~ 511 ~  Journal of Pharmacognosy and Phytochemistry 2017; SP1: 511-512 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2017; SP1: 511-512 Amarendra Kumar Department of Plant Pathology, Bihar Agricultural University, Sabour, Bihar, India CS Azad Department of Plant Pathology, Bihar Agricultural University, Sabour, Bihar, India Rakesh Kumar Department of Soil Science and Agricultural Chemistry, Bihar Agricultural University, Sabour, Bihar, India Mir Imran ICAR-Indian Institute of Rice Research, Hyderabad, Telangana, India Correspondence Amarendra Kumar Department of Plant Pathology, Bihar Agricultural University, Sabour, Bihar, India Trichoderma: A potential biocontrol agent for plant disease management Amarendra Kumar, CS Azad, Rakesh Kumar and Mir Imran Abstract Trichoderma species are one of the most common soil fungi, isolated from various habitats, Most of the Trichoderma strains are mesophilic and grow well in a wide range of temperature from 15-35°C. Low temperatures in winter may cause a problem during biological control by influencing the activity of the Trichoderma. Trichoderma species are best friends of higher plants. They not only protect them by killing or antagonizing their enemies but also improve their overall health including toning up of their ability to tolerate diseases and pests. They act as symbiont and may colonize epidermal and cortical cells. Keywords: Trichoderma, Biocontrol, Plant, Disease, Management 1. Introduction Trichoderma is known for secreting secondary metabolites in the environment which affects on wide spectrum of various fungal groups, especially pathogenic fungi. More than two hundred years ago, when it was first described by Persoon in 1794, mycologists mistook Trichoderma Pers.: Fr. for a gasteromycetes. The true nature of this fungus was realized only half a century later. Although, Trichoderma has not yet given us any “wonder drugs” like penicillin, but the ability of some species to produce enzymes and/or attack or inhibit other fungi causing diseases in plants has attracted major research efforts in several areas specially biological control of plant diseases. About 35 species of Trichoderma are currently recognized on the basis of morphological and molecular data. However, T. harzianum, T. virens and T. viride are the three most cited species of Trichoderma for biological control of plant diseases. Weindling in 1932 [13] , for the first time implicated the role of Trichoderma lignorum in the biological control of citrus seedling disease caused by Rhizoctonia solani. Since this pioneering work, several reports on successful biocontrol by Trichoderma spp. have accumulated. T. harzianum, T. viride and T. virens are the most widely used for biological control. They are reported effective in controlling root rots /wilt complexes and foliar diseases in several crops and are reported to inhibit a number of soil borne fungi like Rhizoctonia, Pythium, Sclerotinia, Sclerotium, Fusarium spp., Macrophomina etc. and recently root knot nematode, Meloidogyne spp. Trichoderma cannot tolerate dry conditions; however, we may need these agents against plant pathogenic fungi which are able to grow and cause disease even in dry soils. The pH characteristics of the soil are also considered to the most important parameters affecting the activities of mycoparasitic Trichoderma strains. Trichoderma strains were able to grow in a wide range of pH from 2.0 – 6.0 with an optimum at 4.0. Mycoparasitic Trichoderma strains were found to be able to display various enzyme activities under a wider range of pH values 3.0- 6.0.Trichoderma are more effective in acidic soil, however Pseudomonas fluorescence are more effective in slightly alkaline soil (above pH 6.5). One of the most interesting aspects of studies on Trichoderma is the varied mechanisms employed by Trichoderma species to affect disease control. In addition to being parasite of other fungi recent studies shows that they are opportunistic plant symbionts. They produce or release a variety of compounds that induce localized or systemic resistance responses. Biocontrol activity of Trichoderma is due to combination of its ability to serve as antagonist, plant growth promoter, plant defense inducer, rhizosphere colonizer and neutralizer of pathogen’s activity favouring infection. Mycoparasitism is a complex process involving tropic growth of the biocontrol agent towards the target organism, coiling and finally dissolution of the target organism’s cell wall/cell membrane by the activity of enzymes. (Rather than coiling, hyphae of Trichoderma may grow attached with hyphae of R. solani, form haustoria, which may penetrate host fungal cell to draw nutrients. Same isolate of Trichoderma harzianum, against R. solani, may show both coiling and haustoria formation, however, one or other mechanism may dominate depending upon isolate of the antagonist.