Disease-causing bacteria in the soil are exceedingly challenging to combat. Although several approaches, including crop rotation, the use of disease-resistant plant varieties, and the application of pesticides, are tested in the management of this particular pathogen, they are insufficient. The use of chemicals, in particular, leaves behind residues in the products and soil that have negative effects on people and other living things, lead to the emergence of pathogens that are resistant to the drugs used, and cause some fungi’s mycelium and spores to persist for many years in the soil despite the use of chemicals, among other things. Detrimental elements exist1.
An ecologically acceptable ecological solution to the issues produced by conventional chemical methods used to protect plants is biological control, which is defined as the employment of certain microorganisms to battle plant infections and plant pests. All commercial solutions for the biological control of plant diseases are based on the effective application of a few bacterial species and more than ten species of fungus that may thrive in the rhizosphere2.
Against pathogens that wreak illness on plants, Trichoderma spp. is effective. As a result of their colonization of the plant’s root surface, research in the literature claim that they alter various aspects of plant metabolism3. In addition to settling in the roots of plants, they aid in the development of plants by creating metabolites that resemble hormones, making nutrients from the soil and organic matter available to the plant, inhibiting the development of pathogens in the plant, and avoiding the onset of illness4. The Trichoderma species are the most extensively investigated fungus in the realm of biocontrol, and they are useful in biocontrol through processes such mycoparasitism, antibiosis, and competitiveness. Additionally, through promoting plant development, several Trichoderma species aid in raising crop yields. Additionally, it has been noted that the Trichoderma species used have the effect of enhancing plant disease resistance. In various research published in the literature, T. harzianum T22 and T. atroviride P1 isolates on lettuce growth in the greenhouse; In field circumstances, the impacts on tomatoes and peppers were explored. According to reports, T. harzianum increases tomato and pepper output in places where it is used, as well as the plant’s height, number of leaves, and number of fruits it produces, all of which are 300% more than in the control group5. Trichoderma metabolites are recognized to have a favorable impact on plant growth. According to reports, Trichoderma produces secondary metabolites that function in plants as auxin-like substances and can exhibit their best behaviors at extremely low concentrations4. However, Trichoderma species create gluconic acid, which, together with manganese and other elements, lowers the pH of the soil and aids in plant metabolism. It is well known that minerals and trace elements affect how cations and phosphate dissolve. According to reports, Trichoderma’s activity is increased by the organic substrates utilized5.
In a research by, it was shown that the application of Trichoderma harzianum (ITCC-457) and Rhizobium bacteria improved the development of peanuts and decreased the root rot brought on by Sclerotium rolfsii6. Trichoderma harzianum T1 was isolated from the soils of Central Anatolia Region, and evaluated its resistance to various concentrations of Cu+2, Zn+2, Mn+2, Fe+2, and Ca+2. They found that the isolate is tolerant to Fe+2 and low tolerance in the environment containing Ca+2. Researchers have discovered that MnO2 and metallic zinc may be dissolved by T1 isolate in a liquid media. Competitiveness against pathogens, antibiosis, mycoparasitism, hypal contacts, and enzyme release is only a few of the various strategies antagonistic microorganisms like Trichoderma exploit7.
References:
- Cook RJ, Baker KF. The nature and practice of biological control of plant pathogens. Nat Pract Biol Control plant Pathog. Published online 1983.
- Viterbo A, Ramot O, Chernin L, Chet I. Significance of lytic enzymes from Trichoderma spp. in the biocontrol of fungal plant pathogens. Antonie Van Leeuwenhoek. 2002;81(1-4):549-556. doi:10.1023/A:1020553421740
- Howell CR. Mechanisms Employed by Trichoderma Species in the Biological Control of Plant Diseases: The History and Evolution of Current Concepts. https://doi.org/101094/PDIS20038714. 2007;87(1):4-10. doi:10.1094/PDIS.2003.87.1.4
- Kleifeld O, Chet I. Trichoderma harzianum-interaction with plants and effect on growth response. Plant Soil. 1992;144(2):267-272. doi:10.1007/BF00012884/METRICS
- Küçük ve Güler. Bitki Gelişimini Teşvik Eden Bazı Biyokontrol Mikroorganizmalar.
- Ganesan S, Sekar R. 7 Screening of Biocontrol Agents Against Rhizoctonia solani Causing Web Blight Disease of Groundnut (Arachis hypogaea L.). Accessed February 3, 2023. www.intechopen.com
- Ranasingh N. SA and NM. Use of Trichoderma in Disease Management.
Figure References:
- https://gardenerspath.com/how-to/organic/trichoderma/
- https://biocontrol.entomology.cornell.edu/pathogens/trichoderma.php
Inspector: Meryem Melisa KAR
