Rhizolex 50 WP—a new fungicide to control the foot rot of betelvine (Piper betle L.) caused bySclerotium rolfsii Sacc.

Abstract

Rhizolex 50 WP O,O-dimethyl-O(2,6-dichloro-4-methyl-phenyl)-phosphorothioate, a new fungicide, was evaluated againstSclerotium rolfsii Sacc., the causal organism of foot rot of betelvine (Piper betle L.). The fungicide,in vitro, arrested mycelial growth and sclerotial germination ofSclerotium rolfsii at 50 ppm and above concentration, maximum effect being at 100 and 200 ppm for inhibition of mycelial growth and Sclerotial germination respectively. Two months old potted betelvine plants were inoculated with mycelial culture ofSclerotium rolfsii by soil mixing method. Fungicide was applied by drenching method in desired concentration and on desired date. Fungicide treated pots showed lower percentage of vine mortality than the check (no fungicide). There was no significant difference in per cent mortality of vines under 0·2 and 0·4% fungicide applied at same date however higher dose (0·4%) of fungicide applied at 2 days after inoculation had shown lower percentage of vine mortality as compared to the lower dose (0·2%) at 5 days after inoculation. Thus, both concentration of Rhizolex 50 WP and time of its application play an important role in the control of foot rot disease of betelvine.