Effect of light and aeration on the growth of Sclerotium rolfsii: A causal agent of stem rot of groundnut

Abstract

Groundnut (Arachis hypogaea L.) is an important oil seed crop in the world, belonging to the Leguminosae family. S. rolfsiiis a devastating soil borne pathogen in groundnut, which is becoming an economically important pathogen and has shown an increasing trend over the years.S. rolfsii was exposed to different light period and aeration in order to assess the mycelial growth and sclerotia development. Exposure of the pathogen to different light periods of alternative cycles of 12 hr light and 12 hr darkness resulted in the maximum mycelial growth and more number of sclerotia compared to other treatments. Mycelial growth was relatively fast and more number of sclerotia were observed in no sealed plates (control), where the complete air movement was allowed in the Petri plates, whereas in half sealed plates, moderate mycelial growth with less number of sclerotia were noticed. In complete sealed plates, the movement of air is restricted by sealing of plate with cello tape, where the fungal growth was relatively very slow, and there was no sclerotia formation even after 21 days of incubation.