Who’s the boss? Callies learn the hard way

Downing and his wife Liesl are equity partners, managing a farm near Morrinsville with his parents Lloyd and Olwyn, and they own another farm which employs a contract milker. (Lloyd is a well-known, outspoken Waikato dairy farmer who has held prominent roles in the farming community including Federated Farmers' Waikato president. He is also ending 30 years in the National Fieldays Society, including terms as chairman and president.)

Milking 500 cows on 200ha, Justin says ragwort and Scotch thistles were the first priority. Once these were killed off, attention turned to Californian thistles.

"Apart from looking terrible the patches get bigger and thicker every year if you don't do anything. Cows end up grazing amongst the thistles, reducing the area of productive pasture."

Frustrated with chemical spraying annually for about 10 years, only for Californian thistles to regrow, Downing then tried Tordon PastureBoss. It costs more but contains a new generation herbicide effective at killing weeds with large root systems, such as Californian thistle.

"We found in the past, using another chemical, 24-D, we were spraying the same patches of callies year after year," Downing says. "The thistles would die, but because of their huge root system would just grow back again the next year. With Tordon PastureBoss, we sprayed it once and 90% of callies were gone."

About 10ha was sprayed last summer, boom spraying the big patches and spot spraying areas inaccessible to the tractor.

Though the Tordon costs more, applied at 2L/ha it is worth it because it works, Downing says. The previous chemical, which cost $40/ha, didn't work.

"We now spray all weeds with PastureBoss. We go around with knapsacks, so if we see ragwort or a Scotch thistle, it gets spot sprayed."

The product also kills oxeye daisy, a problem weed on his other farm. "Like Californian thistles, it is now at the stage we can just spot spray."