Growth Requirements of Pleurotus Ostreatus and Antagonistic Potential Against Rhizoctonia Solani

of Kufa for the period from 10/2/2019 to 1/7/2020. The aimed to identify changes in the nature and speed of growth of the oyster mushroom due to exposure to various environmental factors, including the type of nutrient medium, temperature, pH, and salinity (EC) and their interactions. The results showed that the growth of the fungus was significantly different with different food media, temperature, pH levels, lightness and salinity. The best nutritional medium for the growth of the fungus was the medium of wheat hay followed by barley hay medium and sawdust medium after 10 days incubation. The fungus has failed to thrive on the alfalfa medium. Regardless of the type of medium, 30C and pH 6 was the best growing condition. The oyster mushroom showed a high antagonism against pathogenic R.solani, especially at 20C o and 25C o . The results showed that the oyster mushrooms are sensitive to medium salinity (EC). The highest fungal radial growth (8.5cm) was recorded in PDA medium treated with distilled water, followed by PDA at EC 2dS/m which resulted in 8cm fungal radial growth. However, the oyster mushroom completely failed to grow on PDA with EC values of 14 and 16 dS/m.