Effect of pesticides on Trichoderma harzianum

In this paper, for improving the integrative controlling effect of Trichoderma harzianum, effect of 14 pesticides on T. harzianum was studied with growth rate method and the circle of inhibiting bacterium method. The results suggested that all 14 tested pesticides with different concentration showed different controlling effect on mycelia growth of T. harzianum. At the recommended concentration in fields, 56% 4-chloro-O-tolyloxyacetic acid and sodium salt SP, 10.8% quizalofop-p-ethyl EC, 720g/L metolachlor EC,48% acetochlor and atrazine EW,10% difenoconazole WG showed higher inhibition rate with over 90% on mycelia growth of T. harzianum, and streptomycin showed lower inhibition rate with 18.75%. Virulence regression equation, EC₅₀ and correlation coefficient of all 14 pesticides were calculated by use of growth rate mehod. Through comparing the circle of inhibiting bacterium, only inhibiting action of 10% difenoconazole WG was obvious with diameter 2.60cm.