Characterization and antagonistic potentials of selected rhizosphere Trichoderma species against some Fusarium species.

Trichoderma fungi have been proved as efficient bioagents with great antifungal properties while many species in the plant's rhizospheres have been characterized as plant growth-promoting agents. However, many rhizosphere Trichoderma are yet to be fully explored for plant disease management. In this study, Trichoderma species were isolated from the rhizosphere of maize, banana, and cassava, and their biocontrol potentials were screened against some Fusarium species from oak leaves (F2B and F3) and laboratory cultures (Fus 296 and Fus 294). The isolated rhizosphere Trichoderma were identified as Trichoderma virens 1 (TCIV), T. virens 2 (TCVII), T. virens 3 (TMSI), T. hazianum strain 1 (TCVI), T. harzianum strain 2 (TCVIII), T. erinaceum (TMZI), and T. koningiopsis (TMZII). The dual culture experiment recorded the highest percentage inhibition in TMZII against OakF2B (31.17%), TCVIII against Fus 294 (45.18%), TMZI against Fus 296 (47.37%), while TCIV was most effective against Oak F3 (44.15%). Among the Trichoderma culture filtrates evaluated, TCIV showed the highest percentage inhibition against Oak F3 (52.39%), Oak F2B (48.54%), Fus 294 (46.65%), and Fus 296 (44.48%). All the Trichoderma isolates demonstrated expressed varying levels of antagonism against the Fusarium pathogens in vitro.

Plant Disease Management: Leveraging on the Plant-Microbe-Soil Interface in the Biorational Use of Organic Amendments.

Agriculture is faced with many challenges including loss of biodiversity, chemical contamination of soils, and plant pests and diseases, all of which can directly compromise plant productivity and health. In addition, inadequate agricultural practices which characterize conventional farming play a contributory role in the disruption of the plant-microbe and soil-plant interactions. This review discusses the role of organic amendments in the restoration of soil health and plant disease management. While the use of organic amendments in agriculture is not new, there is a lack of knowledge regarding its safe and proper deployment. Hence, a biorational approach of organic amendment use to achieve sustainable agricultural practices entails the deployment of botanicals, microbial pesticides, and organic minerals as organic amendments for attaining plant fitness and disease suppression. Here, the focus is on the rhizosphere microbial communities. The role of organic amendments in stimulating beneficial microbe quorum formation related to the host-plant-pathogen interactions, and its role in facilitating induced systemic resistance and systemic-acquired resistance against diseases was evaluated. Organic amendments serve as soil conditioners, and their mechanism of action needs to be further elaborated to ensure food safety.