Large differences exist between yields measured in experiments or simulated in mathematical models and those delivered to factories. This difference was 30% when it was last examined in detail in the 1980’s (Jaggard et al., 1984) and much of it was ascribed to headland management and losses during harvesting. Despite improvements in harvesting (Brown, 2006) and headland management strategies, the differences between simulated or experiment yields and delivered yields remain close to 30% (Jaggard et al., 2007). This project sought to explain these differences.
To quantify, in selected commercial fields and contracts, the factors causing:-
(a) the discrepancies between the potential yields (assessed from a model and from local experiments) and yields in the fields
(b) the discrepancies between yields in fields and delivered yields and how these relate to harvesting, storage and delivery practices.
Outcomes / Key Message For Growers And Industry
It was not possible to draw any conclusions from this work owing to the limited number of sites and lack of agronomy and pesticide information.