The FVI lists will not be updated for 2024. Results from the FVI validation trial showed that the economic advantage expected from the higher FVI cultivars selected, from ryegrass DM yield measured at the plot scale, was not captured in this single farmlet scale trial. Until the predicted economic differences among cultivars listed in the FVI model can be demonstrated, the FVI economic rankings will not be published. DairyNZ and the Plant Breeding and Research Association (PBRA) are working to understand this result to strengthen and improve the index. In the meantime, use this page to make informed decisions when choosing ryegrass cultivars for pasture renovation.
Selecting the right cultivar
Selecting the right cultivar for your farm remains just as important as ever. Key factors to consider when making these decisions include:
Dry matter yield
See the PBRA website for more information on the regional dry matter yield of ryegrass cultivars measured in replicated, scientifically-run small plot trials across New Zealand.
Endophyte
Several endophyte options are available and should be considered when ordering seed. It is noted that cultivars with Standard Endophyte (SE) are not recommended as they can cause ryegrass staggers in summer and may reduce milk production at this time. Cultivars with AR1 are not recommended in the Upper North Island as they provide limited protection against black beetle.
For more information on individual endophytes and to ensure you select a well-tested and appropriate endophyte, refer to the PBRA insect and animal safety rating tables.
Ploidy
There are differences in plant characteristics between diploid and tetraploid cultivars. Tetraploid cultivars generally have a higher metabolisable energy (ME) and are more palatable, meaning they require more careful management than diploids to avoid over-grazing (i.e., keep grazing residuals above ~3.5-4 cm or 7-8 clicks on the plate meter).
Tetraploids require careful management in wet conditions to avoid pugging damage on wet soils.
Heading date
Late and very late heading cultivars provide a significant advantage in late spring pasture quality, making pasture management easier, and helping maintain cow pasture intake through this period.
Avoid mixing early and late heading cultivars in the same paddock, as this will dilute the feed quality advantage as the pasture will go to seed over a longer period.
A range of heading dates across the farm will minimise challenges with managing pasture quality. Sowing no more than 50% of the farm in late or very-late cultivars is recommended to minimise early spring feed shortages.
Forage Value Index Validation trial
The FVI validation trial was the first test of the FVI at the farm scale to determine whether dry matter yield differences between higher and lower FVI cultivars emerge as expected and translate into economic rankings matching their relative FVI positions.
The four-year farm systems trial showed that the predicted milk solids production and economic advantage from higher FVI cultivars, based on ryegrass DM yield measured at the plot scale, could not be captured in this single farmlet scale trial.
DairyNZ and the PBRA are committed to working together to understand the root causes of this result. We expect this research will take some time. We want to relaunch the FVI when we are confident the modelled FVI calculations accurately represent on farm performance. The DairyNZ Cultivar Selector Tool was removed on the 19th of March 2024.
For more information on the Forage Value Index research, click here.