Etude in vitro et in vivo du pouvoir insecticide de l'extrait de Thymus vulgaris et Datura stramonium vis-à-vis de Tuta absoluta

Abstract

Plant extracts are of great interest as a potential source of biologically active molecules. It is in this context that the present study, which focuses on the valorization of extracts of botanical origins in the field of plant protection, is included. Two plants are used to prepare the extracts; the medicinal plant thyme and the toxic plant stramony. The extracts are obtained by the superheated water technique, an innovative technique based on the physicochemical properties of water that are modified by the increase in temperature and pressure. The efficacy of the extracts is assessed against Tuta absoluta (Meyrick) the tomato leafminer, which is considered a serious threat for tomato production in Algeria. The toxicity of plant extracts is estimated in vitro and in vivo on Nada F1 variety tomato plants. The biological tests showed that D. stramonium extract had a remarkable mortality rate exceeding 85% and 58% for T. vulgarisL extract. three days after treatment. A gradual decrease of the rates of infestation by the leafminer is observed after spraying of these extracts, the rates recorded one week after treatment are of the order of 10% for the plants treated with the Datura extract and 6.66% for the plants. treated with thyme extract.