There is provided a powder composition comprising a collection of particles (I) having median particle diameter of 10 micrometers to 200 micrometers, wherein each of said particles (I) comprises (a) a covering of a fatty compound having melting point of 50°C to 110°C and (b) one or more inner particles (II) comprising one or more complex that contains a cyclopropene compound molecule or a portion of a cyclopropene compound molecule encapsulated in a molecule of a molecular encapsulating agent. Also provided is a slurry comprising water and such a powder. Also provided is a method of contacting plants or plant parts with such a slurry.