Effect of cell concentrations and cell-free filtrates of Pseudomonas fluorescens (Isolate Pf₁) on Hatching and Mortality of Rotylenchulus renifomis*

Studies were conducted in vitro to evaluate the efiicacy of cell concentrations at varying levels of 10⁴ to 10¹⁰ cells/ml and undiluted cell-free filtrate (S) and its dilutions S/4, S/8, S/16 and S/20 of Pseudomaonas fluorescens isolate Pf₁ on hatching and mortality of Rotylenchulus reniformis at 3 exposure periods. Both bacterial cellconcentrations and cell-free filtrates of Pf₁ isolate suppressed egg hatching and viability of immature females/males of the nematode. However, significant mortality of the nematode was achieved at concentrations of 10⁸ cells/ml and above but other concentrations (10⁴ to 10⁷) were at par with control (water). A negative correlation was evinced between levels of cell concentrations/cell-free filtrates and hatching but a positive one with mortality of the nematode.