A new free web app has been designed to help farmers, landowners and councils manage a costly weed that has resisted eradication efforts in New Zealand for over a century. Nassella tussock (Nassella trichotoma) thrives in drought-prone grasslands, mainly in the Canterbury and Marlborough regions and is the only weed in New Zealand to have had its own Act of Parliament, the Nassella Tussock Act 1946. To get rid of it requires lots of hard yakka grubbing it out. Control programmes have reduced the weed’s populations from up to 35,000 plants per hectare to now about 15 plants per hectare. Livestock wont eat the weed which has in some cases, forced farmers to abandon their properties. The new app, developed by AgResearch counts the number of Nassella tussock plants in summer and winter in each of seven different life stages and can advice farmers how best to manage the weed using grubbing. You can find out about Nassella tussock on AgResearch’s AgPest website.