Avaliação do potencial bio-herbicida do fungo trichoderma koningiopsis

Abstract

The use of bioherbicides stands out for the great potential in the control of weed plantas with low residual capacity, which makes them important substitutes for pesticides in agricultural production. The objective of this work was to study the fungus Trichoderma koningiopsis on its bioherbicide effects nthe physiological, biochemical and morphological characteristics of weeds and grown ingreenhouse, as wellas its interaction withsynthetic herbicides. The tests were conducted in the laboratory and greenhouse linked to the Agroecology laboratory of the Federal University of Fronteira Sul, Campus Erechim/RS, between 2019 and 2020. The trials were conducted in a completely randomized experimental design. Initially the fungus T. koningiopsis was evaluated for exposure to different concentrations of synthetic herbicides, by the disc-diffuse method; Subsequently, fungal biomass was quantified and enzymatic analysis was performed for enzymes of amylase, cellulase, lipase and peroxidase n the bioherbicide in optimized medium produced at the base of the fungus; The bioproduct was sprayed with manual spray in the bioindicator plant of the cucumber; Andin weedsand winter crops(ryegrass, turnip and wheat) and summer (dairy, papuã and soybean),the effects of bioherbicide were tested with interaction of three commercial herbicide formulations with mechanism of actionof EPSPs (salof ammonium, sal isopropylamine and salpotassium), in the evaluation of the effects on plants were evaluated visual, morphological and physiological characteristics. The fungus T. koningiopsis has been shown to be resistant to the recommended or lower doses when exposed to the synthetic herbicides of Poquer (Cleotodin), Accent, Clorimuron (Classic), Glifosato (Shadow, R. Original, R. WG, Zapp Qi®), 2,4-D (DMA), Glufosinato de amônio (Finale), Gramoxone (Paraquate), Sulfotrazone (Boral® 500 SC), Fomesafen (Flex®), Saflufenaciz (Heat) and Atrazina + Simazina (Primatop® SC). Effects of bioherbicide on cucumber plants showed efficiency of the extract when applied with the presence of fungal biomass causing the death of up to 80% of the plants, when associated with Zapp Qi® the control was 100%, and the bioproduct was biologically safe by the worm escape test to evaluate its ecotoxicity. The synergistic effects on the interactionof the fungus combined with the commercial products Glyphosate (Roundup Original, Roundup WG and Zapp Qi®), which caused, after 16 days, irreversibledamage to dairy and papuã weeds, with the total death of plants at doses above 70% of synthetic herbicides associated with bioherbicide. There were no harmful phytotoxic effects on soybean crop. The development of newpest control alternatives is essential for maintaining agricultural yields and reducing the negative effects of pesticide residues on the environment.