**7. Trichoderma**

*Sustainable Crop Production*

was 100% in *Albizia amara, Peltophorum pterocarpum* and *Pongamia glabra, 80% in Derris scandens* 78% in *Erythrina variegata*, 18% in *Pterlobium* and16% in *Prosopis chilensis*. However, there is no VAM fungi infection in five plant species viz. *Albizia lebbeck, Bauhinia tomentosa, Cassia, Prosopis juliflora* and *Tamarindus indica* at Alagar Hills of Tamil Nadu, India. Similarly, AM Fungi colonized with several tree species semi-arid zone of South India, 1, 2 and 3 years old *Casuarina equisetifolia* [2], *Leucaena leucocephala* [66], *Feronia elephantum* with AM fungi (*Glomus fasciculatum*), *Samanea saman* [67]. Similarly, 16 different species of Arbuscular mycorrhizal fungi were isolated from rhizosphere of teak (*Tectona grandis*) among these *Glomus* and *Aculospora* found in dominant species and seedlings inoculated with combination of Arbuscular fungi had good quality seedlings and increased shoot height compared to with individual AM fungus in *Tectona grandis* [68].

*Leucaena leucocephala* seedlings were inoculated with different types of vesiculararbuscular mycorrhizal fungi found that the collar diameter increment of between 18 and 123% [66]. Similarly, *Pterocarpus indicus* inoculated with vesicular-arbuscular mycorrhizal fungi improve the shoot diameter [69], root collar diameter in sweet gum seedlings by 268% [70]. *Feronia elephantum* with AM fungi (*Glomus fasciculatum*) increase the plant growth especially root length and was recorded the root length increment was up to 84% [30]. Similarly shoot length was higher in *Samanea saman* [67] Mycorrhiza colonization also protect the roots from the soil pathogens [71]. AM fungi significantly increase the net photosynthesis by increasing total chlorophyll and carotenoid contents ultimately increasing carbohydrate accumulation. The chlorophyll content, fresh weight and leaf area are higher in mycorrhizal plants than in non-mycorrhizal plants but differences are significant only under draught stress conditions [72]. In mycorrhizal infected groundnut roots, high concentrations of ortho-hydroxy phenols were present. This type of phenols has been known to play an important role in plant disease resistance [73]. Inoculation of AM fungi is enhancing the plant quality by stimulating the synthesis of secondary metabolites which can be important for plant tolerance to abiotic and biotic stresses [74]. According to Morandi et al. [75] the Phenolic substances, such as phytotoxins are synthesized when the root is infected by a pathogen. They are non-specific toxic substances, which can be considered to play a role in disease resistance. Kapoor et al. [76]

observed a significant increase in the density of glandular trichomes in the medicinal plant *Artemisia annua* following inoculation with the AM fungi *G. macrocarpum* and

The chlorophyll a, chlorophyll b, total chlorophyll and Carotenoid contents increased in mycorrhizal seedlings compared with non-mycorrhizal tree seedlings of *Cassia siamea*, *Delonix regia*, *Erythrina variegata*, *Samanea saman* and *Sterculia foetida* [77]. A significant enhancement in biochemical parameters like total chlorophyll content, soluble protein and NRase activity in *Pongamia pinnata* seedling 10.7, 48.5 and 43.6% increase over control with the combined inoculation of Rhizobium, Phosphobacteria and AM fungi [78]. Similarly, an increase in chlorophyll content and soluble protein was observed in *Ziziphus mauritiana* when inoculated with AM fungi [79] and *Dalbergia sissoo* inoculated with Rhizobium and mycorrhizae [80] and in Shola species inoculated with Azospirillum + Phosphobacteria and AM fungi [22]. Eucalyptus seedlings inoculated with mixed *Glomus mosseae, Trichoderma viride* and *Glomus fasciculatum* increases the phosphorous content of shoot and root over control. Then increased rate of P uptake and inflow in roots is regarded as the major contribution of AM infection [81]. The AM colonization increased initially

*G. fasciculatum* contributing to enhance artemisinin content in the plants.

**6.3 Role of bio-inoculants on plant growth and metabolites**

**276**

up to 45 days but decreased thereafter [82].

The genus Trichoderma is the most common fungi found in all climatic condition. It can be isolated in all type of soil. It is also found in plant root, rotting wood, plant litter and seed. Fungi of the genus Trichoderma are important biocontrol agents (BCAs) of several soil borne phytopathogens. Trichoderma use different mechanisms for the control of phytopathogens which include mycoparasitism, competition for space and nutrients, secretion of antibiotics and fungal cell wall degrading enzymes. In addition, *Trichoderma* could have a stimulatory effect on plant growth 48 as a result of modification of soil conditions.

Shoot length and fresh weight were more in *Eucalyptus saligna* seedlings inoculated with *Trichoderma viride*. The greater height and fresh weight of *Acacia nilotica* inoculated with Trichoderma due to the Trichoderma species produce growth hormones which result in better growth of shoots. *Trichoderma* sp. co-inoculated with *Azotobacter* sp. and *Bacillus megaterium* showed a significant increase on the growth of Teak and Indian red wood under nursery condition [96]. The growth promoting substances are known to cause enhanced cell division and root development [97]. Similarly, many strains of Bacillus pseudomonas and Trichoderma have been implicated in improvement of overall growth of many crop plants [98].
