Dealing with thistle

Waimarino Bulletin, Volume 2, Issue 40, 26 March 1985, Page 13

Dealing with thistle

Following last week's California Thistle open day held at Highfield Farm, Pokaka, the King Country's M.A.F. farm advisory officer, Mr Will Wilson, has supplied us with the following comments on controlling the weed. The grdwth of California Thistle needs to be understood, if control is to be achieved. There is an initial rise in thistle growth in N ovember/ December. If these are killed, then a second crop will come through tow'ards the end of January, but these are soft enough for sheep to eat. If grazed a final flush will come by mid-March. Again these are soft enough for sheep to eat. The thistles can be sprayed at these stages. However, it is very costly. What we recommend is to spray November/ December and use stock to graze them on the two subsequent growth periods. In the past there have been extremely variable

results from spraying of thistles. We suspect that these result from the variable follow-up with grazing post spraying. Farmers need to approach the problem systematically, attempting to control a small proportion of the farm each year — say ten or twenty percent. Attempts at total farm control results in a poor kill and is extremely costly.