417 Earthworm Castings as a Media Amendment for Poinsettia Production

An experiment was conducted to determine the effect of earthworm (Eisenia fetida andrei) castings derived from sheep, cow, or horse manures on the growth of poinsettia (Euphorbia pulcherrima `Freedom Red'). Poinsettia cuttings were transplanted to 1-L (15-cm-diameter) plastic pots that were filled with castings:peat moss at 1:0, 1:3, 1:1, 3:1, or 0:1 by volume for each animal manure evaluated. Plants were fertilized using 200 ppm N from a 15-5-25 (N-P2O5-K2O) fertilizer applied with the irrigation water. Total bract area and growth index were greatest in those treatments consisting of 3:1 and 1:1 (castings:peat) from sheep and cow manures, 1:0 (castings:peat) from cow manure and for growth index only, 1:0 (castings:peat) from horse manure. For these two characteristics, 100% sheep manure castings and 100% peatmoss had the lowest values. The time to anthesis was least when poinsettias were grown in 3:1 or 1:1 castings:peat from sheep and cow manures and 1:3, 1:0, or 3:1 from sheep, cow, or horse manure respectively. Anthesis was most delayed when plants were grown in 100% castings from sheep manure.