Atividade in vitro sobre Sclerotinia sclerotiorum, indução em mecanismos bioquímicos de defesa e controle de mofo branco em feijoeiro (Phaseolus vulgaris L.) por soluções homeopáticas

Abstract

The common bean (Phaseolus vulgaris) is one of the main products of national agriculture and can be affected by many diseases such as white mold, incited by the fungus Sclerotinia sclerotiorum. This study aimed to verify the antimicrobial activity of homeopathic drugs against S. sclerotiorum, the induction of defense-related enzymes, as well as the phytoalexin phaseolin and the control of white mold in common bean plants. As treatments were used the homeopathic solutions Phosphorus and Calcarea carbonica, being the hydroalcoholic solution 30% (ethanol) the control treatment. The following variables were evaluated: number of sclerotia, mycelium growth and mycelial mass, in the in vitro assays; in the in vivo assay, disease progression and percentage of dead plants; and in the biochemical analyzes the phytoalexin phaseolin formation and the activity of the enzymes peroxidase, polyphenoloxidase, catalase, phenylalanine ammonia-lyase and β-1,3 glucanase. Both homeopathic solutions were dynamized in 6CH, 12CH, 24CH, 36CH and 48CH in in vitro, in vivo and phytoalexin induction assays. However, for evaluation of enzymatic activity, were only used the dynamizations 12CH and 48CH of homeopathic solutions, to be those which showed satisfactory results for the control of white mold in bean plants. In all evaluations, the homeopathic solutions Phosphorus 12CH and 48CH and Calcarea carbonica 12CH and 48CH were effective for the control of white mold in bean plants as well as for the induction of defense enzymes.