Broadleaf dock leaf
It is generally assumed that the ensiling process makes most weed seeds non-viable and that weed seeds are not spread in the way they are with hay feeding.
Producers and researchers have based this assumption on observations, but there are no supporting Australian research data.
A Canadian study (see Table 3.8) has examined the effects of ensiling on weed seeds in some detail. In this study, none of the grass seeds survived the ensiling process – no seeds germinated or were viable.
While germination levels were very low with the broadleaf weeds, viability varied from 3 to 30%, indicating that, under favourable conditions, at some point in the future these seeds could germinate.
Other studies have shown that ensiling prevents the germination of broad-leafed dock (Rumex obtusifolius).
The available evidence from these studies indicates that while germination of broadleaf weeds is severely restricted, the seeds of some weeds may remain viable after being ensiled.
Research is required to clarify the situation for common Australian weeds. The important issue is the effect of different ensiling conditions in Australia on weed seed survival. Conditions that may have an effect include silage fermentation, wilting and duration of storage.
