Replacement with endophyte strains that do not produce ergovaline has been successfully achieved and led to the release of strain AR542 (MaxQTM) in the USA in 2000. This was later replaced with AR584 (MaxQIITM), a strain that provided all the benefits of AR542 but had improved seed borne transmission and storage characteristics. AR542 expresses peramine and the loline compound NANL, while AR584 expresses peramine and the three loline compounds N-formylloline (NFL) and N-acetylloline (NAL) and N-acetyl norloline (NANL).
The MaxQ brand of endophytes has provided agronomically superior tall fescue cultivars that do not cause any fescue toxicosis symptoms and has been described as a “win-win” outcome. In New Zealand, MaxPTM endophyte reduces damage by African black beetle, Argentine stem weevil, pasture mealy bug, grass grub, and root aphid in a range of tall fescue cultivars. Other insect pests that these ergot alkaloid free endophytes control include fall armyworm, corn flea beetle (Chaetocnema pulicaria), and bird cherry oat aphids.
Tall fescue varieties with MaxPTM in NZ and Australia can be purchased from all good seed retailers. Tall fescue varieties with MaxQTM and MaxQIITM in the USA can be purchased from selected seed distributors.