1. Green and bendable canola stems can often straighten up again (somewhat) if lodged due to wind and heavy rain.
2. If lodged due to disease, these plants are unlikely to straighten up. Plants lodged this early due to disease usually contribute little to yield once harvest rolls around.
3. Lodged plants can be more susceptible to spread of sclerotinia stem rot and alternaria from plant to plant.
4. Lodging can influence harvest management decisions, including whether to swath or straight combine the crop.
More on point 4:
A crop heavily lodged and in all directions might be better off swathed when the time comes. This will be slow going either way, but swathing could speed up dry down and make combining much easier.
Straight cutting a lodged crop would be easier if the crop got a pre-harvest dry down herbicide, but penetration of the dry down product can be a challenge in lodged crop. Increased water volumes will improve penetration into the canopy and likely increase efficacy. Higher pressure and smaller droplets will allow for better penetration into the canopy on both lodged crops and crops with a thick canopy.