Preparation of Pythium Inocula Using Bentgrass Seeds for Glasshouse Studies

Abstract

Inocula of Pythium spp. were prepared using bentgrass seeds in pots under greenhouse conditions and evaluated for the virulence on different plant species. The preemergence damping-off of spinach and melon was increased by increasing the density from 1.25 to 80% of bentgrass seeds colonized by P. spinosum or P. irregulare. The inoculum (2.5 or 5g/100g soil) was suitable for postemergence damping-off tests using P. ultimum, P. irregulare, Pythium 'group G' and P. spinosum. Concerning postemergence damping-off tests of melons, the inoculum (less than 5g/100g soil) was enough for P. spinosum, but 5-10g/100g soil was needed for P. irregulare. The inoculum (6g/85g soil) was applicable to damping-off tests of bentgrass seedlings.