Bottom Rot – Rhizoctonia solani

Bottom rot Common name Bottom rot Causal agent It is a fungal disease caused by a fungus belonging to the genus Rhizoctonia. It affects various plants, including corn, radish, onion, and potato, but especially lettuce. Scientific name Rhizoctonia solani Symptoms & Signs Bottom rot disease is characterized by wilting and browning of the outer leaves. The leaf stalks and bottom of the veins also show reddish lesions, which gradually cover the entire leaf. The fungus infects the foliage and gives them a white and brown color. The infected tissue also oozes a brownish liquid from the infected tissues. Transmission The fungus spreads through spores which can be transmitted to healthy plants by means of wind, water, insects, or infected tools. Temperatures between 25-27 C, along with moist conditions, favor the growth of the fungus. Time of concern Early spring to late summer Common hosts Lettuce Onion Corn Bean Potato Cauliflower