THE EFFECTS OF ADDITION OF TRICHODERMA INOCULA ON FLOWERING AND SHOOTGROWTH OF BEDDING PLANTS

Trichoderma isolates were added to a range of peat-based growing media as a dried fermenter biomass to study the prospects of general use in promoting bedding plant growth. The responses of marigold plants in p eat/grit compost, petunia plants in peat/sand compost and verbena plan ts in Fisons M2 compost to inoculation with a range of Trichoderma str ains applied as dry fermenter biomass were studied. In tests with mari gold seedlings, T. harzianum strains WT, T35 and 20 and T. viride stra in 47 applied at a rate of 1% w/v showed increases in shoot fresh and dry weights of up to 40% and 52%, respectively, and T. harzianum strai ns T35 and 20 increased the number of flowers by up to 40%. In tests w ith petunia plants, T. harzianum strain TH1 applied at a rate of 0.1% w/v increased the shoot fresh weight by 82% and dry weight by 87%. The number of flowers and buds were increased with strain TH1 at applicat ion rates of 0.1% and 0.01% w/v and with T. harzianum strain T12B appl ied at a rate of 0.1% w/v by up to 227%. In tests with verbena seedlin gs, T. harzianum strains WT and 20 and T. viride strains 75, 92 and T8 were applied at 0.3, 0.7 and 1.0% w/v. Depending on concentration, ea ch strain was able to increase either number of flowers, weight of flo wers, shoot fresh weight or shoot dry weight, but only WT applied at 1 % w/v increased all these parameters. Thus Trichoderma biomass can inc rease flowering and shoot growth of petunia, marigold and verbena unde r a range of cultural conditions.