On-Farm Evaluation of Trichoderma asperellum on the Suppression of Phytophthora megakarya Causing Pod Rot of Theobromae cacao in Nigeria

Abstract

Aims: The study examines the inclusion of biological control hitherto neglected, as part of the IPM strategies in a farmer participatory approach. Study Design: The experimental plots were set up within a completely randomized block experimental design with 3 replicates. Place and Duration of Study: The field trials were carried out in 2009 at Iloro-Idanre, Owode, Khalime and Bendeghe communities in the South -West and South - South of Nigeria. Methodology: The bio-control agents used (Trichoderma) was isolated from the leaves of cacao tree and natural forest reserve soils in Ibadan, Nigeria, the culture was stored and maintained in sterile distilled water on small plugs of modified potato dextrose agar. Five Treatments: Funguran OH, Trichoderma, Funguran OH (1) + +Trichoderma (5) times, Funguran OH (2) +Trichoderma (4) and Sterile distilled water were applied. Disease incidence ratings were taken after the each application till the end of the trial. Data were taken on number of pod and cherelles production, while number of damaged and Phytophthora pod rot were taken as total pod loss on each tree in each plot. Results: The pod productions in all the treatments differ significantly from the untreated control, likewise are the number of cherelles production in the treatments as well as the percent of Phytophthora pod rot incidence obtained from Iloro-Idanre. Both the number of pod production and cherelles production differ significantly in all the treatments and compare to the control. However, the pod production was highest (328) in trees treated with funguran application and the least percent (6.9%) of Phytophthora pod incidence was recorded in the same followed by that of Trichoderma and funguran combination and Trichoderma alone respectively in Khalime. The pod production in Trichoderma and untreated control do not differ significantly in Owode community though both differ significantly from other treatments. However, cherelles production of 111 cherelles was also highest in the untreated control but least in funguran treatment (37.0). Conclusion: Combination of spraying application of Trichoderma with copper based fungicides will drastically reduce the rate of application thereby lower the cost of fungicides incurred on disease control. Highest percentage incidence of black pod disease was however observed in the unsprayed control.