Keratin Nursery Pots as Potential Medium for Controlled Release of Copper Ions in Root Growth Control in Theobroma cacao L.

Copper ions at proper levels are essential for plant cell growth and excess copper ions are toxic to root cell growth. The one meter height Theobroma cacao L. plants have roots in 10-15 cm depth nursery pots. “SpinOut®” high in Cu+2 and painted inside the plastic container mitigates against root encircling. Evidence is presented that a similar physicochemical effect can be obtained by incorporating copper ions into a keratin biopolymer matrix extruded into pellets and injection molded into a pot. Sustained controlled release of Cu+2 is obtained for at least six months. The same technology enables highly uniform delivery of the same amount of micronutrients self-consistently pot to pot. This approach would be useful in urban agriculture in which the biomass formulated composition of a soil matrix is especially non-uniform and in which both the plant and the surrounding soil matrix can be competing from among the same micronutrients.