Author : Durante, Wenceslao S.

Summary : This study was conducted to determine some essential physiological factors that enhance vigorous growth of Pleurotus sajor-caju (Fr.) Singer. A Complete Ramdomized Design (CRD) was used in this study and each study was conducted three times. Means of the different treatment of each parameter was compared using Least Significant Difference Test (LSD). Results revealed that fastest growth of mycelial colony occured in continuous darkness and red light. White light of a shorter wavelength (400 nm) was more effective during the first week of fruiting. However, red light with a longer wavelength (680 nm) had a more pronounced effect towards the last weeks of fructification. Two minutes exposure to ultraviolet (UV) radiation twice daily (9:00 a.m. and 2:00 p.m.) also enhanced mycelial colony growth. Among the nitrogen sources used, only ammonium nitrate (0.01 percent concentration) induced mycelial colony growth of P. sajor-caju. Potassium nitrate and urea, both at 0.01 percent concentration, considerably favored fructification. Low-temperature incubation (10-15 degree C) of the culture improved the viability of the vegetative mycelial of this mushroom and survival of five-month old stock culture. The best mycelial colony growth was obtained in rice bran decoction (50 percent concentration) but the most number of fruit bodies of P. sajor-caju was from malt extract agar (control).