Community Structure of Serrated Tussock (\u3ci\u3eNassella trichotoma\u3c/i\u3e) Infested Grasslands

Serrated tussock (Nassella trichotoma) is the most serious perennial grass weed in southeastern Australia, extending over more than a million hectares. Previous control techniques using herbicides and oversowing with competitive pastures are no longer feasible in many of the lower fertility, infested areas. New management solutions need to be found, based upon a better understanding of the ecology of this species. A survey was done to determine the community structure of serrated tussock infested grasslands. Winter growing C3 grasses were closely associated with serrated tussock, while C4 perennial grasses appeared not to be. It is not known if this was due to C4 grasses resisting invasion from, or if they were poor competitors with, serrated tussock. Further research is needed to determine if judicious management of C4 species can effectively control invasion by this devastating weed

Stability and Purity of \u3cem\u3eEpichloë\u3c/em\u3e Endophyte Infection in New Zealand Ryegrass Pastures

Perennial ryegrass (Lolium perenne) in New Zealand pastures is typically infected with the mutualist Epichloë fungal endophyte, which assists the plant in resisting biotic and abiotic stresses. Ryegrass that has naturalised in New Zealand is highly infected with the ‘Standard’ strain of endophyte. This strain provides good protection from a range of invertebrate pests but negatively impacts livestock productivity and health in the warmer seasons of the year. Grass-endophyte associations have been developed between elite perennial ryegrass cultivars and selected endophyte strains to provide protective properties to the host plant and lessen or eliminate the negative effects on animals. While Epichloë-ryegrass associations have been intensively monitored in experimental trials, little has been measured and reported from dairy pastures grazed in commercial settings, particularly with regards to ingress of Standard endophyte. Here we report on presence of endophyte infection and endophyte strain in ryegrass tillers from dairy pastures sampled for up to 7 years in regions of the North and South Islands. In general, infection levels were high (mean 86%). The sown, selected endophytes were the dominant endophyte strains present and these were stable over time. This demonstrates that the industry has been successfully delivering ryegrasses infected with selected endophytes on to dairy farms. The frequency of non-sown endophytes was greater in the North (mean 8%, and mostly Standard endophyte) than the South Island (2%), and Standard endophyte increased over time. There were some notable exceptions to these general effects. Of 23 pastures, two failed to achieve the 70% minimum infection for endophyte to effectively protect against invertebrate pests, and three out of 23 developed high levels of contamination from Standard endophyte. In two cases, the management practices could have contributed to the poor outcome but otherwise the drivers for the low infection or increases in Standard endophyte are unknown

The role of the New Zealand Grassland Association in communicating science to the grassland industry: History, lessons and directions

This is the 80th edition of the NZGA annual publication and the 87th year since the Association was formed in 1931. Much has changed over that time, including some substantial changes to the way that science is funded and communicated to farmers and the wider industry. It is timely to reflect on the history and progress of the Association towards meeting its principal objective: “To foster progress in all matters relating to grassland”. Over the years, many NZGA Presidents have noted issues and challenges faced by the Association. Reading through these papers reminds us that many of the questions and challenges faced in the industry today and by the Association are not new. For example, Banfield (1976) noted the loss of land to forestry as a significant threat. This process has been reversed recently, and with forestry conversion to pasture being a major focus at the Wairakei conference in 2007. Recent Government decisions to plant more trees potentially returns us to that 1975 situation where the subsequent lack of employment associated with locking up land for forestry was noted