Evaluation of ash from some tropical plants of Nigeria for the control of Sclerotium rolfsii Sacc. on wheat (Triticum aestivum L.)

Eleven ash samples, from organs of nine tropical plants, were screened for their abilities to inhibit mycelial growth and sclerotial germination of a Nigerian isolate of Sclerotium rolfsii on agar and in the soil. Ten ash sam ples showed some activity against mycelial growth of S. rolfsii in vitro. A sh samples from Delonix regia stem wood, Mangifera indica leaf and Vernonia amygdalina leaf were most effective as each totally inhibited mycelial gro wth of S. rolfsii in vitro. Ocimum gratissimum leaf ash, D. regia wood ash and Musa paradisiaca flower bract ash inhibited sclerotial germination on a gar. Nine ash samples protected seeds against pre-emergence rot. Ash from M . indica leaf, V. amygdalina leaf and Azadirachta indica leaf protected see dlings against post-emergence infection. Eichornia crassipes ash, which was ineffective in vitro, offered some protection to seeds in soil against pre emergence rot. The study demonstrates potentials of ash samples from tropic al plants in control of S. rolfsii on wheat.