Production ofTop White', 'Peterstar Pink', lilo Red', and 'Red Success' poinsettias were evaluated ina treatment combinations that included 10 compost blends, three compost levels, and two commercial soilless substrates of Sun shine Mix 1 and Pro Gro 300S as controls. The compost feedstocks included PSG polymer dewatered biosolids (PSG), lime dewatered biosolids (CP), yard trimmings(YT), poultry litter(PL),and municipal solidwaste(MSWBedmininster). The PSG, PL, YT, and MSW were co-blended with CP on a2:1 ratio (v/v), all other composts were co-blended on a1:1 ratio (v/v). The compost levels of33%, 50%, and 67% were mixed with peat perlite (1:1, v/v). There were five replicates per treatment. Plants were fertilized once weekly with 200 mg«L_1 Nfrom 21N2.2HP-16.6K. Sunshine mix produced control plants that had greater canopy diameter and plant grade than Pro Gro mix. Plant height was reduced as compost level increased from 33%to67%. Blends ofPSG:PL atthe33% and 50% levels and PSG:YT atthe 33% level produced premium-quality plants. Good-quality plants, similar to those grown in Sunshine Mix, were produced with the PSG or PL compost blended with immature MSW at the 33% level; PSG:PL blend at a 67% level; PSG:YT blend atthe 50% and 67% levels; and PLYT blend atthe 33% level.
Source: • HortScience Program Abstract Volume 32,#3
Keywords: Poinsettias PSG polymer Compost blend