Unblended or Co-blended Composts for Production of Potted Chrysanthemum

Abstract

Blending compost from various feedstocks may increase the beneficial effects of compost as potting substrate. A factorial treatment combinations included 10 compost combinations, Sunshine Mix and Pro Gro 300S as controls, three compost levels, and three chrysanthemum cultivars. The compost combinations were Compro (CP), poultry litter (PL), PSG polymer dewatered biosolids (PSG), yard trimmings (YT), CP:PL, CP:PSG, CP:YT, PL:PSG, PL:YT, and PSG:YT; all blends were on a 1:1 ratio (v/v). The compost levels were 50%, 75%, 100%; and chrysanthemum cultivars included `Boaldi', `Cherry Davis', and `Yellow Favor'. All treatments were replicated six times. Plants were fertilized with 100 mg/L N from 20N–8.8P–16.6K twice weekly. All compost substrates, except PSG blends produced plants that were shorter than the controls. All compost blends produced similar or greater number of flower than the controls. Plants grown in substrates containing PSG and/or CP produced dark green or green foliages, and other substrates produced plants with pale green leaves. The PSG:PL and PSG: YT blends produced premium-quality plants. All other compost blends produced good-quality plants that were similar to the controls.