During the early 1930s many New Zealand farmers enthusiastically adopted the highly inflammable chemical sodium chlorate as a weedicide against ragwort. This development reflected many aspects of New Zealand farming at the time. Dairying was expanding rapidly, reducing the control of ragwort by grazing with sheep; large areas of land cleared in the post-war boom were reverting to weeds; farmers tended to look to the state to assist with their problems and the Department of Agriculture promoted the use of sodium chlorate; farmers were generally highly literate and were rapidly aware of new possibilities; and there was a continuing shortage of labor in farming. The latter reflected New Zealand’s generally restrictive immigration policies; higher wages and greater freedom in urban employment; changing demography and attitudes to child labor; attitudes to married women working out on the farm; and, perhaps most importantly, the widespread drive for independence from farm workers and neighbors. Sodium chlorate seemed to promise a solution to the control of ragwort without the high financial and personal cost of finding additional labor.