The latest update on stem rust.
Sampling around Lincoln shows that the stem rust season is starting to get underway in perennial ryegrass seed crops.
Overall, it is looking like a low-pressure season in Canterbury; the amounts of inoculum in trials is low and spread is slow. We have seen a reasonable infection period over the last week or so.
Most crops are now past heading, and have a lower than normal level of infection, so there will be a lower number of spores available for germination. However, the wet weather conditions in the past week have been ideal for infection.
In-crop spread is likely to be driven by spores transported by either wind or direct contact within the canopy, rather than through internal spread, which will limit rate of build-up within crops.