A release composition for agricultural applications which comprises an ECC polymer and a release material associated with the ECC polymer,wherein the release material is a fertilizer, biocide, insecticide or fungicide, and wherein the ECC polymer is defined as a polymer(A) which comprises polymeric molecules having a backbone and comprising at least one moiety which has the formula -b-Cy, wherein the -b-Cy moiety either(a) forms part of a repeating unit of the backbone, the repeating unit having the formula (1) belowwhere Ych is a moiety forming part of the backbone, b is a bond or moiety which links the Cy moiety to Ych, and Cy is a moiety which is associated with other moieties to provide the ECC polymer with crystallinity,or(b) forms part of a terminal unit of the backbone, the terminal unit having the formula (2) below -Yterm- b-Cy (2)where Yterm is a moiety at the end of the backbone, and b and Cy are as defined in formula (1)(B) in which at least 50% by weight of the Cy moieties are present in terminal units of formula (2) and(C) which has a crystalline melting temperature, Tp, of at least 0°C and a ΔH of at least 3J/g which results from association of the Cy moieties.
