The impacts of weeds, pests and diseases the New Zealand pastoral sector

Abstract

This chapter addresses the overall costs of pests to New Zealand's pastoral production. However, it is beyond the scope of this contribution to discuss in any detail the entire cohort of pest and weeds present in New Zealand pasture. A compendium of pasture pest species, their characteristics and costs is currently being developed elsewhere (Ferguson et al., in prep). Rather what is presented here is the ecological background that leads to pasture pest impacts and how this translates into current management approaches. While ranges of estimates of overall cost impacts are presented, reference is also made to the difficulty in actually assessing economic impact and how data may be varyingly collected and interpreted.