This paper reports on the effects that livestock have on seed germination of guava (Psidium guajava L.). Experiments here reported were intended to simulate gastric scarification using different soaking periods in a 0.01 N HCl solution alone or combined with rumen treatments. Additional experiments evaluated germination of defecated and nondefecated seeds germinated in petri dishes and in cow dung.
Passage through the digestive tract of cattle did not affect seed germination of guava. Lowered germination was obtained for seeds germinated in cow dung as compared to laboratory germinated seeds. Nevertheless this difference may reflect an inadequate surface-volume ratio of the cow pat used. Large variations in germination between years were recorded. Nothing is known about the effects this may have on the ecology of pasture invasion by guavas.