Microcapsules are prepared by encapsulating a core material with a capsule shell wall containing glutaraldehyde crosslinked gelatin and at least one water soluble plasticizer that reduces the permeability of the crosslinked gelatin. Optionally, the capsule shell wall also contains a feeding deterrent that dissuades accidental ingestion of the microcapsule. Upon exposing the microcapsules to water, the plasticizer is removed making the shell wall permeable whereby the encapsulated core material is released. Materials such as insecticides, herbicides, plant growth regulating agents, and fungicides may be encapsulated and released at a controlled location, time and rate.
William A. MacMahon; Chel W. Lew; Keith L. Branley