I am continuing after a gap on health management. I have discussed with you about plant health management principles among these Biological control is very important. Trichoderma is one of the important biological control agent that is better known as plant health manager. In my coming posts I would like to discuss about the mechanisms of the plant health management that are dealt with by Trichoderma.
Trichoderma species are free-living fungi that are common in soil and root ecosystems throughout the world. They are highly interactive in root, soil and foliar environment. They are presently in nearly all types of soils and other natural habitats especially those containing high organic matter. This fungus is a secondary colonizer and is frequently isolated from well decomposed organic matter. Trichoderma species have also been isolated from root surfaces of various plants, from decaying barks and from sclerotia and propagules of other fungi. In general the members of Trichoderma exhibit a preference for wet soils. While species like T. viride and T. polysporum are generally found in areas with low temperature, T. harzianum most commonly occurs in warm climatic regions. T. hamatum and T. koningii have been reported to occur in diverse climatic conditions. The presence of carbon dioxide has been reported to favour growth of Trichoderma. Trichoderma species have the ability to utilize a wide range of compounds as sole carbon and nitrogen sources and can utilize monosaccharides, disaccharides, polysaccharides etc. for carbon with ammonia being the most preferred source of nitrogen. The members of Trichoderma are generally considered to be aggressive competitors although this trait has also been found to be species dependent.
Trichoderma spp. are highly efficient producer of many extra cellular enzymes like cellulases, chitinases, glucanases, proteases etc. They are being exploited in variety of ways like source of cellulases (used in foods and textiles and also in poultry feed) and chitinases (generating disease resistant transgenic), in plant disease control (through their anti-fungal and anti-nematode activity and in plant defense induction), improvement of plant growth, straw/compost decomposition and suppression of some of the weeds.
All these properties can be described in my coming posts under different subheadings
B. Metabolism of germination stimulants
C. Trichoderma as an antagonist of nematodes
D. TRICHODERMA AS A BIOFERTILIZERS & PLANT GROWTH PROMOTER
E. TRICHODERMA AS A SYMBIONT AND DEFENSE INDUCER
F. TRICHODERMA AS A COMPOST COLONIZER