Study of the Control of Fungus Occurring in Schizolobium amazonicum Seeds with the Use of Pyroligneous Extract

Abstract

Fungi are the main microorganisms present in seeds, constituting the main cause of deterioration and production losses. Among the health testing methodologies for detecting fungi in seeds, incubation tests under controlled conditions facilitate fungal growth and sporulation. Therefore, this work aimed to evaluate the efficiency of pyroligneous extract in the control of phytopathogenic fungi occurring in Schizolobium amazonicum seeds. Treatments consisted of exposure of seeds to pyroligneous extract for a period of five minutes at concentrations (0%, 1%, 2.5%, 5%, 7%, 10% and 12.5%). The treated seeds were placed in Petri dishes, lined with two sheets of filter paper, moistened with sterile distilled water. The experimental design was completely randomized, consisting of 7 treatments, with 9 seeds per plate and 10 replications per treatment, totaling 630 seeds arranged in 7 Petri dishes. The evaluation was performed 8 days later, with the aid of stereoscopic and light microscopy, where the fungal growth in each seed in the plates was verified for the incidence calculation and then the identification of these. Pyroligneous extract was found to be efficient in reducing the fungal incidence of the genera Fusarium sp. and Rhizoctonia sp., fungi considered important plant pathogens that could compromise seed quality and seedling establishment in the field. It also reduced the incidence of storage fungi capable of causing seed deterioration and consequent loss of vigor, such as Aspergillus spp. occurring in seed samples of S. amazonicum. However, Penicillium sp was not controlled by treatment of S. amazonicum seeds with pyroligneous extract up to 12.5% concentration.