Selectivity index and tolerance mechanism of commercial chickpea genotypes to the herbicide lactofen

• Grant number: 19/22830-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2020
• End date: January 31, 2021
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Ricardo Victoria Filho
• Grantee: Mateus Augusto Dotta
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Chickpea (Cicer arietinum L.) is an important legume for world food, but its production is limited by weeds due to the lack of herbicides registered for the crop in Brazil, reaching losses of up to 97% if are not controlled. Given this, the objective of the project is to evaluate the selectivity of six commercial chickpea genotypes to the herbicide lactofen; To estimate the selectivity indices of the genotypes as a function of the four weed species and to study the herbicide absorption, translocation, and metabolism in the crop. The experiments will be conducted in a greenhouse at the Department of Plant Production of ESALQ/USP and at the Ecotoxicology Laboratory of CENA / USP, both in Piracicaba, SP. First, to study selectivity indices, the chickpea genotypes and the four weed species will receive the following doses of the herbicide lactofen, 0, 11,25, 22,5, 45, 90, 180, 360, 720, 1440 and 2880 g ha-1 when they are in the 4-6 leaf stage, with visual evaluation at 14, 21 and 28 days after application. Subsequently, in the study of absorption and translocation, the herbicide 14C-lactofen will be applied to chickpea plants, being evaluated at 12, 24, 48, 96 and 192 hours after application, where the plants will be washed to remove the herbicide not absorbed and by autoradiography and tissue combustion, determined by translocation; For metabolism, the lactofen will be applied and evaluations will take place at 3, 24 and 72 hours after application, each of which consists of performing chromatography and radio scanner reading of macerated plants. Finally, the statistical analysis will be performed in the software R, using the dcr package. (AU)