A clathrate of 1-methylcyclopropene with α-cyclodextrin, obtained as a solid particulate product, is modified by comminuting, classifying, or both to obtain a modified particulate. When subjected to identical atmospheric disgorgement conditions of humidity and temperature, identical masses of the modified and unmodified particulates exhibit different rates of 1-methylcyclopropene disgorgement. Specifically, we have found that a smaller mean particle size is inversely related to a greater rate of 1-methylcyclopropene release.