The Use of Compost as a Peat Substitute for Organic Vegetable Transplants Production

Two experiments were conducted to evaluate different compost mixtures as peat substitutes, and the effect of Trichoderma and mycorrhiza fungi application on transplants quality. Seeds of commercial lettuce (Lactim sativa L.) and cabbage (Brassica oleracea), a nonmycotrophic plant were sown in 'Speedling' trays. Plant growth response was determined in four weeks old seedlings (commercial transplanting age). Mineral content was analyzed in the shoot and in the growth media. In both species, seedlings' height, weight, and chlorophyll concentration were greater in compost-containing media as compared to the commercial peat-vermiculite medium. Lettuce seedlings from noninoculated media were higher and had greater weight, and chlorophyll conc than seedlings from mycorrhiza inoculated media. Cabbage seedlings from mycorrhiza and Trichoderma inoculated media were higher and had greater weight, and chlorophyll concentration than seedlings from noninoculated media. The results are discussed in relation to the effect of the media on macronutrient availability and in relation to the competitive/synergistic interactions among the fungi and the hosts.