Growth and sporulation of Alternaria dauci e Alternaria solani in culture mediaAlternaria dauci and A. solani are two phytopathogenic fungus species known for difficult sporulation in culture media. This hampers artificial inoculations and, consequently, affects the selection process of carrot and tomato genotypes resistant to the diseases caused by these fungi. This study had the objective of verifying the influence of some factors applied during incubation on mycelia growth and sporulation of the two fungus species. Different culture media (BDA, oat and V8), temperature (15, 20, 25, 30 and 35 ºC), light wavelengths during incubation (yellow, blue, white, NUV, green, and red), stress types applied to the colony (scratching, UV, microwave irradiation, and temperature of 100 ºC) and photoperiods (light / dark, respectively, of 24 h / 0 h, 22 h / 2 h, 17 h / 7 h, 12 h / 12 h, 7 h / 17 h, 2 h / 22 h and 0 h / 24 h) were tested. Upon determination of the best factors, the method developed in this study was compared to the traditional procedure (BDA, 25 ºC, 12 h white / 12 h dark light and scratching of the colony), with different isolates of both species. Results indicated the V8-agar media and a temperature of 25 ºC as most favorable for growth and sporulation. The different wavelengths had a marked influence on sporulation and NUV was the most stimulating. All applied stress types induced sporulation, but best results were obtained with scratching of the colonies. The 12 h light / 12 h dark photoperiod stimulated sporulation most. In general, longer dark than light periods after the stress of the colony favored sporulation. The procedure developed in this study consisted of incubation in V8-agar media, a temperature of 25 ºC, scratching of the colony and a 12 h light / 12 h dark photoperiod. This process is clearly superior to the traditional method for growth and sporulation of both species.