How to control rhizome rot in cardamom?

control

Drench nursery with 1 lit of Formaldehyde in 50 lit water for 3 sq.m. before sowing. Prophylactic drench with 0.25% Mancozeb or 1% Bordeaux mixture immediately after germination to control Pythium and 0.05% Carbendazim after 15 days to control Rhizoctonia.