were higher by 9.78%, 19.56% and 22.22% when compared to FLArenillas for ES levels of 0, 75 and 150 mM NaCl respectively, the IVG and vigor presented similar behavior. It was observed that the application of SH reduced the percentage of abnormal seedlings significantly for the variety FLArenillas for all treatments under salt stress; similar results were observed for the variety FL-1480, although without significant results. In the case of FL-1480, doses of 5 and 10 mg increased the root growth of plants under ES levels of 150 mM NaCl. The FL-Arenillas variety showed a stimulating effect on root growth when doses of 5 mg C L-1 were applied to seedlings under salt stress levels of 75 and 150 mM NaCl. Applying humic substances from vermicompost to the two varieties reduced the number of abnormal seedlings obtained due to salt stress and increased total dry biomass and root length. Each variety had a specific SH dose for root length, the application of 5 mg C L-1 for FL-Arenillas at both ES levels, 5 and 10 mg C L-1 in FL-1480 for severe ES levels.