From Enzo Nastati's "Commentary on Dr Rudolf Steiner’s Agriculture Course" - p1
"...during the course he was asked what one could do against pests, weeds and parasites. The response, that we can all read, essentially suggests that it is adequate to incinerate a sample of the creature in question when certain planets are in front of a particular constellation and later to sprinkle the ashes on the soil. A positive result is not always evoked in the first instance, and it is one of those practices that is easily mocked as witchcraft by those unfamiliar with the concepts.
In fact, whoever knows that each living being is connected to a spiritual archetype also knows that destroying the form of a being causes an equally violent separation from its substance, and a message is sent opposing the incarnation of the spiritual entity which had manifested in that being. This is especially powerful if at that moment the corresponding constellation is ‘active’. In practice the umbilical cord through which the creature draws spiritual sustenance and strength is severed between the incarnated being and its ‘mother’, so the ashes scattered on the ground make that field uncongenial."