Alginate Encapsulation of Trichoderma harzianum as Biocontrol Agent against Brown spot Disease on Rice (Oryza sativa) in Vitro Assays

Abstract

Brown spot caused by Bipolaris oryzae is an important rice disease which can cause a reduction in yield and grain quality in Malaysia. The application of chemical agents in controlling the brown spot disease can cause undesirable effects such as residual toxicity, environmental pollution, and development of pathogen resistance to fungicides. Instead, biocontrol methods have to be developed to ensure environmental safety, the longevity of usage while effective methods of plant disease management. However, to the best of our knowledge, no research has been conducted about alginate encapsulation of Trichoderma harzianum. Therefore, the objectives for this study is to measure the performance of encapsulation of Trichoderma harzianum isolates in controlling the brown spot disease on rice. Alginate encapsulation was produced from conidial suspension by adding sodium alginate and calcium chloride which result in small beads. The isolate was isolated and characterized based on morphological characters and have been proved by pathogenicity tests. Based on the results dual culture test showed the highest percentage inhibition of radial growth which was 85.07% with 10 replication of Bipolaris oryzae. The findings from this study can be used as an alternative method to control brown spot disease which will render easier application to rice plantation in the future which suit for commercial purposes and contamination-free environment.