Bioestimulantes na morfologia, fisiologia e qualidade de frutos de tomate submetido ao estresse hídrico

Abstract

Tomato is a vegetable of economic and social importance for Brazil. It adapts to different climatic conditions, however, it is sensitive to water stress that can cause damage to its development and productivity. In order to minimize the damages caused by water stress, biostimulants appear, which present in their composition substances whose function is to protect plants from biotic and abiotic stresses. This dissertation aims to evaluate the effect of biostimulants on the mitigation of water stress caused in tomato plants. The experiment was conducted in a greenhouse using a completely randomized design, in a 2x2x6 factorial scheme, with five replications. Two soil water conditions (50% and 100% soil water retention capacity), two application times (beginning of flowering and beginning of fruiting) and six bioestimulants (without treatment; Seed+; Seed+ + Crop+ 1x; Seed+ + Crop+ 2x; Crop+ 1x; Crop+ 2x). Photosynthetic parameters, morphological aspects and tomato fruit quality were evaluated. From the results obtained, it is concluded that in a protected environment the application of biostimulants, based on extracts of Ascophyllum nodosum, may be an alternative to synthetic plant stimulants, serving as a support for traditional fertilizers, as it has been able to revert stress damages in fruit quality of tomato. In addition, the use of biostimulants, increased the shelf life without losing the quality of the fruit. Regarding the photosynthetic parameters, the application of biostimulants kept the potential quantum efficiency index of photosystem II (Fv / Fm) close to normal, even when subjected to water stress. The application of biostimulants Seed+ and Crop+ were efficient in the control of lipid peroxidation, besides increasing the enzymatic activities in proportion to the increase of the doses of biostimulants. It is evident, the efficiency of the use of biostimulants, in plant protection, productivity and quality of tomato fruits under water stress.