Submitted to: Acta Horticulture Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 2011
Publication Date: N/A
Technical Abstract: Bioplastic materials are gaining increasing interest in a variety of different industrial and domestic applications. Beside its usage as mulching films and plant clips in horticulture, no other agricultural applications have been proposed. In 2009 we demonstrated that granules made of the bioplastic Mater-Bi® are an efficient and practical solution for field applications of a biocontrol isolates of the fungus Aspergillus flavus. Here, we investigated the feasibility to extend this approach for delivering propagules of two biocontrol Trichoderma isolates with the final objective to control damping-off and Pythium root rot of selected bedding, horticultural and turf grass species. Bioplastic granules entrapping conidia of Trichoderma virens Gv29-8 or T. harzianum ATCC 20847 were applied to a potting mix infested with the fungal pathogen Rhizoctonia solani. Both isolates showed a positive effect in reducing damping-off disease of impatiens and tomato seedlings. In the case of potting mix infested with the lowest level of pathogen propagules causing 30% of damping-off, application of 1% (w/w) of inoculated granules resulted in 5 and 3% of impatiens and tomato seedlings, respectively, affected by damping-off. With a more severe infestation (50% of damping-off), bioplastic granules produced an average of 80% suppression of damping-off in both species. Granules entrapping conidia of the biocontrol isolate ATCC 20847 were significantly more effective in protecting impatiens and tomato seedlings. The experiment was repeated with potting mix infested with Pythium ultimum and planted with annual bluegrass. Bioplastic granules inoculated with the T. harzianum isolate significantly reduced (~ 90%) the impact of Pythium root rot caused by this pathogen. Results from this study indicated that the usage of this bioplastic-based formulation is extendable for the biocontrol of damping-off and Pythium root rot in flori/horticulture crops and turf grass.