Biological Control Of Ceretocystis Paradoxa Dade C.Moreau Causing Black Rot Of The Oil Palm (ELAEIS GUINEENSIS JACQ) Sprouted Seeds Using Trichoderma Spp

ABSTRACT

Biological control of Ceratocystis paradoxa using Trichoderma spp. were conducted on oil palm spouted seeds. Eighteen spp. of fungi belonging to ten genera were identified as fungi associated with diseased sprouted seeds. Out of these genera, Aspergillus spp. occurred most frequently and in relative abundance at 25.9%, Trichoderma spp. (23.4%), Ceratocystis paradoxa (11.1%), Fusarium spp (9.9%), Penicillium spp. (8.7%), Rhizopus sp. (7.4%) and Curvularia sp. (4.9%) respectively. Pestalonia, Pythium and Saccaramyeopsis spp. were the least frequent (2.5%). Only C paradoxa proved pathogenic. Temperatures above 30°C increased infection while below 15°C infection rates were reduced. Histopathological studies revealed that, growth in host cells led to brown coloration, maceration and disintegration of cells within six days. Benlate solution and crude Icaf extracts of Azadirachta indica, Aculya wilkesium, Curicu paprya and Ocimum grutissimum roduced the growth of C paradoxa with increase in concentrations at 100% and 70%. However, after 14 days incubation only 0 gratissimum exhibited better control when compared to others. Trichoderma viride was identificd as a mycoparasite against Ceratocystis paradoxa. Firm attachment on C. paradoxa spores resulted in penetration by 7. viride, impregnated conidia were found dead. Benlate solution and extracted water-soluble compounds from T. polysporum and T. viride significantly reduced the growth of C. paradoxa at high concentrations (100% and 70%) compared to other Trichoderma spp. Metabolites released from 7. viride, T. polysporum and T. hamarum against C paradoxa had similar fungistatic effects except metabolite from 7. aureoviride.