Efficacy of Two Methods 'Seed Coating' and 'Soil Application' of Trichoderma on Growth Parameters of Tomato Plant

Trichoderma spp. are free living fungi which mostly are considered as biocontrol agents of plant pathogenic fungi. Some isolates of this fungus also have an effect on plants growth promotion and regulation. The this research, evaluated the effect of ten Trichoderma isolates including Trichoderma harzianum (T.BI, T.7, T.16, T.16A, T.20), T.virens (T.6, T.21, T.65), T.koningi T.77 and Trichoderma sp. T.14N were tested on tomato growth parameters by two methods of seed coating and soil application. These experiments carried out in a factorial arrangement based on completely randomized design with five replications. The treatments were included two factors: ''isolates'' in 11 levels and ''inoculation method'' in 2 levels. Inoculants of Trichoderma isolates were averagely applied at a ratio of 107 propagle per gram of soil and 5×106 spore on seed surface for soil application and seed coating methods, respectively. Two months after the sowing the seeds, the dry weight of shoots and roots were measured. The results showed the significant difference between the effect of Trichoderma isolates and inoculation method as well as their interactions (P≤0.05). Based on the results of this study, The T20 isolate increased 58.68% and 61.93% in roots and shoots dry weight compared to control in soil application method, respectively. Soil application method has showed better performance of Trichoderma isolates on plant growth compared to seed coating method. Results of this study implied that Trichoderma isolate type and inoculation method have significant effect on tomato growth parameters.