Efeitos combinados da salinidade e do fungo (Trichoderma harzianum) no crescimento do pepino (Cucumis sativus L.).

Abstract

In Brazil, cucumber is well accepted in all Brazilian regions, including the Northeast Region. In this region, due to the semi-arid condition, it is common for low rainfall to occur, which together with the nature of the source material, generate abundance of saline soils and, consequently, water containing high levels of salts. This salinity compromises the production of cucumbers due to osmotic and ionic effects, which result in changes in the processes of water absorption, transport, assimilation and distribution of nutrients in the plant. Faced with this problem, techniques capable of improving the tolerance of plants with greater sensitivity to salinity have been sought. Among these, biological techniques such as the use of biostimulants have been gaining importance, due to their ability to stimulate the root development of plants and to alter the pH of the rhizosphere, thus reducing the deleterious effect of salinity on this crop. In this sense, the objective of the present study was to analyze the combined effects of salinity and the fungus Trichorderma harzianum on the growth and development of cucumber. The experiment was conducted at UFRPE/UAST, in Serra Talhada/PE, in a randomized block design with five salinity levels (TESTEMUNHA/T0: 0.02; T1: 1.2; T2: 1.4; T3: 2.0; T4: 2.4 dS m-1) with application of a commercial product based on Trichorderma harzianum, at 15 and 30 days after the beginning of salt application. The following were evaluated: number of leaves, leaf area, length of the main stem, number of flowers, number, diameter and length of the fruit, as well as root characteristics such as volume, surface area, length, dry and wet mass of the roots. The data allow us to infer that there is an influence of salinity in the cucumber culture. The biometric variables were directly influenced by the interaction of salinity and fungus, so that the plants treated when associated with the fungus T. harzianum revealed positive responses to salinity.