Yard Trimmings–Biosolids Co-compost can Substitute for Sphagnum Peatmoss in Tomato (Lycopersicon esculentum Mill.) Transplant Media

Abstract

Large volumes of a compost made by mixing and co-composting yard trimmings (YT) and biosolids (BS) feedstocks have recently become available to the Florida vegetable industry. Compost used as vegetable transplant medium may be less expensive than traditional Sphagnum peatmoss, which is a non-renewable resource. `Agriset 761' tomato seed were planted in five combinations of compost, peat, and vermiculite media: 0:70:30 (control), 18:52:30, 35:35:30, 52:18:30, and 70:0:30 by weight, respectively. The presence of compost in the media increased leaf area, shoot dry weight, and number of leaves 21 days after treatment (DAT), and leaf area, shoot dry weight, root dry weight 28 DAT compared with the control. There were no differences in root dry weight 21 DAT and number of leaves 28 DAT between treatments containing compost and the control. Plants in the compost treatments had greater final leaf area, shoot dry weight, root dry weight, and stem diameter but less chlorophyll content compared with the control. There was no effect of compost rate on any of the response variables measured. Neither final leaf number nor stem length were affected by media composition. The results suggest that YT/BS co-compost can be used as an alternative to peat media for tomato transplant production, and that the rate of use is not critical.