ACUTE TOXICITY OF RESIDUAL HERBICIDES ON MACROPHYTES (Lemna minor)

• Grant number: 23/00759-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2023
• End date: April 30, 2024
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Patrícia Andrea Monquero
• Grantee: Bruno Barbugian Ramalho Siqueira
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

The use of herbicides with a long residual can influence the productivity of agricultural crops and terrestrial and aquatic ecosystems. Thus, the objective of this work is to evaluate the residual effect of the dose-response of the herbicides indaziflam, sulfentrazone, clomazone and tebuthiuron and their acute effects (LC50; CENO and CEO) in Lemna minor. The experiment will be conducted in the laboratory, in accordance with OECD (2002), toxicity standards (CL50;7d;CENO and CEO) to analyze the effect of herbicides at different concentrations, according to the USEPA ecotoxicological table (2017), on the crop of Lemna minor, and thus, evaluate mortality, plant size (cm), leaf size (cm), root size (cm) and fresh weight (g) for a period of 7 days. At the end of the work carried out in the laboratory, the data obtained regarding the acute tests will be evaluated the concentration that caused mortality (L. minor) to 50% of the organisms, which corresponds to the average lethal concentration (LC50), to later calculate and compare with the mean value presented in the laboratory's control chart (ABNT 2016). The LC50 will be calculated using the statistical method of Trimmed Spearman-Karber (p < 0.05), with the aid of the computer program Trimmed Spearman-Karber Method Version 1.5. To determine the CENO and CEO, the data will be submitted to analysis of normality (Chi-Square test) and homogeneity of variances (Bartlett test) and then analysis of variance, with Dunnett's test to verify the existence of differences between treatments.