**3. Mass multiplication**

The mass production of *Trchoderma* for field application and commercial use. There are two methods of production as (i) Solid-state fermentation (ii) Liquid-state fermentation.

#### **3.1 Solid-state fermentation**

It is a common method for mass production of *Trichoderma*. The *Trichoderma* spp. have been widely grown on solid substrates like sorghum grain, wheat straw, wheat bran, spent tea leaf waste, coffee husk, rice husk, banana leaves, sawdust etc. and their mass multiplication [70–72]. The commonly used for mass culturing of *Trichoderma* spp. on the solid substrate as sorghum grain [73], wheat bran-saw dust [74] and other agro-based waste products. Cereal grains like, sorghum, millets, ragi are used as substrates [75]. The grains are moistened, sterilized and inoculated with *Trichoderma* and incubated for 10–15 days. The dark green spore coating on the grains of *Trichoderma* produces. These grains can be powdered and used as a seed treatment or grains may use as it is for enhancing FYM for soil application.

Wastage substrate potato peel, brinjal, spinach, sugarcane, banana, papaya, guava, tea leaves and pea husk used for the multiplication of *Trichoderma harzianum* and *Trichoderma viride. Trichoderma harzianum* multiplied on presoaked and autoclaved Jhangora seeds for 12 days at 28°C, air dried, ground and passed through 50 and 80 mesh sieves simultaneously to obtain the powder of spores [76]. The commercial formulation was prepared by diluting this powder with the talcum powder containing 1% carboxymethyl-cellulose to get the desired concentration of biocontrol agent.

### **3.2 Liquid fermentation**

*Trichoderma* is grown in a liquid fermentation system on media in stationary/ shaker/fermentor and used for field application. The production of *Trichoderma* in liquid state fermentation includes molasses and brewer's yeast [77], and Jaggery-soy medium [32, 33]. Viable propagules of *Trichoderma harzianum and Trichoderma viride* can be obtained within 96 h of fermentation in a fermentor with aeration, agitation, temperature controls [78]. Maximum biomass of Trichoderma spp. in short-time by using the appropriate medium in a fermentor with aeration, agitation, temperature, pH with antifoam controls than in shake-flask cultures and more suitable for industrial production. The liquid fermentation can be separated of biomass with medium and incorporated into dust, granules, pellets, wettable powders or emulsifiable liquids. The carrier is inert as the food base of *Trichoderma* spp. can be formulated as pellets [79], dust and powders [40, 41] and fluid drill gels [21]. Molasses yeast medium is used for mother culture; it's prepared by adding of molasses 30 g, yeast 5 g and distiller water 1000 ml. The medium hand out into conical flasks and sterilized at 15 lb. pressure for 15 minutes in an autoclave. After the cooled medium is inoculated with 10 days old fungal disc of *Trichoderma viride* and then incubated for 10 days for fungal growth, serves as a mother culture. The mother culture was added to the fermentor at the rate of 1.5 lit/50 lit of the medium and incubated at room temperature for 10 days. Then the incubated fungal culture is used for commercial formulation preparation using talc powder.
