Abstract

                                The initial populations of Trichoderma spp. in black, red and laterite soils were 5.2, 3.6 and 4.8 X103 cfu / g of soil. The soil from rhizosphere of French bean was collected and the population of Trichoderma was assessed by dilution plating technique using TSM. The population was estimated at 15, 30 and 45 days after sowing. At 15th day the population of Trichoderma isolates were maximum in P+ Z5TH8(Trichoderma harzianum)+Z7TV5(Trichoderma viridae) + Z10TVS10(Trichoderma virens) treatment (26 x103cfu/g of soil) which was followed by P+Z5TH8 treatment (23.33 x103 cfu / g of soil) and Z5TH8 (23.0 x103 cfu/g of soil) treatment. Lowest population was observed in natural soil (9.67 x103 cfu / g of soil). The populations of Trichoderma isolates differed significantly from the control.

Key words : Trichoderma, rhizosphere, population, french bean.