Araucaria angustifolia and Picrasma crenata extracts as potential agents for the control of phytopathogenic fungi of agricultural interest

Abstract

To expand knowledge about native species in southern Brazil, different types of extracts from the thin vinaceous bark of A. angustifolia and fragments of branches of P. crenata were evaluated. These were crushed and kept for fifteen days in contact with hydroalcoholic solutions at 70 % v/v and ethanolic (96 % v/v), seven days in the cold aqueous extract, and through the decoction process for 10 min. Afterward, they were evaluated at concentrations of 1.0 %, 2.5 %, 5.0 %, 10.0 %, and 20.0 % v/v on the mycelial development of the phytopathogenic fungi Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotinia sclerotiorum. The levels of phenolic compounds and total flavonoids were evaluated, and the alcoholic extracts of A. angustifolia had the highest total phenolic content. The main phenolic compounds identified in the P. crenata extract were resveratrol, followed by herperidin, rutin, ferulic acid, and kaempferol, and the main chemical compounds identified in the extracts of A. angustifolia were quercetin, rutin, ferulic acid, kaempferol, and gallic acid. A. angustifolia extracts and P. crenata, during the decoction, were more effective in controlling the phytopathogens C. gloeosporioides and B. cinerea from a concentration of 5 % v/v. The fungus S. sclerotiorum was moderately inhibited in hydroalcoholic extracts at 70 % v/v of P. crenata and A. angustifolia at 1.0 % and 2.5 % v/v concentrations. Effectively controlling these phytopathogenic fungi of agricultural importance confers importance on the conservation of these native species of socio-biodiversity in the Atlantic Forest in southern Brazil.