A Detailed Guide to Using Trichoderma harzianum and Its Effects

Trichoderma harzianum can be diluted with water and sprayed according to the dosage instructions. The best time to use it is during the seedbed stage: apply once after sowing, then apply half the amount again at transplanting, and after that top up with half the amount of the fungal preparation every 3 months. For short seedling-raising periods, one application is enough.

I. Mechanism of Action

1. Competition: Trichoderma harzianum T-22 can grow rapidly around plant roots and leaves, seizing the sites on the plant surface and forming a protective shield, just like putting boots on the plant. This prevents pathogenic fungi from coming into contact with the plant root system and leaf surface, thereby protecting the plant roots and leaves from infection by the above pathogens and ensuring that the plant can grow healthily.

2. Mycoparasitism: Mycoparasitism refers to a complex process of a series of continuous steps: recognition, contact, coiling, penetration, and parasitism of the pathogen. During the interaction between Trichoderma and the pathogen, the host hyphae secrete certain substances that cause Trichoderma to grow toward the host fungus. Once the host is recognized by the Trichoderma parasite, a parasitic relationship is established. After Trichoderma recognizes the host fungus, the Trichoderma hyphae grow parallel along the host hyphae and coil around them in a spiral, producing appressorium-like branches that attach to the host hyphae. By secreting extracellular enzymes, it dissolves the cell wall, penetrates the host hyphae, absorbs nutrients, and thereby kills the pathogen.

3. Antibiotic effect: Trichoderma harzianum can secrete certain antibiotics, which can inhibit the growth and colonization of pathogens and reduce the harm caused by pathogens.

4. Plant growth regulation: Trichoderma colonizes the plant root system and produces compounds that stimulate plant growth and induce plant defense responses, improving the root microenvironment, enhancing plant vigor and disease resistance, and increasing crop yield and returns.

II. Dosage

Seedbed drenching: use 2-4 g of the product per sq m and drench the seedbed.

Root dipping: dilute with water at 20-80 times, then dip the roots or bulbs.

Soil mixing for pots and seedbeds: use 110-220 g per cubic meter. First prepare a mother solution according to the amount of water used, then mix evenly.

Root irrigation: dilute with water at 1500-3000 times, and pour 200 ml per plant. The dosage can be adjusted appropriately according to the size of the plant.

Flood irrigation after spraying: use 100-200 g per mu. Dilute with water at 300 times, spray, then flood-irrigate. The amount of water should be enough to soak down to the roots.

Seed treatment: use 60-125 g of the product per 50 kg of seeds. First mix half of the seeds with the product evenly, then add the remaining seeds and product and stir until evenly mixed. When treating seeds, an appropriate amount of water can be added to make stirring and mixing easier.