Lab 8

Objectives

 1. To observe the antagonist effect of Trichoderma harzianumagainst Ganodermaboninense using dual-culture technique. 

2. To calculate the Percentage Inhibition of Radial Growth (PIRG) of Ganoderma boninense. 

Materials 

• Trichoderma harzianum culture

• Ganoderma boninense culture

• Potato Dextrose Agar (PDA)

• Scalpel and forceps

• Bunsen burner

• 70% ethanol

Procedures

1. Trichoderma harzianum and Ganoderma boninense fungi were prepared or isolated from pure cultures one week earlier during the laboratory session.

2. An agar disc (5mm) was cut from 7-day-old PDA culture plates of the G. boninense isolate and placed at the periphery (end) of a new PDA plate. The fungus was allowed to grow for 4 days at room temperature.

3. After 4 days, an agar disc (5mm) of T. harzianum was placed 1 cm away from the periphery, at the opposing end of the same PDA plate.

4. Three replications of the dual culture plates were prepared for optimum results.

5. In control PDA plates, only a G. boninense disc was placed at the periphery (end) of the PDA plate, without the presence of the antagonist (T. harzianum).

6. The inoculated plates were incubated for 5 to 7 days at room temperature.

7. The suppression effect of T. harzianum on the G. boninense isolates in the dual culture plates was observed.

8. The Percentage Inhibition of Radial Growth (PIRG) of G. boninense was calculated by using the formula

Results

Calculation

Discussion
In this study, we explored the potential of Trichoderma harzianum as a biological control agent (BCA) against Ganoderma boninense, the pathogen responsible for Basal Stem Rot in oil palms. Using the dual-culture method, we observed that T. harzianum effectively suppressed the growth of G. boninense, as evidenced by the percentage inhibition of radial growth (PIRG) calculations. After incubating the cultures for 5 to 7 days, it became clear that T. harzianum hindered the pathogen's growth compared to control plates, where G. boninense spread freely. This finding supports previous research that shows T. harzianum is capable of controlling a range of plant pathogens such as Fusarium spp., Rhizoctonia spp., and Alternaria spp., employing strategies like nutrient competition, antifungal metabolite production, and direct parasitism. T. harzianum is well-suited for this purpose because of its ability to grow rapidly in diverse environmental conditions, and it also produces enzymes that break down the cell walls of pathogens, further limiting their spread. The clear inhibition zones observed around T. harzianum in the dual-culture plates highlight its effectiveness in combating Basal Stem Rot in oil palms, offering an eco-friendly alternative to chemical fungicides. Other fungi such as Trichoderma viride, Beauveria bassiana, and Metschnikowia spp. have also been identified as potential BCAs, using various methods like direct antagonism, competition, or the production of toxic substances to control plant pathogens. Overall, T. harzianum emerges as a promising biocontrol agent for managing G. boninense and reducing the impact of Basal Stem Rot disease in oil palms, though further research, especially field trials, is needed to fully understand its effectiveness in practical agricultural settings.

Conclusion
To sum up, Trichoderma harzianum has shown great promise as a natural solution for controlling Ganoderma boninense, the pathogen behind Basal Stem Rot in oil palms. The dual-culture experiment revealed that T. harzianum effectively inhibits the growth of G. boninense, suggesting it could play a crucial role in managing this damaging disease in an environmentally friendly way. The fungus seems to use several strategies to fight the pathogen, such as competing for nutrients, producing natural antifungal substances, and even attacking the pathogen directly. These results highlight T. harzianum's potential as a biological control agent for various plant diseases, offering an alternative to chemical treatments. Given its resilience and ability to suppress harmful fungi, T. harzianum could be a valuable tool in sustainable farming practices, especially in oil palm plantations. However, further research, including trials in real-world conditions, is necessary to fully understand its effectiveness and ensure its practical use in agriculture.