ABSTRACT

Aqueous crude extracts of ginger, ncem sccds, paw paw roots, bitter cola and leaves of Hyptis suaveolens at 5%, 10% and 20% concentration were tested for their cffects on the mycclial growth and sclcrotial germination of Sclerotiiul rolfsii on potato dextrose agar (PDA). The experiment was laid out in a 5 x 3 factorial in a completely randomized design (CRD) replicated three times. The results showed that at 20% concentration, cxtracts of ncem sced, /I. suaveolcnS, bitter cola and ginger significantly (P< 0.05) inhibited the mycelial growth of S rolfsii better than the extract of paw paw roots. Percentage inhibition was 71.1%, 64.6%, 62.6%. 59.3% and 36.6% respectively. Percentage sclerotia inhibitions at 20% concentration of the extracts were: neem seed (82.1%),f/.suaveolens (82.7%,), bitter cola (80.7%), ginger (70.2%) and pawpaw (49.0%). At 10% and 5% concentrations, the mycclial growth and sc\erolia germination of S. rolfsii was poorly inhibited. Inhibition of mycelial growth and germination of sclcrotia in S. rolfsii increased with increasing concentration of the extracts. ln the greenhouse studies polted soil in which tomato seeds were sown, was drenched with efficacious extracts at 20% concentration as well as suspension of captan and '/: harzianum. The results showed that drenching two days before inoculation with S. rolfsii gave similar disease reduction (56-67%) in all treatments. When the soil drenches were applied on the same day as inoculation, T, harzianum, necm sccd extracts, captan, H. suaveolens and ginger extracts significantly differed (P <0.05) from the bitter cola cxtract and the disease reduction value range from 40% -60%. Only neem seed extract, captan and T. harzianum significantly (P <0.05) reduced the damping-off disease giving disease reduction values of 52.5%, 57.5% and 64.7% respectively, at two days after inoculation with the fungus.