Plant diseases caused by harmful fungi, bacteria and pests often reduce crop yield and farmers have been using conventional chemical pesticides to tackle such issues. But overuse of these chemicals has led to soil damage and environmental pollution. Hence, it’s a big time to use Biological control as the solution for this problem. It involves the use of living organisms, such as Trichoderma harzianum, to protect plants. Let’s dive into the knowledge of this Biofungicide which is harmless for the environment.

What is Trichoderma Harzianum?

It is a fungal species that is commonly found in soil, on root surfaces and on decomposed plant material. It works against harmful fungi and promotes healthy plant growth. This fungus belongs to the genus Trichoderma which includes several species with similar beneficial properties. Among them, T. harzianum is the most widely studied and commercially used fungus.

How does Trichoderma harzianum work?

Trichoderma harzianum works through several mechanisms, including competition, mycoparasitism and antibiosis, which help to suppress plant pathogens. Trichoderma can induce plant defense mechanisms, which leads to improved resistance against diseases.

Let’s know it better.

Competition

The growth rate of Trichoderma harzianum is much faster than the other plant pathogenic fungi, due to which it can easily inhibit the growth of other fungi pathogens. It colonizes the rhizosphere (the soil region around plant roots) and competes with pathogenic fungi for space and nutrients. This competition limits the growth and establishment of pathogens and reduces their ability to cause disease.

Mycoparasitism

It is an important mechanism of T. harzianum as it can parasitize many genera including Pythium, Rhizoctonia, Phytophthora, and Peronospora. It directly affects the mycelium and causes the pathogen cells to swell, change shape, become shorter and round, shrinking the inner contents and breaking the cell wall. Furthermore, it completely covers the mycelium of pathogenic fungi, which leads to their death and ultimately protects the crop.

Antibiosis

1. harzianum produces some antagonistic substances that suppress the growth of plant pathogenic fungi. It releases hundreds of antimicrobial secondary metabolites, including Trichomycin, Gelatinomycin, Chlorotrichomycin, and antibacterial peptides. These secondary metabolites can kill harmful bacteria and help plants grow better, and serve as useful ingredients for making natural agricultural antibiotics.

Induced systemic resistance by Trichoderma

When a plant is exposed to Trichoderma, it becomes more resistant to future attacks from pathogens. It induces resistance to all parts of the plant that were directly exposed, as well as throughout the entire plant system. Trichoderma triggers defense mechanisms in plants, leading to changes at physiological, biochemical, and molecular levels.

How to use it in Farming

1. harzianum is available in powder form. Its dosage can depend on the Colony Forming Unit (CFU) of the product. The more the active spores, the less will be the dosage. It should be used in the early morning or late in the evening for efficient control of diseases. High humidity and cloudy weather favour the T. harzianum spread. Exposure to sunlight may degrade its viable cells and lead to low efficacy.

Seed Treatment

For the Trichoderma with CFU 2 x 106 CFU/gm, take 10 grams of T. harzianum in 50 ml of water and apply it on 1 kg of seed uniformly and shade dry the seeds for 20 to 30 minutes before sowing. It will protect the seeds from soil borne fungal diseases and help in quick germination.

Nursery treatment

Take 50 grams of T. harzianum and mix it with 10 liters of water and drench the soil with the solution. It will make the seeds germinate fast and will eliminate the risk of fungal diseases.

Seedling treatment

Dissolve 100 grams of Trichoderma harzianum in 10 liters of water and dip the roots of seedlings in the solution for 30-45 min before transplanting. It helps in better development of roots and improves nutrient uptake leading to a healthy plant growth.

Soil application

Mix 2.5 kg of T. harzianum with 50 kg farmyard manure and broadcast the mixture in one hectare before sowing. This will increase the soil fertility and enhance the ability to fight with fungal diseases.

Benefits of Using Trichoderma Harzianum

When  crops face challenges from salinity, drought or high temperatures, Trichoderma helps them stand strong. It improves photosynthesis, reduces oxidative stress and activates antioxidant enzymes, which helps plants stay healthy even under hazardous environmental conditions. With Trichoderma at the forefront, the vision of a greener chemical free future becomes achievable.

• Controls most of the soil borne fungal diseases in the field.
• Improves the seed germination and root development.
• Improves the nutrient uptake.
• Boosts plants immunity to fight with the upcoming disease risk.
• It is compatible with organic fertilizers and organic farming practices.
• Safe for humans, animals, beneficial insects and the environment.
• It reduces dependency on chemical fertilizers.

Target diseases control

It controls several soil-borne diseases in vegetables and other transplanted crops. Some of the diseases it targets are:

• Damping off caused due to Pythium species which might kill all the seedlings.
• Wilt disease which is caused by the Fusarium species and affects crops like tomato, cotton, banana etc.
• Collar rot which is caused by Sclerotium rolfsii in crops like groundnut and sunflower.
• Root rot which is caused by Rhizoctonia solani in crops like chilli, brinjal and pulses. 
• Seed rot is caused by various fungi in different crops, it mostly affects cereals and vegetable crops.

Conclusion

Trichoderma harzianum is a powerful and eco-friendly solution for managing plant diseases and promoting healthier crop growth. Its unique mechanisms of Competition, Mycoparasitism, Antibiosis and Induced Systemic Resistance makes it highly effective in controlling a wide range of soil-borne fungal pathogens. It supports soil health, boosts plant immunity and fits well with organic farming practices. With various application methods like seed treatment, nursery treatment, seedling dip and soil application, it can be used across diverse crops and conditions. Its regular use not only reduces the dependency on harmful chemicals but also ensures long-term sustainability in agriculture. As a natural protector of plants, Trichoderma harzianum plays a crucial role in integrated disease management and is a key input for achieving higher yields in an environmentally responsible way. Adopting such Biological solutions is not just a practice, it is a step towards a safer, greener and more productive future in farming.