INVESTIGATION ON PURPLE BLOTCH OF ONION IN INDIA
Aqueous extracts from all the plant species tested significantly reduced the conidial germination. Maximum reduction was observed in leaf extract of Polyalthia longifolia. It was followed by Eucalyptus citriodora, Datura alba, Ocimum sanctum, Punica granatum, Azadirachta indica, Ipomoea carnea, Tridax procumbens, and Tabernamontana coronaria.
The viability of conidia was reduced with increased duration of burying in the soil. Maximum conidial germination was observed in samples stored in the laboratory. Depth of burying also influenced the viability of conidia. Conidial germination increased with depth of burying to 7.5 cm after which there was a decrease in conidial germination. After 3 months of burying, conidia were still viable.