Earthworm Castings as a Substrate Amendment for Chrysanthemum Production
Earthworm castings (vermicompost) were evaluated as a substrate amendment for chrysanthemum [Dendranthema ×grandiflora (Ramat.) Kitam.] `Miramar' production. Vermicompost produced from sheep, cattle, and horse manures were mixed at different ratios with 70 peatmoss: 30 perlite (v/v) to create 12 substrates. The 70 peatmoss: 30 perlite mix at 100% and Sunshine® Mix 1 were used as control substrates. The bulk density, percentage of pore space, and water holding capacity increased as vermicompost content increased while the percentage of air space decreased. At 100% vermicompost, water holding capacity and bulk density were greatest in vermicompost from sheep manure. Plants grown in mixtures of 50% vermicompost from sheep had a greater growth index at harvest, foliar area, number of flowers per pot, and dry weight and fewer days for flower development than plants grown in other substrates. Vermicompost from sheep manure added at 50% by volume was most effective as a substrate amendment for chrysanthemum production.