PROCESS FOR OBTAINING BIOHERBICIDAL EXTRACT AND AGRONOMICAL APPLICABILITY

• Grant number: 24/05751-9
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2025
• End date: January 31, 2027
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Márcia Maria Rosa Magri
• Grantee: Márcia Maria Rosa Magri
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil
• Associated researchers: Patrícia Andrea Monquero

Abstract

The objective of the project will be to optimize the production of a microbial extract based on the yeast Torulaspora globosa (metabolites and/or metabolites and cells) for use as a bioherbicide. Furthermore, understand and evaluate the sensitivity of weeds and selectivity of different crops to extracts, determining the molecules and processes involved and the protocols for using the bioherbicide. To produce the extracts, different sources of carbon and nitrogen will be evaluated, in addition to the addition of tryptophan, for the cultivation of yeast. The extracts will be analyzed for indoleacetic acid (IAA) concentration, pH and titratable acidity. Furthermore, the extracts obtained under different conditions will be applied to seeds of three weed species, under in vitro conditions, for bioherbicide evaluation in germination control, using germination tests in Petri dishes with the following treatments (T): T1- control with distilled water; T2- yeast metabolites; T3- metabolites + yeast cells. The extract with the best result in this preliminary test will undergo metabolomic analysis to identify possible molecules with a herbicidal effect. This extract will be used in the following tests with the plants. 15 weed species will be evaluated in the laboratory, using seed germination tests in Petri dishes with the following treatments (T): T1 - control with distilled water; T2- yeast cells; T3- yeast metabolites; T4- metabolites + yeast cells; T5- AIA (at the same concentration identified in the extract). The weed species evaluated will be defined based on their importance as weeds and damage to different crops. The sensitive weeds in the laboratory test will later be sown in pots to determine the pre-emergent bioherbicide effect of the extracts when applied to soils with two different textures: clayey and medium texture. Additionally, weed plants (15 species) will be evaluated for sensitivity post-emergence, in a greenhouse. The treatments will be applied at the beginning of development (second pair of true leaves open or beginning of tillering), without or with different adjuvants (with different hydrophilic/lipophilic natures). Trials with pre- or post-emergence assessments of weeds will also be carried out with the agricultural crops soybeans, beans, corn, peanuts and cotton. Additionally, considering the importance of weed control alternatives for "minor crops" due to the restricted number of registered herbicides and the search for more sustainable production systems, the selectivity of the bioherbicide for leafy vegetables (lettuce, arugula, chives) will be evaluated. and parsley). The leaf surfaces of weeds and crops will be analyzed after applying the extracts post-emergence. (AU)