Potencial bioherbicida de plantas e de fungos sobre o controle de macrófitas

Abstract

This research aimed to evaluate the bioherbicides potential of Eragrostis plana (grass anonni 2) and phytopathogens (fungi) on E. crassipes , Pistia stratiotes and Salvinia herzogii, free floating aquatic plants that limit the multiple uses of water, especially in anthropogenic or artificially built environments. In this context it was tested different concentrations of aqueous extracts from grass anonni 2 and prospected fungi isolated and multiplied in the microbiology laboratory of UFFS - Campus Erechim. The assessment of different aqueous extract concentrations of grass anonni 2 were based on the methodology proposed by the Brazilian Society of Science of Weeds – SBCPD, 1995 (Sociedade Brasileira de Ciência das Plantas Daninhas), and fungi by the disease severity using the descriptive scale of Horsfall- Barrett (CAMPBELL & MADDEN, 1990). The research used a randomized experimental design with three replications. Statistical calculations were performed with the aid of the software Assistat, 7.7 version. The obtained results were submitted to variance analysis (ANOVA) and subsequently the means of the treatment were compared by the Tukey test at 5% probability. The results showed low level of control, at doses and aqueous extract Eragrostis plana, with a strong possibility of having exercised photonics function and have contributed in the end supply of biomass in the experimental units. The group composed by the fungi (IFL, IFC, IFP and Phoma) was the one who presented the best results. E. crassipes , treated with fungus, obtained visual control levels ranging from 75% to 88%. The treatment with Phoma sp. of NRRL, obtained from the Bioprocess Laboratory of the Graduate Program in the Process Engineering - UFSM, has shown strong potential in the control of Salvinia herzogii and Pistia stratiotes, especially up to 15 DAT. Lastly, the obtained results show, as a general rule, the potential of the treatments performed and the effective contribution in the management and in the control of aquatic weed.