Rhizotonia root rot

Symptom

This disease typically occurs at the end of the rainy season and during the monsoon–winter transition in October and November. It spreads from the soil as well as through crop residues, particularly from the basal portions of plants. Under severe infection, up to 50% of betel vine plants may be damaged or lost. Since the disease primarily attacks the basal stem and underground root system, dark lesions develop around the collar region, and the stem tissues turn blackish. The roots gradually change to a reddish-brown color and become decayed. As the basal stem and roots are the main sites of infection, the leaves turn pale and eventually wilt.