Use of locally available agri wastes as substrate for mass production of trichoderma harzanium

    05-Sep-2022
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Pranab Dutta and BC Das
Biocontrol offers safe, cheap and environmental friendly management of plant diseases and avoids or minimizes the usage of harmful fungicides. In biocontrol of plant diseases fungal antagonist like Trichoderma spp. Are extensively uses for control of several soil borne diseases and have also additional advantage of growth promoting effect. Many commercial formulations in solid form based on these antagonists have been developed worldwide.
Trichoderma is a genus of asexually reproducing fungi present in nearly all temperate and tropical soils. The genus is a strong saprophytic, fast grower, prolific producers of spore and powerful antibiotic producers. These properties make these fungi ecologically varied diversity and can be used to produce a wide range of product of commercial and ecological interest. Trichoderma has become a model biocontrol agent in the management of plant Disease as apart of IDM because of following characters:
· Produces high yield and high quality conidial biomass.
· Possess rhizosphere competence.
· Ability to thrive over a wide range of stress condition.
· Having mycoparasitic ability against large number of soil borne pathogens.
· Stimulate plant resistance and defence mechanism.
· Compatible with large numbers of pest.
· Easy to mass multiply.
· The final product has shelf life more than 6 months.
MODE OF ACTION
· Mycoparasitism through production of enzymes and coiling.
· Antibiosis through production of antibiotics.
· Competition for food ad space.
SELECTION OF TRICHODERMA STRAIN
During last 19 years we have search for a suitable biocontrol agent to be used as seed treating and soil treating agent we successes in identifying a strain of T. harzianum (DPP-105). With this a formulation “Biogaurd” has been formulated to fulfil the demand of farmers.
The different process involved in the production of “Biogaurd” are
· Inoculam production
· Selection of culture medium
· Growth and mass multiplication
· Harvesting and drying
· Scaling up and
· Formulations
Three methods viz. solid fermentation, liquid fermentation and deep tank fermentation technology are followed for multiplication of Trichoderma. Out of these solid fermentation is easy, popular and widely used by the farmers.
SOLID FERMENTATION PROCESS
Improved selective medias have been developed for cultivation of Trichoderma spp. Solid media are prepared comprising easily available organics such as wheat bran, saw dust, grain bran, wheat straw, rice straw, sorghum grain, banana leaves, banana peeled skin, farmyard manure (FYM). Presently, FYM and wheat bran-saw dust is extensively used to produce biocontrol agent of T. harzainum and T. viride. Well decomposed powdered FYM mixed with 1% peptone and half parts water are autoclaved at 30 lbs pressure for 1 hour intermittently for 2 times and heaped in a clean shady place. The stock culture of Trichoderma spp. Multiplied on potato dextrose agar (PDA) medium for 15 days inoculated under aseptic conditions, 500 ml of homogenous spore suspension prepared in a mixer is used for 10 kg of FYM. Heaps are then covered with polythene sheets (to prevent loss of moisture) for 30 days. Heaps are mixed thoroughly at an interval of 7 days. After 30 days of incubation this preparation is ready for application.
LIQUID FERMENTATION
This process involves production of large number of conidia mainly intended for seed treatment, soil application and foliar spray. The Trichoderma based liquid bioformulation developed at AAU i.e., Org-Trichojal with having shelf life of 16 months has found to be highly effective in farmers field for management of plant pathogens and enhance plant growth parameter and plant defence metabolite. The product has been commercialized through private entrepreneur.
DEEP TANK LIQUID FERMENTATION TECHNOLOGY
This involves mass production of fungus. In this technique Trichoderma spp. Are mass cultured in commercially available inexpensive ingredients (molasses and brewer’s yeast). The rapid mass production of antagonists for seed treatment formulation, the deep tank liquid fermentation mostly used.
GROWTH AND MASS MULTIPLICATION:
The fermenter medium used to grow and mass multiply Trichoderma spp. Consists of Molasses (30 kg) + Brewers yeast (5 g) + 1 litre water (fermenter medium of above concentrations is used. Procedure for mass production of Trichoderma spp. Is given below:
Autoclave both starter and fermented medium for 1 hour
Inoculate starter medium with efficient strain of Trichoderma and shake on rotary shaker
Inoculate fermented media with starter inoculam and supply regularly at for 10-15 days by shaking/bubbling
Filter through cotton muslin using funnel
Air dry or freeze dry the mat for 3 days find grind into powder this contain mycelium and chlamydospores
Powder is diluted with different diluents and used as dusts, granules, pellets, wettable powders, emulsifiable concentration
Produce is viable for 6 months, if stored at 50C and 3 months if stored at 200C
Maximum biomass is obtained generally after 15 days of inoculation.
FORMULATIONS
Different formulations are available and prepared for the usage as given below.
1. Powder formulation: It is done by mixing fermenter biomass with talcum powder as carrier.
2. Encapsulation in organic polymer like sodium alginate.
3. Pelleting biomass and bran with sodium alginate.
(To be contd)