Antifungal Activity of two Botanical Extracts on Rose Crop (Rosa L. Sp.), Against Sphaerotheca Pannosa Var. Rosae

Powdery mildew (PM) caused by the fungus Sphaerotheca pannosa var. rosae is the most widespread and economically important disease affecting the commercial sector of the rose production in Ecuador. Its incidence is influenced by the environmental agents and is affecting the aerial parts of the rose: stems, leaves and bottoms. The present study investigates aqueous and alcoholic botanical extracts of Ocotea quixos and Piper carpunya as alternatives to agrochemicals. For this reason, an in vitro evaluation has been developed for the antifungal activity of the leaf extracts of these two plants. The alcoholic extracts of P. carpunya and O. quixos and the aqueous ones of O. quixos, demonstrated the most efficient biological control against the fungus S. pannosa. The second step of the experiment consisted of applying in an in vivo experiment the efficient plant extracts resulted from the first in vitro tests. The application consisted in three doses for eight days during two cycles of rose cultures. It was evaluated the control level during four periods of time (15, 30, 45 and 60 days), based on the level of visual scale of damage on the leaves, stems and buds, noted with values from 1 to 5. The results demonstrated the efficiency of the extracts to prevent and control the fungus infection in rose culture and a further use as part of the biological control.