Bioestimulante à base de algas marinhas e ácidos fúlvicos como atenuador do estresse salino em melão

Abstract

The scarcity of quality water has led to the increasing use of low quality water (saline) on agricultural properties in irrigation management. However, the response of plants to salinity varies depending on several factors, whether genetic or environmental, impacting the growth and development of crops. Various methodologies have been used to alleviate salt stress in plants, including the use of biostimulants. Seaweed extract (Ascophyllum nodosum L) and fulvic acids stand out among the formulations of some biostimulants, demonstrating potential in optimizing crop performance in the field. Therefore, the present work aimed to evaluate the effect of a biostimulant based on seaweed (Ascophyllum nodosum L) and fulvic acids (commercial product: FH attivus), in mitigating saline stress in Goldex F1 melon. The experiment was conducted in a greenhouse belonging to the Department of Plant Science at the Federal University of Ceará, between the months of September and November 2023. The design used was completely randomized (DIC) in a factorial scheme (3 x 2) with four replications. The treatments consisted of: T1: without application of biostimulant; T2: with two biostimulant applications and T3: with three biostimulant applications. T4 (With and without salt stress): characterized by the absence of application of the biostimulant. T5 (With and without saline stress): treatment consisted of without introduction of salinity and with a salinity of 4.0 dS m1 and two applications of biostimulant. T6 (With and without saline stress): treatment consisted of without introduction of salinity and with salinity of 4.0 dS m-1 and three applications of biostimulant. Biometric (height, number of leaves, stem diameter and growth rate), physiological parameters (gas exchange and chlorophyll a fluorescence) were evaluated in three phenological phases: beginning of the vegetative stage, beginning of flowering and beginning of fruiting. The biostimulant was efficient in mitigating the negative effect of salinity on the vegetative phenological stage. The management of biostimulant application with 2 or 3 applications in the presence or absence of salinity did not have major variations, suggesting the application of 2x as being recommended. Plants in the absence of salinity responded more satisfactorily to biostimulant application management.