**4. Formulations and application**

The formulation depends on the type of application, its combination of active ingredients, such as fungal spores with the inert material as diluents of the desirable form. The formulation developed through standard air dried mats and mixed with the carrier contain 108 –109 propagules per gram [80]. *Trichoderma* is grown in the liquid medium is mixed with talc powder in the ratio of 1: 2 and dried to 8% moisture under shade. Bio-control formulation, distribution and execlution of microbial antagonists [81]. Talc based formulations of *Trichoderma viride* developed for seed treatment of pulse and rice crops [82]. The commercial formulations of *Trichoderma* spp. based on carriers are available for controlling plant diseases [83]. *Trichoderma* formulation prepared based on coffee husk which is a waste from the coffee curing industry [84]. *Trichoderma* was formulated on press mud to farmers and value-added organic manure by sugar factory [75]. Oil-based formulations are suitable for foliar sprays under dry weather conditions with prolonged shelf life. *T. harzianum* is an emulsion based formulation with a shelf life of 8 months use for the control of post -harvest decay of apple caused by *Botrytis cinerea* [37]. The application of *Trichoderma* is very important for successful diseases management. Das et al. [24] tested three different

media amended with and without osmoticant (Mnaitol) viz., potato dextrose broth (PDB), modified Richard's broth (MRB) and Czapek dox broth (CDB) were tested for biomass production of *Trichoderma harzianum*. Osmoticant amended MRB was found best for production of maximum sporulation, cfu and dry weight of biomass of the antagonist.

The common methods are seed treatment, seed bio-priming, seedling root dip, and soil application and wound dressing.

## **4.1 Seed treatment**

Seed coating with dry powder of *Trichoderma* just before sowing is an effective method of antagonist for the management of soil-borne diseases. Seeds coated with a commercial dry powder of *Trichoderma* just before sowing at 3 to 10 g/kg seed based on seed size [85]. Seed treatment with talc-based and wheat bran based formulations use at 4 g/kg of seed have been recommended [74]. *Trichoderma* germinates on treated seed surface as they are sown in the soil; on germinating propagules colonize the seedlings roots and rhizosphere [86]. *Trichoderma harzianum, Trichoderma virens* and *Trichoderma viride* were found to be effective seed protectants against *Pythium* spp. and *Rhizoctonia solani* [87]. Seed treatments are effective against the sheath blight of rice [25], loose smut of wheat [88]. Das et al. [24] reported that seed treatment with osmoticant amended talc based bioformulation of *Trichoderma harzianum* was best in reduction per cent disease index of soybean rot caused by *Rhizoctonia solani*. Seed treatment with *Trichoderma harzianum* was found has most effective in improving seed germination (18.43%), reducing 90.46% infection by *Rhizoctonia solani* in soybean and increasing yield (69.51%) over control plot [89].

#### **4.2 Seed bio-priming**

Treated seeds with *Trichoderma* incubate until radical emergence is referred to as bio-primming. This technique is a simple coating of seeds and results in rapid and uniform seedling emergence and also reduces the amount of bio-control agents. *Trichoderma* conidia germinate on the seed surface and form a layer around seeds. Such seeds tolerate adverse conditions of the soil better than the non-primed seeds. Seed bio-priming was successfully used in tomato, brinjal, soybean and chickpea [90]. It results in rapid and uniform seedling emergence and reduces the amount of bio-control agents [91].

### **4.3 Seedling root dip treatment**

It is suitable for transplanting rice and vegetable crops. The seedlings can be treated with the spore suspension by mixing 10 g of *Trichoderma* powder with 100 g of well rotten FYM per liter of water and dipping roots for 10 minutes before transplanting/drenching in nursery beds. This method is generally used for vegetable crops, rice where transplanting is practiced [92]. Root dipping in antagonist's suspension reduces disease severity and enhances seedling growth in rice, tomato, brinjal, chili and capsicum as reported [92]. The reduction of sheath blight disease of rice by root dipping in spore suspension of seedlings before transplantation [93]. Root dipping of tomato seedlings reduces the severity of root- knot nematode (*Meloidogyne incognita*).

#### **4.4 Soil treatment**

Trichoderma is capable of colonizing on farmyard manure (FYM) and then applied to the soil is the most effective method for the management of soil-borne disease**s.** The application of bio-control agents to the soil before or at the time of planting for control of soil- borne fungal pathogens [94]. Soil application of *Trichoderma viride* alone and in combination reduced red rot caused by *Colletotrichum falcatum* [95] and seedling blight, stem rot, color rot and root rot disease of Jute [14, 96]. Soil treatment with 5 Kg of *Trichoderma* powder per hector mixed after turning of sun hemp/dhaincha into the soil for green manuring or 1 kg of *Trichoderma* formulation in 100 kg of FYM. Some species of *Trichoderma* are reported to cause green mold disease of mushrooms [97]. Soil application (2%) of *Trichoderma harzianum* enriched enriched farm yard manure showed excellent result in reduction of stem rot disease incidence caused by *Rhizoctonia solani* and collarot of disease of tomato caused by *Sclerotium rolfsii* with increased seed germination (%), plant growth parameters and yield of the crop [38, 98].

#### **4.5 Aerial spraying/wound dressing**

*Trichoderma* can reduce the severity of diseases under field conditions. *Trichoderma* has been successfully applied to the aerial plant parts and on wounds of shrubs and trees [18]. Suspension of *Trichoderma* has been successfully applied to the aerial plant parts infected with *Alternaria* leaf spot of *Vicia faba* [99]. *Trichoderma harzianum* and *Trichoderma* virens talc-based formulations use for foliar sprays that reduce disease incidence of sheath blight of rice [100, 101]. Affects the efficacy and survival of antagonist in phylloplane [102]. The dosage and application have to be standardized based on the crop value. Foliar spraying of consortial formulation of *Trichoderma harzianum* + two entomopathogeic fungi along with seed treatment, seedling root treatment showed significant reduction of three important diseases of brinjal viz., *Phomopsis* leaf blight and fruit rot, *Alternaria* leaf spot, and *Fusarium* wilt [103].
