A sustainable strategy for mass production of endophytic Trichoderma virens 159c and assessment of biological control properties via in vitro and in vivo assays

Abstract

Trichoderma has been used as a biological control agent against plant pathogens and has since become a research focus for alternative chemical fertilizers. However, the use of potato dextrose agar as a carrier of Trichoderma for mass production is less suitable for field application due to its short shelf life and high cost. Therefore, this research attempts to utilize agricultural waste from oil palm to generate a high number of good-quality T. virens 159c spores and to evaluate its antagonistic activity against Ganoderma boninense which causes basal stem rot disease in the oil palm. The formulation, optimized with palm kernel cake and palm pressed fibre supplemented with nitrogen and carbon sources, presented a significant 2.6-fold increase in total count of spores produced compared to the individual substrate. Enzyme analysis showed that the formulation produced higher levels of lytic and degrading enzymes, especially chitinase, which increased almost 3-fold compared to culturing only on PPF. Disease severity index (DSI) of oil palm seedlings using visual inspection and cross-section of the bole was evaluated for each treatment. The results showed that the plants inoculated with the T. virens 159c formulation had the lowest DSI, exhibiting only 18.3% visual DSI and 17.4% bole DSI, which was 37.3 % and 37.1 % significantly lower compared to the control respectively. The present findings showed that the development of a sustainable Trichoderma formulation producing good-quality spores as a potential prophylactic treatment to slow down disease development in the oil palm caused by G. boninense.