We put the difference down to regular, low levels of shattering that occur under normal conditions, without the dramatic impact of a storm or an extremely hot day.
The longer the crop is standing, the more non-PodGuard varieties are likely to shed. In that same period, PodGuard varieties can continue to add yield. Variety trials are normally desiccated and harvested at ‘safe’ timings that suit shattering varieties but are typically too early to show the full advantages of the PodGuard trait.
The extra time all commercial crops are usually given allows PodGuard varieties the chance to gain that ‘paddock advantage.