Division 9.3 F1

Inoculate by the same technique, five seedlings with an aqueous suspension of 10 ⁵ to 10 ⁶ cells per ml prepared from a 48 hr culture of a virulent biovar 2 strain of R. solanacearum as a positive control and with pellet buffer (Appendix 4) as negative control. Separate positive and negative control plants from the other plants to avoid cross-contamination.