P-068 - Activity of extracts from Chlorophyllum molybdites and spent substrate of Pleurotus djamor var. roseus on sporangia production by Phytophthora capsici

Phytophthora blight, caused by Phytophthora capsici, is a devastating disease of a wide array of vegetable crops within and outside the US. The success of P. capsici include its ability to produce structures allowing it to survive, spread, reproduce, and infect its hosts. Sporangia production is critical to the success of this pathogen. Management strategies that reduce the production of sporangia will help mitigate Phytophthora blight. Numerous studies have shown the efficacy of various biological extracts on P. capsici. This study was conducted to determine the effects of basidiocarps and mushroom spent extracts on the production of sporangia by P. capsici. Basidiocarps of Chlorophyllum molybdites and spent mushroom substrate (SMS) of pink oyster mushroom were air dried, ground into a powder, and extracted with deionized water. Extracts at 1, 5, and 10% concentration were prepared, and 25 ml of each extract was dispensed in petri plates, along with three 1-cm mycelium plugs of P. capsici grown on V8-agar medium. Petri plates containing only deionized water served as control. The petri plates were maintained at room temperature for 4 days, observed, and rated for sporangia production on a scale of 0-4 (0=no sporangia; 4= >250 sporangia/plug). The greatest numbers of sporangia were observed on control plugs, followed by the 1% SMS, 5% SMS and 5% C. molybdites. No sporangia were observed in the 1 or 10% C. molybdites, or the 10% SMS.